ArticleLiterature Review

State of the epidemiological evidence on physical activity and cancer prevention

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Abstract

Physical activity is a modifiable lifestyle risk factor that has the potential to reduce the risk of most major cancer sites. We examined the strength, consistency, dose-response and biological plausibility of an association between physical activity and risk of colon, breast, endometrium, lung, prostate, ovarian, gastric, rectal, pancreatic, bladder, testicular, kidney and haematological cancers. We also estimated the population-attributable risk (PAR) for physical inactivity and cancer in 15 European countries. There is convincing or probable evidence for a beneficial effect of physical activity on the risk of colon, breast and endometrial cancers. The evidence is weaker for ovarian, lung and prostate cancers and generally either null or insufficient for all remaining cancers. Several hypothesised biological mechanisms include a likely effect of physical activity on insulin resistance, body composition, sex steroid hormones and a possible effect on vitamin D, adipokines, inflammation and immune function. Somewhere between 165,000 and 330,000 cases of the six major cancers (breast, colon, lung, prostate, endometrium and ovarian) could have been prevented in 2008 in Europe alone if the population had maintained sufficient levels of physical activity. There is strong and consistent evidence that physical activity reduces the risk of several of the major cancer sites, and that between 9% and 19% of cancer cases could be attributed to lack of sufficient physical activity in Europe. Public health recommendations for physical activity and cancer prevention generally suggest 30-60 min of moderate or vigorous-intensity activity done at least 5d per week.

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... Sex steroid hormones have been proposed as a key mechanistic pathway underlying the association between higher physical activity and reduced breast cancer risk (3)(4)(5). Higher levels of physical activity have, in some instances, been associated with lower levels of circulating sex hormones in both pre-and postmenopausal women (6,7). In premenopausal women, regular, vigorous-intensity exercise may disrupt menstrual function, and potentially delay the onset of menarche (8)(9)(10). ...
... In contrast, increasing physical activity may generate the production and release of anti-inflammatory cytokines while also reducing the production of pro-inflammatory cytokines. Physical inactivity may increase in insulin levels, which in turn may decrease hepatic synthesis of SHBG, increasing the bioavailability of estrogens and androgens (5,161). Increasing physical activity can increase insulin sensitivity and reduce insulin resistance. ...
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Article
The effect of physical activity on breast cancer risk may be partly mediated by sex steroid hormones. This review synthesized and appraised the evidence for an effect of physical activity on sex steroid hormones. Systematic searches were performed using MEDLINE (Ovid), EMBASE (Ovid), and SPORTDiscus to identify experimental studies and prospective cohort studies that examined physical activity and estrogens, progestins, and/or androgens, as well as sex hormone binding globulin (SHBG) and glucocorticoids in pre- and postmenopausal women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the GRADE system was used to appraise quality of the evidence. Twenty-eight randomized controlled trials (RCT), 81 nonrandomized interventions, and six observational studies were included. Estrogens, progesterone, and androgens mostly decreased, and SHBG increased, in response to physical activity. Effect sizes were small, and evidence quality was graded moderate or high for each outcome. Reductions in select sex steroid hormones following exercise supports the biological plausibility of the first part of the physical activity–sex hormone–breast cancer pathway. The confirmed effect of physical activity on decreasing circulating sex steroid hormones supports its causal role in preventing breast cancer. See related reviews by Lynch et al., p. 11 and Drummond et al., p. 28
... There is strong evidence derived from the general population that increased physical activity and reduced body adiposity are associated with decreased cancer risk [6][7][8][9][10][11][12]. Recent research suggests that LS CRC risk can also be moderated by these lifestyle factors [13][14][15][16][17], but the number of studies that investigate the associations between lifestyle and LS cancer risk are scarce. ...
... Various reports in the extant literature have suggested several mechanisms that link physical activity with a reduced cancer risk [11]. For example, physical activity produces multiple beneficial changes in cardiorespiratory systems [39], and being physically active also helps with weight control, as well as with reducing excess adiposity [12]. ...
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Article
Lynch syndrome (LS) increases cancer risk. There is considerable individual variation in LS cancer occurrence, which may be moderated by lifestyle factors, such as body weight and physical activity (PA). The potential associations of lifestyle and cancer risk in LS are understudied. We conducted a retrospective study with cancer register data to investigate associations between body weight, PA, and cancer risk among Finnish LS carriers. The participants (n = 465, 54% women) self-reported their adulthood body weight and PA at 10-year intervals. Overall cancer risk and colorectal cancer (CRC) risk was analyzed separately for men and women with respect to longitudinal and near-term changes in body weight and PA using extended Cox regression models. The longitudinal weight change was associated with an increased risk of all cancers (HR 1.02, 95% CI 1.00–1.04) and CRC (HR 1.03, 1.01–1.05) in men. The near-term weight change was associated with a lower CRC risk in women (HR 0.96, 0.92–0.99). Furthermore, 77.6% of the participants retained their PA category over time. Men in the high-activity group had a reduced longitudinal cancer risk of 63% (HR 0.37, 0.15–0.98) compared to men in the low-activity group. PA in adulthood was not associated with cancer risk among women. These results emphasize the role of weight maintenance and high-intensity PA throughout the lifespan in cancer prevention, particularly in men with LS.
... 80 Lack of physical activity is a stand-alone risk factor for colon, breast, and endometrial cancers. 81 virus was shown to influence the cell-cycle control enzyme APOBEC causing genomic instability and may lead to BC. 68 Other infectious agents such as Helicobacter pylori in gastric 8 Breast Cancer: Basic and Clinical Research physical activity may provide protection from BC by helping women maintain a healthy body weight, lowering hormone levels, and indirectly supporting the immune system. 81,82 Our results are consistent with previous studies that demonstrated a significantly higher risk for BC development in women with close relatives diagnosed with any type of cancer or benign tumors including BBL. 83 A strong family history of BC may be linked to inheritance of the BRCA1 or BRCA2 genetic mutations. ...
... 81 virus was shown to influence the cell-cycle control enzyme APOBEC causing genomic instability and may lead to BC. 68 Other infectious agents such as Helicobacter pylori in gastric 8 Breast Cancer: Basic and Clinical Research physical activity may provide protection from BC by helping women maintain a healthy body weight, lowering hormone levels, and indirectly supporting the immune system. 81,82 Our results are consistent with previous studies that demonstrated a significantly higher risk for BC development in women with close relatives diagnosed with any type of cancer or benign tumors including BBL. 83 A strong family history of BC may be linked to inheritance of the BRCA1 or BRCA2 genetic mutations. 84 Mutations in BRCA1 and BRCA2 genes are identified in approximately 10% of BC patients. ...
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Article
Numerous risk factors for breast cancer (BC) have been identified. High-risk human papilloma virus (HR-HPV) is the etiological agent of cervical cancer and in some cases of head and neck cancer, specifically oropharyngeal cancer, but the role of HR-HPV in evoking neoplasia in BC is still unclear. In this study, all women above the age of 18 visiting the oncology clinic at Al-Azhar university hospital and Ain Shams specialized hospital between the period of February 2017 and March 2018 were invited to participate. We determined the prevalence of HR-HPV genotypes 16, 18, and 31 in breast tissue samples from 72 women with treatment-naïve BC and 15 women with benign breast lesions (BBL) by quantitative real-time PCR (qRT-PCR) and primer sets targeting the E6 and E7 regions. High-risk human papilloma virus DNA was detected in 16 of 72 (22.2%) BC cases (viral load range = 0.3-237.8 copies/uL) and 0 of 15 women with BBL. High-risk human papilloma virus was detected in 14 of 16 (87.5%), 2 of 16 (12.5%), and 0 of 16 (0%) for genotypes 16, 18, and 31, respectively. Forty-three age-matched healthy Egyptian women were enrolled as controls for assessment of local risk factors that can be used to initiate a strategy of BC prevention in Egypt. Assessment of the risk factors demonstrated that low education level, passive smoking, lack of physical activity, family history of cancer, and use of oral contraception were significant risk factors for BC. In conclusion, our results lead us to postulate that HR-HPV infection may be implicated in the development of some types of BC in Egyptian women. In addition, identification of local risk factors can support practical prevention strategies for BC in Egypt.
... The relationship between PA and risk for several different types of cancer has been investigated in depth [20,21]. In recent years, it has become clear that PA reduces the risk for colorectal, mammary and endometrial cancers [18,22]. ...
... Six of the 23 publications (26%) were at level I: experimental study, randomized controlled trial (RCT), or systematic review of RCTs with or without meta-analysis [14,15,18,26,27,32]. A further six studies (26%) were at level II: quasi-experimental studies, systematic review of a combination of RCTs and quasi-experimental studies, or quasi-experimental studies only, with or without meta-analysis [10,19,20,30,33,34]. The remaining 11 publications (48%) were at level III: non-experimental study, and non-experimental studies only, with or without metaanalysis, or qualitative study or systematic review of qualitative studies with or without meta-synthesis [3,4,8,12,13,22,28,30,[35][36][37]. ...
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Article
BACKGROUND: Sedentarism is an important modifiable risk factor in the struggle against cancer. In the last decades, the relationship between physical activity and different types of cancer has been investigated in depth. OBJECTIVE: To provide an overview of the literature on the effectiveness of physical activity in reducing the risk to develop bladder cancer and improving health-related quality of life in patients. METHODS: A systematic review was conducted through a search of the Embase, Cochrane, PubMed, Scopus, and Web of Science (WOS) databases to seek information and PRISMA system to delimitate the research. Outcomes included in searches were physical activity, tobacco consumption, obesity, body mass index, and metabolic syndrome, associated with bladder cancer and quality of life. RESULTS: Database searches identified 394 records, of which 75 were duplicated. A total of 280 articles were excluded based on abstract screening. An additional 16 full-text articles were excluded because they did not meet the eligibility criteria. Overall, 21 of the 23 studies included in the review reported beneficial effects of physical activity in bladder cancer. The majority of papers found that physical activity is a significant factor in reducing the risk of bladder cancer. Moreover, physical activity improves health-related quality of life in bladder cancer survivors, and diminishes both recurrence and mortality in those who engage in regular activity. Lastly, physical inactivity is associated with increased body mass index, obesity, metabolic syndrome, type 2 diabetes and unfavourable energy balance, which led to a greater probability of suffering from bladder cancer. CONCLUSIONS: These data reinforce the importance of promoting a healthy lifestyle to reduce the risk of bladder cancer and to improve survivorship and health-related quality of life of patients.
... 49 Physically active individuals also tend to have higher sunlight exposure and consequently higher levels of vitamin D, which modulates cell proliferation. [50][51][52][53][54][55] Moreover, the responsiveness of specific tumor subtypes to the effects of different types and modalities of exercise is also largely unknown. [56][57][58][59][60][61][62][63] Jones et al 64 investigated whether post-diagnosis exercise could differently affect outcomes in women with early stage BC on the basis of tumor clinicopathologic and molecular features. ...
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Article
Background Physical activity (PA) can play a role in lowering the risk of breast cancer (BC), but also in reducing perioperative complications and treatments related side effects, improving the quality of life and decreasing mortality in BC survivors. PA and nutritional screening are not offered to patients after cancer diagnosis as standard of care, even in high quality breast units. Methods From February 2019 to March 2020, we performed a preoperative physical and nutritional screening in 504 consecutive BC patients waiting for surgery. The screening included an IPAQ questionnaire to evaluate the level of physical activity; nutritional screening with measurement of anthropometric parameters (weight, height, waist and hips circumference, BMI, and waist hip ratio) and evaluation of body composition using Bioelectrical Impedance Analysis (BIA). Results The majority of patients in our series resulted physically inactive: clustering the IPAQ scores, 47% of patients proved to be physically inactive (MET score <700), 34% moderately active (MET score 700-2520), and only 19% physically active (MET score > 2520). In addition, approximately half of the patients (49.01%) resulted overweight or obese, and more than half (55.2%) had a percentage of fatty tissue over the recommended cut off for adult women. Conclusions Our data confirm that assessment of PA levels should become part of the standard preoperative evaluation of BC patients and behavioral interventions should be offered to them, in order to pre-habilitate for surgery and improve outcomes. IPAQ Questionnaire and body composition analysis could be quick and easy screening tools in order to identify which patients may need more support in being active during and after anticancer treatments.
... In 2022, 1.9 million new cancer cases were diagnosed in the US and 609,360 cancer deaths occurred [28]. About one-fifth of all cancer cases are estimated to be attributable to insufficient PA [29]. Most previous studies on associations between PA and cancer were based on self-reported PA measurement, which is prone to misclassification [30], while a few studies were based on CRF assessment [7,[31][32][33][34][35][36][37][38]. ...
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Article
Background: Whether higher cardiorespiratory fitness (CRF) confers protection against cardiovascular disease (CVD) in individuals with manifest hypercholesterolemia is poorly understood. Methods: Participants were 8920 men aged 20–82 years with hypercholesterolemia but no history of CVD and/or cancer and who received a preventive examination at the Cooper Clinic in Dallas, TX, USA, during 1974–2001. CRF was quantified as maximal treadmill test duration and was grouped for analysis as low, moderate, or high based on the traditional Aerobics Center Longitudinal Study cutpoints. Using Cox regression analyses, we computed hazard ratios and 95% confidence intervals for risk of mortality based on CRF. Results: During an average of 17 years of follow-up, 329 CVD and 290 cancer deaths occurred. After control for baseline age, examination year, body mass index, total cholesterol, smoking, alcohol intake, physical activity, hypertension, diabetes, and parental history of CVD, hazard ratios (95% confidence interval) for CVD deaths across moderate and high categories of CRF (with low fit as referent) were: 0.66 (0.50–0.87) and 0.55 (0.39–0.79), respectively. There was an inverse association between CRF and CVD death among normal-weight (trend p < 0.0001), younger (<60 y, trend p = 0.01), and inactive men (trend p = 0.002). However, no significant association was found between CRF and cancer mortality. Conclusions: Among men with hypercholesterolemia, higher CRF was associated with a lower risk of dying from CVD independent of other clinical risk factors. Our findings underscored the importance of promoting CRF in the primary prevention of CVD in patients with hypercholesterolemia.
... PA is generally defined as any bodily movement caused by the contraction of skeletal muscles [13]. Regular PA in all phases of life improves physical wellbeing, lowers the risk of contracting noncommunicable diseases (NCDs; e.g., cardiovascular disease [14], diabetes mellitus [15], obesity [16], cancer [17], lipid profile abnormality [18], and bone density disorders [19]), and lowers the total mortality rate [20]. Furthermore, research has found that PA is linked to better mental health [21], pleasant mood [22], fewer depressive symptoms [23], and a positive affective state on general wellbeing [24]. ...
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Article
Background Regular participation in physical activity (PA) improves physical well-being and reduces the risk of contracting noncommunicable diseases. However, fatigue could negatively impact the PA participation of women in their postpartum period. This study delineated the levels of perceived fatigue and characterized the association between fatigue and the PA patterns of postpartum women. Methods A cross-sectional study was conducted using an online questionnaire distributed to postpartum women living in Saudi Arabia. Their perceived postpartum fatigue (PPF) was assessed using the fatigue severity scale; their PA, using the short form of the International Physical Activity Questionnaires; and their postpartum depression, using the Edinburgh Postnatal Depression Scale. Descriptive statistics were expressed as the mean ± standard deviation for normally distributed variables and as the median (interquartile range) for non-normally distributed variables. Between-group differences were tested using the Mann–Whitney U test for independent samples. To determine the relationship between the study variables, Spearman’s rho correlation coefficient was calculated. Multiple linear regression analysis was performed to explain the role of fatigue severity as an independent predictor of the variance of the PA level. Results A total of 499 postpartum women were divided into the PPF group (43%), who self-reported fatigue, and the non-PPF group (57%), who self-reported no fatigue. There was a significant difference in the median of vigorous PA, and moderate PA which were significantly higher in the non-PPF group than in the PPF group. The women with PPF reported less engagement in walking and a longer sitting duration than the women without PPF. High fatigue severity was associated with lower moderate PA (β = -10.90; p = .005; R 2 = .21) and vigorous PA (β = -04; p < .001; R 2 = .13). These associations remained significant in the regression model after adjustment for the mother’s depression score; age; number of children; body mass index (kg/m ² ); employment status; intake of vitamins B1 (thiamin), C, and D and of Omega-3; and walking metabolic equivalent. Conclusion PPF may reduce the PA of postpartum women. Strategies targeting PPF may buffer its harmful impacts, and thus, improve postpartum women’s health.
... This trend also exists in other animals, such as dogs [14], but these trends are not easily separated from effects of an increased number of cells and greater earlylife growth, which may also play a role. Second, individuals that expend more energy through regular exercise and post-exercise recovery produce more ROS that should increase cancer risk, yet physical activity is well-known to lower cancer risk across a range of different cancers [15] see also References [16][17][18][19][20][21][22][23][24]. Clearly, these observations are opposite to the predictions of the paradigm that proposes links between EE, oxidative stress and cancer, indicating that there is something at least partially incorrect with the view that high EE is tumorigenic. ...
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Article
Energy expenditure (EE) is generally viewed as tumorigenic, due to production of reactive oxygen species (ROS) that can damage cells and DNA. On this basis, individuals within a species that sustain high EE should be more likely to develop cancer. Here, we argue the opposite, that high EE may be net protective effect against cancer, despite high ROS production. This is possible because individuals that sustain high EE have a greater energetic capacity (=greater energy acquisition, expenditure and ability to up-regulate output), and can therefore allocate energy to multiple cancer-fighting mechanisms with minimal energetic trade-offs. Our review finds that individuals sustaining high EE have greater antioxidant production, lower oxidative stress, greater immune function and lower cancer incidence. Our hypothesis and literature review suggest that EE may indeed be net protective against cancer, and that individual variation in energetic capacity may be a key mechanism to understand the highly individual nature of cancer risk in contemporary human populations and laboratory animals. Lay summary The process of expending energy generates reactive oxygen species that can lead to oxidative stress, cell and DNA damage, and the accumulation of this damage is thought to be a major contributor to many ageing related diseases that include cancer. Here, we challenge this view, proposing how and why high energy expenditure (EE) may actually be net protective against cancer, and provide literature support for our hypothesis. We find individuals with high sustained EE have greater energetic capacity and thus can invest more in repair to counter oxidative stress, and more in immune function, both of which reduce cancer risk. Our hypothesis provides a novel mechanism to understand the highly individual nature of cancer, why taller individuals are more at risk, why physically active individuals have lower cancer risk, and why regular exercise can reduce cancer risk.
... In mice with induced endometriosis, CR dramatically stalled lesion growth along with autophagy induction (Yin et al., 2018), indicating that CR activates autophagy in orthotopic endometrium. The preventive role of exercise in endometrial carcinogenesis has been clarified (Tinelli et al., 2008;Friedenreich et al., 2010). Both exercise and CR enhance autophagy via mTORC1 inactivation in a number of tissues (Escobar et al., 2019). ...
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Article
Autophagy, meaning “self-eating,” is a cellular catabolic process that involves lysosomal degradation of cytoplasmic materials. Autophagy contributes to both quality control and energy supply of cells, which are associated with tumorigenesis and tumor development, respectively. Endometrial cancer (EC) is the most common gynecologic cancer, and its incidence is increasing. Although autophagy plays crucial roles in several types of cancer, such as pancreatic ductal adenocarcinoma, its role in EC has not been clearly demonstrated. Activation of the PI3K/AKT/mTOR pathway, which functions to suppress autophagy, is an initial step in type 1 endometrial carcinogenesis, whereas a loss-of-function mutation of TP53 , which augments autophagy via p16 induction, is the main cause of type 2 endometrial carcinogenesis. Mutations in autophagy-related genes, including ATG4C , RB1CC1/FIP200 , and ULK4 , have been reported in EC; thus, an aberrant autophagy mechanism may be involved in endometrial carcinogenesis. Furthermore, the biguanide diabetes drug metformin, treatment with which enhances autophagy via AMPK-mediated mTOR inactivation, has been reported to reduce the risk of EC. These findings suggest that autophagy negatively regulates endometrial carcinogenesis, and autophagy inducers may be useful for chemoprevention of EC. In contrast, autophagy appears to promote EC once it is established. Consistent with this, treatment with chloroquine, an autophagy inhibitor, is reported to attenuate EC cell proliferation. Moreover, chemotherapy-induced autophagy triggers chemoresistance in EC cells. As autophagy has a tumor-promoting function, the combination of chemotherapy and autophagy inhibitors such as chloroquine could be a potent therapeutic option for patients with EC. In conclusion, autophagy plays a dual role in the prevention and treatment of EC. Therefore, targeting autophagy to prevent and treat EC requires diametrically opposed strategies.
... In general, RPA/REX can contribute to overall health, with undeniable benefits for cardiorespiratory fitness (CRF), muscle strength insulin resistance, immune function, and body mass index (BMI) maintenance which can particularly be extended to the prevention of several diseases, including breast cancer [10,11]. ...
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Chapter
Exercise training and regular physical activity have been mentioned as one of the non-pharmacological approaches to enhance breast cancer outcomes. Such evidence encourages health professionals to recommend it as an adjuvant in treatment conditions to improve cardiorespiratory fitness that, can increase the rate of completion of pharmacologic therapies, reduce cancer-related fatigue, and improve muscle strength and quality of life. Research results have highlighted a positive relationship between exercise and breast tumor outcomes, that seem to be dose dependent (the more activity the more protection) and can be mediated through several biological mechanisms. In this chapter, we intend to summarize the current knowledge about the effects of exercise in the regulation of metabolic and steroid hormones, tumor-related inflammation, and the attenuation of cancer-induced muscle wasting, highlighting the exercise designs that can prompt the best results.
... Multiple evidence suggested that low physical activity and high amounts of sedentary time correlate with increased cancer risk in various cancer types [12][13][14]. Previous systematic reviews and meta-analyses revealed that low physical activity and high amounts of sedentary time contribute to an increased risk of CRC [15,16]. ...
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Article
Low physical activity correlates with increased cancer risk in various cancer types, including colorectal cancer (CRC). However, the ways in which swimming can benefit CRC remain largely unknown. In this study, mice bearing tumors derived from CT-26 cells were randomly divided into the control and swimming groups. Mice in the swimming group were subjected to physical training (swimming) for 3 weeks. Compared with the control group, swimming clearly attenuated tumor volume and tumor weight in CT-26 tumor-bearing mice. RNA sequencing (RNA-seq) identified 715 upregulated and 629 downregulated transcripts (including VEGFA) in tumor tissues of mice in the swimming group. KEGG pathway analysis based on differentially expressed transcripts identified multiple enriched signaling pathways, including angiogenesis, hypoxia, and vascular endothelial growth factor (VEGF) pathways. Consistently, IHC analysis revealed that swimming significantly downregulated CD31, HIF-1α, VEGFA, and VEGFR2 protein expression in tumor tissues. In conclusion, swimming significantly attenuates tumor growth in CT-26 tumor-bearing mice by inhibiting tumor angiogenesis via the suppression of the HIF-1α/VEGFA pathway.
... In studies, 5 days a week, especially moderate activities reduce the risk of colon and breast cancer, which has the highest incidence, by about 20-40%, while recurrence rate decreases by 26-40%. Also different types of cancer different treatments performed, although individuals on exercise in cancer therapy to reduce fatigue, aerobic capacity, Nov strength, increasing flexibility, and mental health and quality of life provides a positive effect, it is noted that (Warburton et al., 2007, Friedenreich et al., 2010. ...
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Article
Living conditions, technology and conveniences brought about by modernization, are making people less active on a daily basis. These changes, affect the health status of the people as the level of physical activity gradually decreases and consequently different health problems may occur. Regular exercise is the most effective method of protection from diseases. There is evidence in the literature about physical activity, cardiospiratory status, muscle strength, metabolic health and bone health. There is strong evidence that mortalities, coronary heart disease, high blood pressure, paralysis, diabetes, metabolic syndrome, colon and breast cancer and depression are less common in more active individuals than in less active men and women. There is also strong evidence supporting a better cardiorespiratory and better level of muscular fitness in active individuals, a healthier and better body composition, effective cardiovascular disease and prevention of type II diabetes, and better bone health. It is also stated that regular physical activity with lifestyle modification plays an important role in preventing weight loss and reintroduction of given weight in obese individuals. Studies have shown that regular physical activity decreases the level of low-density lipoprotein (LDL), while that of high-density lipoprotein (HDL) increases. As a result, studies in the literature report a linear relationship between physical activity and health status and draw attention to the protective effect of exercise in the prevention of diseases. It is possible to obtain health benefits by appropriately adapting physical activities to age.
... Insulin can enhance tumor development directly through stimulating cellular proliferation and via activation of the insulin like growth factor (IGF-I) system, which mediates cellular differentiation, proliferation, and apoptosis (15)(16)(17). Insulin can also regulate the synthesis and availability of sex hormones (18). Increased insulin sensitivity is an adaptive response to physical activity (19). ...
... Individuals engaged in regular physical activity exhibit a lower risk of breast cancer incidence and recurrence. 13 Furthermore, exercise training is a safe, feasible, and effective strategy to improve cardiorespiratory fitness in breast cancer survivors in terms ofVO 2peak by preventing or decreasing cancer therapyrelated impairment. 14 High-intensity interval training (HIIT) is an emerging exercise regimen that involves short bouts of exercise at a vigorous intensity, interspersed with brief lowintensity active recovery periods. ...
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Article
Background: Obesity is considered a major risk factor for breast cancer. High-intensity interval training (HIIT) is a time-efficient exercise that significantly advances cardiorespiratory fitness in healthy subjects. Purpose:
... Physical inactivity is related to cancer development. Recent studies showed that physical activity is effective in reducing the risk of various cancers like pancreatic, colon, prostate, lung, ovarian, breast, and endometrial (40)(41)(42). Yu et al. have reported that exercise increased the Pten expression levels of mice skin cells compared with a sedentary control group and prevented the risk of skin cancer development. Also, benefits of regular exercise on the development of hepatocellular carcinoma were reported (43). ...
... Overall, as in the EPIC study, these studies assessed how pre-diagnosis diet and lifetyle recommendations affect cancer mortality. The WCRF recommendations include physical activity as a major lifestyle component, due to its well-known anticancer effects (lower BMI and adiposity; lower sex hormones, insulin, and c-peptide levels; and decreased inflammation and immune response) [5,94]. Indeed, with respect to cancer mortality, the EPIC study also demonstrated that physical exercise, in general and before cancer diagnosis, prevents cancer mortaltiy [45]. ...
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Evidence on the impact of diet, alcohol, body-mass index (BMI), and physical activity on mortality due to cancer and other cancer-related outcomes is still scarce. Herein, we reviewed the contribution of the European Prospective Investigation into Cancer and Nutrition (EPIC) study to the current state of the art on the role of these factors in cancer mortality. We identified 45 studies using a rapid systematic review methodology. Dietary factors associated with reduced cancer mortality included raw vegetable intake; dietary fiber intake; the Mediterranean diet; other dietary scores; other diet patterns including low meat eaters, vegetarians/vegans, or fish eaters; dietary intake (or biomarkers) of some vitamins (e.g., vitamin D, vitamin K2, or Vitamin C); and intake of lignans. Physical activity and following healthy lifestyle recommendations also reduced cancer mortality risk. In contrast, dietary factors associated with higher cancer mortality risk included poor diet quality, consumption of alcohol and soft drinks including juice, and, to a lesser extent, intake of some fatty acids. Excess weight and obesity also increased the risk of cancer mortality. The EPIC study holds valuable information on diet and lifestyle factors and offers a unique opportunity to identify key diet-related factors for cancer mortality prevention.
... These ndings are in line with previous observations of increased cases of obesity in urban regions of Tanzania [20] [28] [29]. Elevated BMI and less physical activity are associated with cardiovascular disease [30] [25], fatty liver disease [26], and some cancers [27] [31] [32]. There is also evidence of initial BMI and increased cancer mortality [33]. ...
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Objective: In Tanzania, cancer is becoming a major public health concern. Risk factors such as poor dietary behavior, high body mass index, physical inactivity, alcohol and tobacco consumption increase the incidence. Limited cancer treatment facilities, prevention programs, and poor knowledge of cancer risk factors and symptoms in the population contribute to late-stage presentation and high mortality rates. The objective of this study is to examine the association of lifestyle factors including body mass index (BMI), physical activity, and dietary behaviors among participants who attended three cancer prevention events in rural and urban areas in Tanzania. Methods: A cross-sectional survey among PrevACamp- attendees in northern Tanzania between August 2019 and February 2020 were chosen. Participants were interviewed using a structured questionnaire on sociodemographic data, medical history, dietary habits, and physical activity, the body mass index was also determined. Results: 235 participants (114 urban/ 121 rural) were included in the survey. Urban residents had higher rates of obesity (p=0.0021) and less physical activity than participants from rural areas (4.63 days [SD=2.03] and 5.50 days [SD=2.00], respectively (p=0.006). Urban dwellers often skip their lunch and prefer to eat a snack. They use salt frequently, consume more processed meat, eat mainly starchy foods, drink more alcohol and sweetened sodas. Conclusion: Rural women more interested in cancer prevention than men. People in rural areas are more physically active and less overweight than those in urban areas. The cause is manifold, yet they hint at a lack of health care for women and a progressing urbanization according to Western patterns. There is an alarming high percentage of overweight among urban dwellers. Although people eat more healthy foods compared to rural populations, they tend to have a high body mass index. Physical inactivity and overweight will be a serious problem in Tanzania in the future, contributing to the risk of cancer.
... [15][16][17] Insulin can also regulate the synthesis and availability of sex hormones. 18 Increased insulin sensitivity is an adaptive response to physical activity. 19 An acute bout of physical activity precedes an increase in insulin-stimulated glucose uptake in the exercised skeletal muscle that lasts for up to 48 hours. ...
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Epidemiologic research suggests that physical activity is associated with a reduced risk of breast cancer, but the causal nature of this link is not clear. Investigating mechanistic pathways can provide evidence of biological plausibility and improve causal inference. This project will examine three putative pathways (sex steroid hormones, insulin signaling, and inflammation) in a series of two-stage systematic reviews. Stage 1 used Text Mining for Mechanism Prioritisation (TeMMPo) to identify and prioritize relevant biological intermediates. Stage 2 will systematically review the findings from studies of (i) physical activity and intermediates and (ii) intermediates and breast cancer. Ovid MEDLINE, EMBASE, and SPORTDiscus will be searched using a combination of subject headings and free-text terms. Human intervention and prospective, observational studies will be eligible for inclusion. Meta-analysis will be performed where possible. Risk of bias will be assessed using the Cochrane Collaboration tool, or the ROBINS-I or ROBINS-E tool, depending on study type. Strength of evidence will be assessed using the GRADE system. In addition to synthesizing the mechanistic evidence that links physical activity with breast cancer risk, this project may also identify priority areas for future research and help inform the design and implementation of physical activity interventions. See related reviews by Swain et al., p. 16 and Drummond et al., p. 28
... In the history, most viruses of epidemics invaded the respiratory system of the human body, which is exposed to nature and is the only one of the major circulatory systems of the human body that is directly connected and open to the outside world [1]. Epidemics are caused by infectious diseases, and there are three main ways of transmission: digestive system transmission, respiratory system transmission, and hematogenous transmission. ...
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The global outbreak of COVID-19 has exposed the deficiency of urban space quality in terms of health and awareness of respiratory infectious diseases.This article analyzes the influencing factors of urban health mechanisms and simulates through infectious disease mechanisms and approaches. Finally Propose corresponding strategies and optimization methods for the optimization of urban space form and structure, and provide corresponding strategies and basis for healthy urban space planning.
... 17 Conversely, physical activity and long-term use of continuous combined estrogen-progestin therapy are associated with a reduced risk of endometrial cancer. 18,19 Interestingly, obesity is associated with earlier age at diagnosis, and with endometrioid-type endometrial cancers. ...
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Article
Endometrial cancer is the most common gynecological malignancy in high- and middle-income countries. Although the overall prognosis is relatively good, high-grade endometrial cancers have a tendency to recur. Recurrence needs to be prevented since the prognosis for recurrent endometrial cancer is dismal. Treatment tailored to tumor biology is the optimal strategy to balance treatment efficacy against toxicity. Since The Cancer Genome Atlas defined four molecular subgroups of endometrial cancers, the molecular factors are increasingly used to define prognosis and treatment. Standard treatment consists of hysterectomy and bilateral salpingo-oophorectomy. Lymphadenectomy (and increasingly sentinel node biopsy) enables identification of lymph node-positive patients who need adjuvant treatment, including radiotherapy and chemotherapy. Adjuvant therapy is used for Stage I-II patients with high-risk factors and Stage III patients; chemotherapy is especially used in non-endometrioid cancers and those in the copy-number high molecular group characterized by TP53 mutation. In advanced disease, a combination of surgery to no residual disease and chemotherapy with or without radiotherapy results in the best outcome. Surgery for recurrent disease is only advocated in patients with a good performance status with a relatively long disease-free interval.
... There are pieces of evidence to show that physical activities such as walking, running and cycling can bring many health benefits to humans [1][2][3], especially in the etiology of many chronic diseases, including cancer, cardiovascular disease, hypertension and obesity [4,5]. Globally, many adults and children do not have enough physical activity to maintain good health [6]. ...
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Many people in the world do not have enough physical activities to maintain good health, which has recently become a threat to public health. In addition to individual genetic and social factors, we considered the geographical environment of the city as a factor that affects these healthy physical activities. We used the location-based data in social media combined with the open geographic data to explore the impact mechanism of urban environmental factors on human running behaviors. This study collected nine urban environmental variables and preference tracks in Beijing’s main urban area. We used the Maximum Entropy Model (MaxEnt) to analyze the relationship between running behaviors and environmental variables and identify suitable areas for running in Beijing. The results showed that: firstly, the variables of attractions, sports and sidewalk density contributed the most to running suitability. Secondly, 47.5% of the main urban areas in Beijing are suitable for running, mainly in the main urban areas with better economic development. Thirdly, the distribution of suitable places for running is unfair in that some places with large populations do not have a matching running environment.
... Physical activity is known to directly and positively affect many risk factors for cardiovascular and neurodegenerative diseases, diabetes, adiposity and obesity, some types of cancer, some aspects of mental health, poor quality of life, and mortality (Blair et al., 1996;Shephard and Balady, 1999;Tuomilehto et al., 2001;Franco et al., 2005;Friedenreich et al., 2010;Umpierre et al., 2011;Wen et al., 2011;Buchman et al., 2012;Das and Horton, 2012;Hallal et al., 2012;Strasser, 2013). Individuals may also benefit from a modest activity: in fact, compared to inactive individuals, those who were even weakly active (about 1.5 h per week) lived 3 years longer (Wen et al., 2011). ...
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Objective : This cross-sectional study evaluates the impact of active or non-active lifestyle in terms of physical, cognitive and social activity on the olfactory function in Elderly Subjects (ES) and aims at looking for a correlation between the time devoted to life activities and the score obtained during the olfactory tests by each individual. Methods : One hundred and twenty-two elderly volunteers were recruited in Sardinia (Italy) and divided into active ES ( n = 60; 17 men, 43 women; age 67.8 ± 1.12 years) and inactive ES ( n = 62; 21 men, 41 women, age 71.1 ± 1.14 years) based on their daily physical activities. The olfactory function was evaluated using the “ Sniffin’s Sticks ” battery test, while the assessment of daily activities was made by means of personal interviews. Results : A significant effect of active or inactive lifestyle was found on the olfactory function of ES ( F (1,120) > 10.16; p < 0.005). A positive correlation was found between the olfactory scores and the number of hours per week dedicated to physical activities (Pearson’s r > 0.32, p ≤ 0.014) in both active and inactive ES. Conclusions : High levels of exercise and non-exercise physical activity are strongly associated with the olfactory function and, consequently, with the quality of life of the elderly. Given the limited physical exercise of elderly people, they can benefit from a more active lifestyle by increasing non-exercise physical activities.
... The protective effects may be greater among lean women, women who have carried children to term, and premenopausal women. The underlying mechanism of this potential protection are not well understood, although it has been hypothesized that the benefit may be due to the effects of physical activity on hormones, energy balance, and the immune system [130]. ...
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Cancer is one of the most important global health problems and it is the most common diagnosed cancer in women in developing and developed countries. Around two-thirds of new cases are in developed countries. Breast cancer is also the most common cancer in females in developing countries with the age standardized incidence rate around 20 per 100,000. The factors that contribute to the international variation in incidence rates are largely due to the differences in reproductive and hormonal factors and the availability of early detection services, Incidence rates in some countries, including the United States, United Kingdom, France, and Australia, sharply decreased from the beginning of the millennium, partly due to lower use of combined postmenopausal hormone therapy. In all countries of the Arab world, breast cancer now occupies the number one position of all female malignancies. Cases tend to be young and almost half of patients are below 50, with a median age of 49-52 years as compared to 63 in industrialized nations. In recent years the higher increase in incidence of cancer worldwide is likely to be in the Eastern Mediterranean Region, where breast cancer is reported as the commonest type of female malignancy in almost all national cancer registries. Breast cancer ranks the first among cancers in Iraqi population and forms 16.28/100000. Additionally, breast cancer account for 34% of the reported cancer cases for the year 2018. The incidence of breast cancer in Iraqi women increased in the last two decades and forms one of the major threats to female health.
... There is strong evidence that lower levels of physical activity are related to poor health outcomes (31). Moreover, reduced physical activity increases the possibilities of developing most prevalent chronic conditions (32)(33)(34)(35)(36)(37), including cancer (38). Furthermore, a growing body of evidence suggests positive effects of physical exercise on cancer specific as well as allcause mortality (39,40). ...
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Prehabilitation has shown its potential for most intra-cavity surgery patients on enhancing preoperative functional capacity and postoperative outcomes. However, its large-scale implementation is limited by several constrictions, such as: i) unsolved practicalities of the service workflow, ii) challenges associated to change management in collaborative care; iii) insufficient access to prehabilitation; iv) relevant percentage of program drop-outs; v) need for program personalization; and, vi) economical sustainability. Transferability of prehabilitation programs from the hospital setting to the community would potentially provide a new scenario with greater accessibility, as well as offer an opportunity to effectively address the aforementioned issues and, thus, optimize healthcare value generation. A core aspect to take into account for an optimal management of prehabilitation programs is to use proper technological tools enabling: i) customizable and interoperable integrated care pathways facilitating personalization of the service and effective engagement among stakeholders; ii) remote monitoring (i.e. physical activity, physiological signs and patient-reported outcomes and experience measures) to support patient adherence to the program and empowerment for self-management; and, iii) use of health risk assessment supporting decision making for personalized service selection. The current manuscript details a proposal to bring digital innovation to community-based prehabilitation programs. Moreover, this approach has the potential to be adopted by programs supporting long-term management of cancer patients, chronic patients and prevention of multimorbidity in subjects at risk.
... Regular physical activity is associated with many health benefits and a reduced risk of many cancers, including lung, prostate and breast cancer [23][24][25][26][27][28][29][30][31][32][33]. Women who exercise regularly were found to have a significantly decreased cancer risk [26,30,31,34]. ...
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Article
Cancer is a disease associated with extreme human suffering, a huge economic cost to health systems, and is the second leading cause of death worldwide. Regular physical activity is associated with many health benefits, including reduced cancer risk. In the past two decades, exercising/contracting skeletal muscles have been found to secrete a wide range of biologically active proteins, named myokines. Myokines are delivered, via the circulation, to different cells/tissues, bind to their specific receptors and initiate signaling cascades mediating the health benefits of exercise. The present review summarizes the existing evidence of the role of the myokine irisin in cancer. In vitro studies have shown that the treatment of various cancer cells with irisin resulted in the inhibition of cell proliferation, survival, migration/ invasion and induced apoptosis by affecting key proliferative and antiapoptotic signaling pathways. However, the effects of irisin in humans remains unclear. Although the majority of the existing studies have found reduced serum irisin levels in cancer patients, a few studies have shown the opposite. Similarly, the majority of studies have found increased levels of irisin in cancer tissues, with a few studies showing the opposite trend. Clearly, further investigations are required to determine the exact role of irisin in cancer.
... Although several risk factors for the development and progression of prostate cancer has been identified, such as family history and genetic factors [2], advanced age [2], and ethnicity [2], these factors are not modifiable. Previous studies have also revealed potential modifiable risk factors, such as obesity [3], dietary factors [4], and physical inactivity [5]. Moreover, in recent years, there has been an increasing interest in the contextual (neighborhood) effect on prostate cancer [6,7]. ...
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Background There is a growing interest in the contextual effect of neighborhood linking social capital on different health outcomes, including cancer. Aims To examine associations between neighborhood linking social capital and incidence and mortality of prostate cancer. Method This cohort study was based on national registers. Between 2002 and 2015, we included 1,196,563 men aged 50 years and above in the analyses. Multilevel logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) for the association between exposure and outcome, adjusting for potential confounding factors. Results The total incidence of prostate cancer and mortality in patients with prostate cancer were 8.22 (per 100) and 1.80 (per 100), respectively, during the follow-up period. Individuals living in neighborhoods with low (OR 0.90; 95% CI 0.88–0.93) and intermediate (OR 0.94; 95% CI 0.92–0.96) linking social capital were less likely to be diagnosed with prostate cancer than those living in neighborhoods with high linking social capital. Opposite effects were observed for mortality; prostate cancer patients living in neighborhoods with low (OR 1.15; 95% CI 1.08–1.23) and intermediate (OR 1.09; 95% CI 1.03–1.14) linking social capital were more likely to die from prostate cancer than those in neighborhoods with high linking social capital. Conclusions Lower neighborhood linking social capital was associated with lower incidence but higher mortality in patients with prostate cancer. These findings suggest that men living in neighborhoods with low linking social capital may need additional surveillance for prostate cancer.
... Similarly, higher physical activity, particularly aerobic activity has been found to be associated with lower levels of perceived stress [8,9]. It has also been reported that people who exercise twice or thrice a week have been reported to exhibit a lower level of stress than those who exercise less frequently or who do not exercise at all [10].In researches, physical activity has been considered as a protective factor for chronic diseases like cardiovascular diseases [11,12], cancer [13,14,15], diabetes [16,17] and hypertension [18]. It has also been reported that regular physical activity helps in slowing down many age-related functional declines. ...
... It is well documented that a higher level of physical activity decreases the risk of colorectal, breast, Journal of Human Kinetics -volume 77/2021 http://www.johk.pl and endometrial cancer (Friedenreich et al., 2010;Kyu et al., 2013). There are new data suggesting the crucial role of exercise in prevention of other types of cancer. ...
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The purpose of this study was to investigate the association between physical effort and DNA methylation in the promoter region of the dopamine transporter gene (DAT1). The research group included 100 athletes (mean age = 22.88, SD = 6.35), whereas the control group were 239 healthy male volunteers matched for age (mean age = 21.69, SD = 3.39). Both, the control and the research group, included individuals with Caucasian origin from the same region of Poland. DNA was extracted from peripheral blood leukocytes using a DNA isolation kit (A&A Biotechnology, Gdynia, Poland). Bisulfite modification of 250 ng DNA was performed using the EZ DNA Methylation Kit (Zymo Research, Orange, CA, USA), according to manufacturer's instructions. The methylation-specific PCR assay was carried out in a Mastercycler epgradient S (Eppendorf, Germany). We observed that the level of general methylation of the CpG island was similar for both groups. Further exploration of individual CpG sites allowed to notice that there were significant differences in methylation status in specific positions. Nonetheless, there was no rule that would indicate either higher or lower methylation of individual sites, four of them were methylated at a higher level (positions 1, 4, 5, 7, 8, 9, 10, 11, 12, 13, 16, 17, 18, 23, 25, 26, 27, 29 and 30), while one showed an inverse trend (position 3). More precise analysis with the usage of Bonferroni correction for multiple tests indicated that differences in CpG site methylation were mainly increased in several positions and decreased in position 3.
... In addition, it has been shown that physical inactivity increases the risk of breast cancer, colorectal cancer (CRC) and possibly prostate cancer [14,15]. There is evidence of an inverse relationship between physical activity, all-cause deaths, breast cancer-related deaths and breast cancer [16]. ...
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Background: Physical activity (PA) is known to be associated with lipid profiles and the risk of both cardiovascular diseases and cancer. The aim of this study was to evaluate the association of objectively measured PA, sedentary behaviour (SB), amount of breaks during SB and number of daily steps with serum lipids in a healthy, Finnish, middle-aged, female population. Methods: The participants (571) were recruited at mammography screening, target group was women aged 50-60 years. A measurement of PA was done with accelerometer, blood lipid profile was assessed, and questionnaires of participants characteristics were sent to participants. Results: The participants with the highest number of daily breaks during SB (≥ 41) had the highest mean concentration of HDL-cholesterol (high density lipoprotein cholesterol, HDL-c) (1.9 mmol/l, standard deviation (SD) 0.4) and the lowest mean concentration of triglycerides (1.0 mmol/l, SD 0.5). HDL-c level was 0.16 mmol/l higher (p < 0.001) in the group with 28-40.9 breaks/day and 0.25 mmol/l higher (p < 0.001) among participants with ≥41 breaks/day than in the group with the fewest breaks during SB (< 28). Those with the most daily steps (≥ 9100) had the highest mean HDL-c level (1.9 mmol/l). HDL-c level was 0.16 mmol/l higher (p < 0.001) among the participants with 5600-9099 steps/day and 0.26 mmol/l higher (p < 0.001) among participants with ≥9100 steps/day than those with the fewest steps (< 5600). The number of daily steps was inversely associated with the triglyceride concentration. From wake-time, participants spent 60% in SB, 18% standing, 14% in light PA, and 9% in moderate-to-vigorous PA (MVPA). PA was associated with serum total cholesterol (TC), HDL-c and triglyceride levels. The mean HDL-c level was the highest in the lowest quartile of SB and in the highest quartile of MVPA. Conclusions: To our knowledge, this is the first study showing a high number of objectively measured breaks during SB is associated with a favourable effect on the level of serum lipids, which may later translate into cardiovascular health among middle-aged women. Trial registration: This study was registered and approved by the Regional Ethics Committee of Tampere University Hospital in Finland (approval code R15137 ).
Article
Perturbation of the insulin/insulin-like growth factor (IGF) signaling system is often cited as a mechanism driving breast cancer risk. A systematic review identified prospective cohort studies and Mendelian randomization studies that examined the effects of insulin/IGF signaling (IGF, their binding proteins (IGFBP), and markers of insulin resistance] on breast cancer risk. Meta-analyses generated effect estimates; risk of bias was assessed and the Grading of Recommendations Assessment, Development and Evaluation system applied to evaluate the overall quality of the evidence. Four Mendelian randomization and 19 prospective cohort studies met our inclusion criteria. Meta-analysis of cohort studies confirmed that higher IGF-1 increased risk of breast cancer; this finding was supported by the Mendelian randomization studies. IGFBP-3 did not affect breast cancer. Meta analyses for connecting-peptide and fasting insulin showed small risk increases, but confidence intervals were wide and crossed the null. The quality of evidence obtained ranged from ‘very low’ to ‘moderate’. There were insufficient studies to examine other markers of insulin/IGF signaling. These findings do not strongly support the biological plausibility of the second part of the physical activity—insulin/IGF signaling system—breast cancer pathway. Robust conclusions cannot be drawn due to the dearth of high quality studies. See related article by Swain et al., p. 2106
Chapter
Epidemiologic research has established various risk factors which are significant in breast cancer aetiology and may be biological, behavioural, social, or physical. The risk factors include modifiable and non-modifiable elements, which act directly or indirectly and are often interrelated. The risk association may vary over time and is relative to the period and length of exposure. This chapter will focus on incidence and mortality rates of breast cancer worldwide together with risk factors associated with the development of breast cancer.
Article
Introdução: A expectativa de vida de pessoas com câncer metastático está aumentando, mas esse grupo de pacientes corre um risco considerável de apresentar problemas psicológicos e de saúde física. Nesse sentido, o exercício físico tem sido um aliado no tratamento de pacientes com metástases ósseas. Objetivo: Realizar uma revisão sistemática e metanálise sobre a segurança e os benefícios do exercício físico em pacientes com metástases ósseas. Método: Metanálise com pesquisa bibliográfica realizada nas bases eletrônicas: PubMed, LILACS, PEDro e Embase. Resultados: Dos 396 estudos, somente dez foram incluídos, com um total de 531 indivíduos. Não foi observado nenhum efeito adverso musculoesquelético durante a intervenção, sendo significativamente seguro o exercício em indivíduos com metástases ósseas. Não houve melhora considerável na capacidade aeróbica, progressão da doença, qualidade de vida, massa magra e gordura corporal. Três dos estudos incluídos avaliaram a dor durante e após a intervenção, demonstrando melhora no escore de dor, assim como a diminuição do uso do analgésico no grupo intervenção. Conclusão: A terapia com exercícios aeróbicos e isométricos e segura para pacientes com metástases ósseas, além de apresentar melhora da dor, mas sem evolução relevante na capacidade aeróbica, na progressão da doença, na massa corporal e na qualidade de vida.
Chapter
Cachexia is a condition characterized by loss of body weight as a result of chronic disease. In the setting of cancer, cachexia is more commonly observed in late stage and metastatic disease and the loss of body weight is attributed to varying combinations of muscle wasting and loss of adipose tissue. Cancer cachexia is a clinically relevant medical issue and is estimated to account for up to 20% of cancer mortality. Additionally, cachexia in cancer patients is associated with reduced tolerance to tumor-directed therapies. Cross-sectional studies support the observation that people with greater levels of physical activity and exercise habits have lower risk of a cancer diagnosis, as well as a lower risk for cancer recurrence. Exercise recommendations for patients with cancer do not differ from those of healthy adults, and patients should strive to be as physically active as their condition allows. The purpose of this chapter is to define cachexia and identify clinical parameters used to diagnose this condition, discuss recommendations for exercise prescription in cancer patients, and provide an overview of the expected physiological responses to both aerobic and resistance training in cancer patients, in order to have a positive impact on the incidence and prevalence of cachexia. In general, aerobic exercise training is not associated with significant increases in body mass or in reversal of body weight loss in cancer patients. In contrast, studies do suggest that resistance exercise training has a role in maintenance or prevention of the onset of cachexia in cancer patients, although differing responses may occur between different cancer types. Therefore, we suggest that structured exercise programs in patients with cancer include resistance training to take advantage of these effects on lean body mass and muscle functional capacity.
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Thesis
Bu araştırma, farklı fiziksel aktivite düzeylerine ve egzersiz alışkanlıklarına sahip yetişkinlerin egzersiz algıları ve benlik algıları arasındaki farkı incelemek amacıyla yapılmıştır. Katılımcıların yaş, boy, cinsiyet, beden kitle indeksi, meslek ve düzenli egzersiz alışkanlık verileri kaydedilmiştir. Katılımcılar uluslararası fiziksel aktivite anketi, egzersiz yarar/engel algısı anketi ve fiziksel benlik algısı anketi kullanılarak değerlendirilmiştir. Çalışmaya katılan bireyler uluslararası fiziksel aktivite anketi sonuçlarına göre üç gruba ayrılmıştır. Fiziksel inaktif grup 111 kişi, minimal aktif grup 108 kişi ve çok aktif grup 24 kişi olacak şekilde çalışmaya katılmıştır. Katılımcıların fiziksel aktivite düzeylerine göre egzersize yönelik yarar algıları karşılaştırıldığında gruplar arası fark istatiksel olarak anlamlı bulunmuştur (p=0.003). Tüm gruplar arasındaki egzersiz engel algıları farkı da istatiksel olarak anlamlı bulunmuştur (p=0.036). Bireylerin fiziksel benlik algıları aktivite düzeylerine göre incelendiğinde, fiziksel benlik algısı alt parametrelerinden spor yeteneği, fiziksel kondisyon, genel fiziksel yeterlilik ve kuvvet parametreleri için istatiksel fark anlamlıyken (p<0.001; p<0.001; p=0.003; p=0.013) vücut çekiciliği parametresi açısından fark yoktur (p=0.351). Bu çalışmanın sonuçlarına göre, farklı fiziksel aktivite düzeylerindeki yetişkinlerin fiziksel benlik algıları ve egzersize bağlı yarar/engel algıları farklıdır. Bireyler farklı egzersiz alışkanlıklarına göre incelendiğinde ise fiziksel benlik algıları ve egzersiz yarar algıları farklı bulunmuştur. Ancak düzenli egzersiz alışkanlıkları ile engel algıları arasında fark yoktur. Bu konuyla ilgili fiziksel aktivite türleri ve egzersiz çeşitleri detaylandırılarak egzersiz yarar/engel algısının araştırılmasına yönelik daha ileri çalışmalar yapılabilir.
Article
An increased level of reactive oxygen species is a key factor in neuronal apoptosis and epileptic seizures. Irisin reportedly attenuates the apoptosis and injury induced by oxidative stress. Therefore, we evaluated the effects of exogenous irisin in a kainic acid (KA)-induced chronic spontaneous epilepsy rat model. The results indicated that exogenous irisin significantly attenuated the KA-induced neuronal injury, learning and memory defects, and seizures. Irisin treatment also increased the levels of brain-derived neurotrophic factor (BDNF) and uncoupling protein 2 (UCP2), which were initially reduced following KA administration. Furthermore, the specific inhibitor of UCP2 (genipin) was administered to evaluate the possible protective mechanism of irisin. The reduced apoptosis, neurodegeneration, and spontaneous seizures in rats treated with irisin were significantly reversed by genipin administration. Our findings indicated that neuronal injury in KA-induced chronic epilepsy might be related to reduced levels of BDNF and UCP2. Moreover, our results confirmed the inhibition of neuronal injury and epileptic seizures by exogenous irisin. The protective effects of irisin may be mediated through the BDNF-mediated UCP2 level. Our results thus highlight irisin as a valuable therapeutic strategy against neuronal injury and epileptic seizures.
Article
Introduction: A systematic literature review was conducted to determine whether physical activity levels during adolescent and young adult years were associated with a reduced lifetime risk of breast cancer among carriers of deleterious mutations in BRCA1 and BRCA2 genes. Methods: Ovid/MEDLINE, Embase, CENTRAL, WOS, and CINAHL were searched for articles including information about adolescent and young adult physical activity and breast cancer incidence among women carrying deleterious BRCA1 and BRCA2 gene mutations (search was initiated in October 2019; last update and full analyses were in March 2021). Independent reviewers screened articles at the title/abstract and full-text levels, resolving differences by consensus with lead authors. The NIH Quality Assessment Tools were used to assess sources of bias. Results: A total of 1,957 unique articles were identified; 5 met inclusion criteria. Samples size ranged from 68 to 1,185. All studies relied on self-reported adolescent and young adult physical activity. One study measured sports involvement; the others measured recreational activity. One large study was null, whereas 4 others showed a reduction in breast cancer incidence later in life with higher adolescent and young adult physical activity (p≤0.05). However, the protection was limited to premenopausal breast cancer in 1 of the studies (OR=0.62; 95% CI=0.40, 0.96; p-trend=0.01). In addition, adolescent and young adult physical activity was associated with older age at breast cancer diagnosis in 1 study (p=0.03). Conclusions: A limited number of studies suggest that adolescent and young adult physical activity may reduce or delay the risk of breast cancer incidence among carriers of deleterious mutations in BRCA1 and BRCA2 genes.
Article
In this work, a novel method is proposed for the assessment of a person’s physical fitness from out-of-breath speech using Gaussian posteriorgram. Based on physical fitness, we consider two categories of persons, physically-active and physically-non-active. A physically-active person is somebody who regularly does physical exercises like jogging, running, cycling, and playing sports. Out-of-breath speech is recorded from a person immediately after he/she undergoes jogging or physical exercise, and it contains higher breath-emission level than normal speech. It is expected that the breath-emission level will be different for physically-active people than the physically-non-active person in the out-of-breath speech. Due to this, speech characteristics of out-of-breath between physically-active and physically-non-active person categories may differ. To capture this variation, posteriorgram-based features are evaluated on Fourier parameters from out-of-breath speech. Performance is evaluated using recordings of out-of-breath speech from 30 persons. In terms of classification rate, the new feature shows an average classification rate of 91.7% using out-of-breath speech, and it outperforms linear prediction coefficients (LPC), mel frequency cepstral coefficients (MFCC) and non-linear Teager energy operator (TEO) based TEO-CB-Auto-Env features.
Thesis
La surexpression du récepteur du facteur de croissance épidermique humain (HER2) dans le cancer du sein est de mauvais pronostic. La thérapie ciblée par trastuzumab améliore la survie globale des patientes mais est associé à une cardiotoxicité, avec notamment une diminution de la fraction d'éjection ventriculaire gauche (FEVG). L’objectif de ce travail de thèse a été d’étudier, chez des patientes suivies en oncologie médicale pour un cancer du sein HER2-positif, traitées exclusivement par trastuzumab, les effets d’un programme de réentrainement à l’effort, individualisé (12 semaines, 55 minutes, 3 fois/semaine), sur cycloergomètre, combinant des intensités modérées et élevées, d’une part sur la toxicité cardiaque, évaluée par la FEVG et la déformation longitudinale du ventricule gauche (DLVG) grâce à une échographie cardiaque et d’autre part sur les adaptations physiologiques à l’exercice, la fatigue, la douleur et la qualité de vie relative à la santé (QdVS). Cinquante-huit patientes ont été randomisées en deux groupes : contrôle (GC ; n=28 ; 49,9 ± 9 ans) et entrainé (GE ; n=30 ; 50,4 ± 7,8 ans). Toutes les variables ont été analysées en pré (T0), en post-intervention (T3) et 3 mois après celle-ci (T6). À T0, la VO2 pic (mL.min-1.kg-1), mesurée par une épreuve d’effort incrémentée, maximale, est faible dans les deux groupes (GE : 24,7 ± 1,4 et GC : 23,8 ± 1,3) sans que la différence ne soit significative. À T3, la FEVG et la DLVG n’ont pas diminué significativement, comparées aux valeurs basales (T0). De plus, le pourcentage de patientes n’ayant pas présenté de toxicité cardiaque est plus important dans le GE (89,3%) que le GC (84%) et chez celles qui ont développé une cardiotoxicité (n=7) la FEVG a diminué de 10,8% à T3. Par ailleurs, la puissance maximale (PM), la VO2 pic et le VO2/FC maximal sont significativement améliorés et les seuils d’adaptation ventilatoire (SV1) et de désadaptation ventilatoire (SV2) sont atteints pour des puissances et VO2 plus élevées dans le GE. En dépit d’une PM plus élevée, la lactatémie de fin d’effort n’est pas significativement différente, témoin d’une moindre acidose métabolique. Les intensités d’entrainement ont augmenté passant de 70 à 87 W en base et de 92 à 110 W au pic. Par ailleurs, les scores de la fatigue générale et physique, de l’interférence et de l’intensité de la douleur sont diminués et ceux de la QdVS sont plus élevés dans le GE. Les augmentations de PM et de VO2 pic sont associées à une moindre fatigue générale et à une plus faible interférence de la douleur et à une meilleure QdVS. Enfin, ni la PM, ni la VO2 pic sont associées à l’augmentation des scores des différentes dimensions du QLQ-C30, excepté l’âge qui est significativement associé à la dimension « fatigue » (OR : 0,081 ; IC95% [0,007-0,893] ; p<0,04). Ainsi, les patientes de plus de 50 ans ont plus de risque d’augmenter leur fatigue.À T6, bien que certaines variables soient légèrement diminuées par rapport à celles mesurées à T3, elles restent supérieures à celles observées à T0. Nos résultats démontrent qu’un programme d’entrainement encadré de 12 semaines est une stratégie efficace qui limite la toxicité cardiaque du trastuzumab, les capacités cardiorespiratoires et métaboliques à l’exercice, diminue la fatigue, la douleur et in fine améliore la qualité de vie des patientes atteintes de cancer du sein. Ces bénéfices ont été retrouvés 3 mois après l’intervention. L’AP doit ainsi faire partie intégrante des soins oncologiques de support pendant et après les traitements.
Article
Background Individuals at increased hereditary risk of cancer are an important target for health promotion and cancer prevention interventions. Health-4-Families uses the Multiphase Optimization STrategy (MOST) framework and is designed to pilot digital delivery strategies for a distance-based, 16-week intervention to promote weight management, healthy diet, and increased physical activity among individuals with BRCA1/BRCA2 or DNA mismatch repair (MMR) pathogenic germline variants. This communication describes participant recruitment and the design of the Health-4-Families pilot study. Methods Health-4-Families is a full-factorial (16 condition) randomized pilot study of four lifestyle intervention components: social networking, telephone or email coaching, text messaging, and self-monitoring. The primary outcome was feasibility and satisfaction with these study components. Participants with pathogenic germline variants were identified via clinic surveillance lists and advocacy organizations and were invited to participate with family members. All participants had to report meeting at least one of the following criteria: (1) having a BMI ≥ 25 kg/m², (2) consuming <5 servings of fruit and vegetables per day, or (3) getting <150 min of moderate-to-vigorous intensity activity per week. Results The majority of screened potential participants with pathogenic variants (83%) were eligible; 86% of those eligible provided informed consent and 79% (n = 104) completed baseline. A total of 206 family members were nominated by study participants and 49% (n = 102) completed baseline. Discussion Recruitment data suggest that individuals with pathogenic germline variants, who are at increased risk for hereditary cancers, are motivated to participate in digital lifestyle interventions. This recruitment success highlights the importance of identifying and prioritizing effective and efficient intervention components for hereditary cancer families. We intend to use the outcomes of our pilot study to inform a fully-powered factorial study for this community.
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CRC is a heterogeneous disease with a multifactorial etiology. Genetic and racial differences with the intervention of environmental and lifestyle factors influence tumor development. CRC is considered a disease of Western civilization, since the incidence has been increasing significantly in recent years in most of them with the improvement in development index; it is also very significant that its incidence has increased in population immigrants in developed countries with the acquisition of the western diet and lifestyle. Most tumors (80%) have a sporadic presentation and as a precursor lesion to the adenomatous polyp. Of this figure, only 5% will evolve to invasive cancer in an average time of 10 years, so it is possible to interfere and modify its natural evolution. It is believed that environment interacts with the individual basically through two mechanisms: diet and lifestyle, which will be the key points on which to act in order to carry out primary prevention in the general population. Several studies indicate that Mediterranean diet models rich in fish, dairy, fiber, and vegetables decrease the risk of CRC compared to Western diet models; the same occurs with diets with a low inflammatory index that are associated with a lower risk of CRC. In contrast, energy diets with a high inflammatory index rich in red meat, processed elements, animal fat, and unsaturated fatty acids lead to an increase in weight gain and the appearance of obesity, and increase the risk of colorectal cancer. Regarding healthy lifestyles, the adoption of lifestyles that promote moderate daily physical activity, a limitation of alcohol consumption, and tobacco cessation are recommended, which contribute to reducing the risk of CRC. In addition, possible treatments for individuals at high risk of developing CRC are analyzed. This strategy is known as chemoprevention.
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We undertook a systematic review and appraised the evidence for an effect of circulating sex steroid hormones and sex hormone–binding globulin (SHBG) on breast cancer risk in pre- and postmenopausal women. Systematic searches identified prospective studies relevant to this review. Meta-analyses estimated breast cancer risk for women with the highest compared with the lowest level of sex hormones, and the DRMETA Stata package was used to graphically represent the shape of these associations. The ROBINS-E tool assessed risk of bias, and the GRADE system appraised the strength of evidence. In premenopausal women, there was little evidence that estrogens, progesterone, or SHBG were associated with breast cancer risk, whereas androgens showed a positive association. In postmenopausal women, higher estrogens and androgens were associated with an increase in breast cancer risk, whereas higher SHBG was inversely associated with risk. The strength of the evidence quality ranged from low to high for each hormone. Dose–response relationships between sex steroid hormone concentrations and breast cancer risk were most notable for postmenopausal women. These data support the plausibility of a role for sex steroid hormones in mediating the causal relationship between physical activity and the risk of breast cancer. See related reviews by Lynch et al., p. 11 and Swain et al., p. 16
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Obesity is considered a major risk factor for breast cancer. High-intensity interval training (HIIT) is a time-efficient exercise that significantly advances cardiorespiratory fitness in healthy subjects. This study aimed to evaluate the effects of HIIT on cardiorespiratory fitness and body composition in survivors of breast cancer who are overweight and obese. Sixty overweight and obese female breast cancer survivors, aged 40 to 60 years, 6 months after completing therapies were included in this study. The patients were randomly allocated to 2 groups: the HIIT group (n = 30; administered HIIT program 3 sessions per week for 8 successive weeks) and the control group (n = 30; received usual care measures). Cardiorespiratory fitness, measured using maximal oxygen uptake (V˙O2 peak ), and body composition were evaluated in patients of both groups at baseline and after the intervention period. V˙O2 peak increased significantly by 3.77 mL⋅kg−1⋅min−1 between pre- and posttreatment (P ˂ .05) in the HIIT group. Body mass indexes in both groups were similar (P > .05). Women in the HIIT group showed significant fat mass changes, fat mass percentage, and lean body mass (P ˂ .05). This study shows that HIIT effectively improves cardiorespiratory fitness and body composition in breast cancer survivors.
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Background: This study aims to characterize patterns of physical activity (PA) and resilience levels, and to examine whether resilience contributes to PA participation among adults during COVID-19 pandemic. Methods: This cross-sectional study was conducted during the quarantine period. The International Physical Activity Questionnaire-Short Form (IPAQ-SF) and the Brief Resilience Scale (BRS) questionnaires were used to assess the study's outcomes. The Kruskal-Wallis test was used to examine the difference in PA across resilience levels. Spearman's correlation coefficient was used to assess the relationship between resilience and PA. Data were reported as medians and interquartile ranges. Results: A sample of 1859 were included in the study (40% aged 26-35 yrs). The findings show that 85% of the respondents engaged in PA and 15% were physically inactive. The majority participated in moderate-intensity PA (71%). The median score was 3.50(0.85), which indicates a medium level of resilience. The positive correlation coefficient was shown between the average score of resilience and both walking (rs =0.01, p<0.001) and vigorous- intensity PA (rs =0.08, p=.007). Data did not show a significant correlation between moderate-intensity PA and resilience score. Conclusions: Greater emphasis on PA engagement after the period of quarantine is needed. Resilience may play an important role in buffering the deleterious impact of quarantine on PA. Key words: Exercise; Physical Activity; Rehabilitation; Mental Health; COVID-19.
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The number of people with cancer is constantly increasing. Thanks to new screening techniques and treatment protocols, the number of survivors is also increasing. However, treatments cause some undesirable side effects that usually persist over time. The level of physical activity of these patients tends to decrease with the diagnosis of cancer and does not usually increase before the end of the treatments or even beyond. However, physical activity is beneficial not only in terms of preventing the progression or recurrence of the disease but also in the fight against side effects related to the disease and its treatments. There are various physical activity recommendations for cancer survivors that will be developed in this article. The project «Sport après cancer. Citoyen sportif, j'agis pour ma santé», developed by the University and the University Hospital of Liège, aims to promote adapted physical activity after cancer, creating a link between outpatient rehabilitation in a hospital setting and the practice of physical activity in a sporting and associative context.
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Resumo A abordagem do cancro da cabeça e pescoço (CCP) é atualmente multidisciplinar. As equipas são constituídas por otorrinolaringologista, cirurgião maxilo-facial, oncologista, radiologista, radioterapeuta, cirurgião plástico, estomatologista, médico-dentista, enfermeiro, psicólogo, assistente social, dietista, fisioterapeuta e terapeuta da fala, entre outros. O sucesso do tratamento depende, também, das escolhas e empenho do doente. Os doentes diagnosticados com CCP têm, não só de lidar com o trauma e o sofrimento da doença, mas também de enfrentar a dificuldade ou incapacidade de comunicação (de voz e de articulação verbal). A deglutição também poderá estar comprometida. A nova condição dos doentes com CCP conduz, muitas vezes, à depressão e à perda de competências profissionais e/ ou sociais. A terapia da fala é de extrema importância para estes doentes porque vai ajudá-los a recuperar as funções perdidas no decorrer dos tratamentos médico-cirúrgicos nomeadamente a deglutição, a articulação verbal e a voz. O terapeuta da fala é o profissional responsável pela avaliação, diagnóstico e reabilitação destas funções, devendo atuar em permanente articulação com a restante equipa multidisciplinar e os familiares do doente desde o período pré-tratamento até ao término da reabilitação, sendo esta articulação determinante para a melhoria da qualidade de vida dos doentes, quer física quer psíquica. Palavras-Chave: perturbações da voz; disfagia; perturbações articulatórias; cabeça e pescoço; reabilitação da voz laríngea, reabilitação da voz alaríngea. Abstract Head and neck cancer (HNC) approach is currently multidisciplinary. The team is composed of several professionals such as an otolaryngologist, maxillofacial surgeon, oncologist, radiologist, radiotherapist, plastic surgeon, stomatologist, dentist doctor, nurse, psychologist, social worker, dietician, physiotherapist and a speech therapist. The success of treatment also depends on the choices and commitment of the patient.Patients diagnosed with head and neck can-cer have not only to deal with the trauma and suffering of the disease but also to cope with difficulty or inability to communicate (voice and speech sounds production). Swal-lowing may also be compromised. The new condition of patients with HNC often leads to depression and loss of professional and/or social skills.Speech therapy is of utmost importance to these patients because it will help them recover lost functions during medical and surgical treatments, such as swallowing, verbal articulation, and voicing. The speech therapist is the professional responsible for the evaluation, diagnosis and rehabilitation of these functions, and must act in permanent articulation with the multidisciplinary team and the patient’s family members from the pre-treatment period until the end of the rehabilitation, being this determinant for the improvement quality of life of patients, whether physical or psychic. Keywords: voice disorders; dysphagia; articulatory disorders; head&neck; laryn-geal voice rehabititation, alaryngeal voice rehabilitation
Article
Evidence is still limited on the influence of sedentary lifestyles on breast cancer (BC) risk. Also, prospective information on the combined effects of both sedentariness and leisure-time physical activity (LTPA) is scarce. We aimed to assess the association of higher sedentary behavior and LTPA (separately and in combination) with the risk of BC in a middle-aged cohort of university graduates. The SUN Project is a follow-up study initiated in 1999 with recruitment permanently open. Baseline assessments included a validated questionnaire on LTPA and sedentary habits. Subsequently, participants completed biennial follow-up questionnaires. Multivariable-adjusted Cox models were used to estimate the hazard ratios (HR) for incident BC according to LTPA, TV-watching, the joint classification of both, and a combined 8-item multidimensional active lifestyle score. We included 10,812 women, with 11.8 years of median follow-up of. Among 115,802 women-years of follow-up, we confirmed 101 incident cases of BC. Women in the highest category of LTPA (>16.5 MET/h-week) showed a significantly lower risk of BC (HR = 0.55; 95% CI: 0.34–0.90) compared to women in the lowest category (≤6 MET/h-week). Women watching >2 h/d of TV exhibited a higher risk (HR = 1.67; 95% CI:1.03–2.72) than those who watched TV <1 h/d. Women in the highest category (6–8 points) of the multidimensional combined 8-item score showed a lower BC risk (HR = 0.35; 95% CI: 0.15–0.79) than those in the lowest category (<2 points) group. There was no significant supra-multiplicative interaction between TV-watching and LTPA. Both low LTPA and TV-watching >2 h/d may substantially increase BC risk, independently of each other.
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Background: Studies across racial/ethnic groups indicate that physical activity (PA) and alcohol consumption are positively associated, and that alcohol consumption is negatively associated with body mass index (BMI), but this relationship is less often evaluated in Hispanics. The purpose of this study was to assess the relationships between alcohol consumption, PA, and BMI in Hispanic adults. Methods: In this secondary data analysis of a Mexican-American cohort, we collected self-reported PA, alcohol consumption, and demographics, and measured height and weight. Linear regression assessed the association between PA and alcohol consumption with BMI, controlling for covariates. Total sample for analyses was n = 3897. Results: We found an inverse relationship between high PA and BMI in the full sample (adjusted estimate = - 0.03, 95% CI - 0.07, - 0.01) and in females, but not males. We also found an inverse relationship between current alcohol use and BMI in the full sample (adjusted estimate = - 0.05, 95% CI - 0.09, - 0.01) and both sexes. There was no significant interaction between PA and alcohol use on BMI. Conclusions: In this study of Mexican-origin adults, current alcohol use and high PA were associated with lower BMIs, but there was no interaction between PA and alcohol use. These results can be used to inform multiple behavior change interventions in Mexican-origin adults.
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The prevalence of obesity, an established epidemiological risk factor for many cancers, has risen steadily for the past several decades in the US and many other countries. Particularly alarming are the increasing rates of obesity among children, portending continuing increases in the rates of obesity and obesity-related cancers for many years to come. Modulation of energy balance, via increased physical activity, has been shown in numerous comprehensive epidemiological reviews to reduce cancer risk. Unfortunately, the effects and mechanistic targets of physical activity interventions on the carcinogenesis process have not been thoroughly characterized. Studies to date suggest that exercise can exert its cancer-preventive effects at many stages during the process of carcinogenesis, including both tumour initiation and progression. As discussed in this review, exercise may be altering tumour initiation events by modifying carcinogen activation, specifically by enhancing the cytochrome P450 system and by enhancing selective enzymes in the carcinogen detoxification pathway, including, but not limited to, glutathione-S-transferases. Furthermore, exercise may reduce oxidative damage by increasing a variety of anti-oxidant enzymes, enhancing DNA repair systems and improving intracellular protein repair systems. In addition to altering processes related to tumour initiation, exercise may also exert a cancer-preventive effect by dampening the processes involved in the promotion and progression stages of carcinogenesis, including scavenging reactive oxygen species (ROS); altering cell proliferation, apoptosis and differentiation; decreasing inflammation; enhancing immune function; and suppressing angiogenesis. A paucity of data exists as to whether exercise may be working as an anti-promotion strategy via altering ROS in initiated or preneoplastic models; therefore, no conclusions can be made about this possible mechanism. The studies directly examining cell proliferation and apoptosis have shown that exercise can enhance both processes, which is difficult to interpret in the context of carcinogenesis. Studies examining the relationship between exercise and chronic inflammation suggest that exercise may reduce pro-inflammatory mediators and reduce the state of low-grade, chronic inflammation. Additionally, exercise has been shown to enhance components of the innate immune response (i.e. macrophage and natural killer cell function). Finally, only a limited number of studies have explored the relationship between exercise and angiogenesis; therefore, no conclusions can be made currently about the role of exercise in the angiogenesis process as it relates to tumour progression. In summary, exercise can alter biological processes that contribute to both antiinitiation and anti-progression events in the carcinogenesis process. However, more sophisticated, detailed studies are needed to examine each of the potential mechanisms contributing to an exercise-induced decrease in carcinogenesis in order to determine the minimum dose, duration and frequency of exercise needed to yield significant cancer-preventive effects, and whether exercise can be used prescriptively to reverse the obesity-induced physiological changes that increase cancer risk.
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The World Health Organisation (WHO) recommends the development of comparable national physical activity surveillance systems to assess trends within and amongst countries as the Global Strategy for Diet and Physical Activity is implemented. To date, the lack of well-standardised measurement instruments has impeded such efforts, but new methodologies are being developed for this purpose. This paper describes the usefulness of the International Physical Activity Questionnaire (IPAQ) in population samples. The Special Eurobarometer Wave 58.2 2002 covered physical activity and provided a good vehicle for assessment of health-enhancing physical activity (HEPA) in the European Union. Data from around 1,000 individuals in each of the 15 member states were collected after careful translation of the questionnaire. IPAQ scoring protocol version 2 was used for definition of activity categories. Data on the prevalence of sufficient total activity, sedentariness, frequent walking and sitting, in total and by gender across European Union (EU) countries showed consistent patterns. The prevalence of sufficient physical activity for health across the member countries was 29%. It ranged from 44% in the Netherlands to 23% in Sweden. The prevalence of sedentariness across countries was in general the mirror image. Regular walking was most prevalent in Spain. Gender was related to physical activity in that men were 1.6 times more likely than women to be sufficiently active, less likely to be sedentary and slightly more likely to sit for at least 6 hours daily. The findings suggest that two thirds of the adult populations of the European countries are insufficiently active for optimal health benefits. As the IPAQ measurement provides information about the patterns of total physical activity and inactivity, the findings indicate possibilities for targeted health promotion efforts.
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We examined how an aerobic exercise intervention influenced circulating estradiol, estrone, sex hormone-binding globulin (SHBG), androstenedione, and testosterone levels, which may be involved in the association between physical activity and breast cancer risk. A two-center, two-arm randomized controlled trial of exercise was conducted in 320 postmenopausal, sedentary women age 50 to 74 years. Participants were randomly assigned to a 1-year aerobic exercise intervention of 225 min/wk (n = 160) or to a control group who maintained their usual level of activity (n = 160). Baseline, 6-month, and 12-month assessments of estrone, estradiol, androstenedione, and testosterone were quantified by radioimmunoassay after extraction, and SHBG was quantified by an immunometric assay. Intent-to-treat analyses were performed using linear mixed models. Blood data were available on 309 women (96.6%) at 12 months. Women in the intervention group exercised an average of 3.6 d/wk for 178 min/wk. At 12 months, statistically significant reductions in estradiol (treatment effect ratio [TER] = 0.93; 95% CI, 0.88 to 0.98) and free estradiol (TER = 0.91; 95% CI, 0.87 to 0.96) and increases in SHBG (TER = 1.04; 95% CI, 1.02 to 1.07) were observed in the exercise group compared with the control group. No significant differences in estrone, androstenedione, and testosterone levels were observed between exercisers and controls at 12 months. This trial found that previously sedentary postmenopausal women can adhere to a moderate- to vigorous-intensity exercise program that results in changes in estradiol and SHBG concentrations that are consistent with a lower risk for postmenopausal breast cancer.
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Physical activity may influence ovarian cancer risk through hormonal, inflammatory, or immune-mediated processes or by suppressing ovulation. In a population-based case-control study of epithelial ovarian cancer, we assessed risk associated with recreational physical activity with a focus on characterizing risk within histologic subtypes. Information was collected during in-person interviews with 812 women with ovarian cancer diagnosed in western Washington State from 2002-2005 and 1,313 controls. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Exercise was assessed according to the average hours and metabolic equivalent (MET)-hours per week and the number of years in which regular recreational activity occurred. Relative to women who reported no regular exercise throughout adulthood, the overall risk of invasive, but not borderline, ovarian cancer was reduced among more active women. Reductions in risk of invasive disease were most evident among women with the greatest frequency of high-intensity activity during adulthood. For serous invasive cancer, women in the uppermost category of MET-hours per week of recreational activity in adulthood had 60% the risk of inactive women (95% CI 0.4-0.9), whereas this level of activity was associated with more than a doubling in risk of endometrioid and clear cell invasive tumors. Our findings are compatible with an overall reduction in risk of invasive epithelial ovarian cancer associated with recreational activity but suggest that this association may differ in women with different histologic types of disease. Inconsistent findings across studies that have considered histologic type indicate that this issue is not yet resolved.
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The possible benefit of lifetime physical activity (PA) in reducing prostate cancer incidence and mortality is unclear. A prospective cohort of 45,887 men aged 45-79 years was followed up from January 1998 to December 2007 for prostate cancer incidence (n=2735) and to December 2006 for its subtypes and for fatal (n=190) prostate cancer. We observed an inverse association between lifetime (average of age 30 and 50 years, and baseline age) total PA levels and prostate cancer risk. Multivariate-adjusted incidence in the top quartile of lifetime total PA decreased by 16% (95% confidence interval (CI)=2-27%) compared with that in the bottom quartile. We also observed an inverse association between average lifetime work or occupational activity and walking or bicycling duration and prostate cancer risk. Compared with men who mostly sit during their main work or occupation, men who sit half of the time experienced a 20% lower risk (95% CI=7-31%). The rate ratio linearly decreased by 7% (95% CI=1-12%) for total, 8% (95% CI=0-16%) for localised and 12% (95% CI=2-20%) for advanced prostate cancer for every 30 min per day increment of lifetime walking or bicycling in the range of 30 to 120 min per day. Our results suggest that not sitting for most of the time during work or occupational activity and walking or bicycling more than 30 min per day during adult life is associated with reduced incidence of prostate cancer.
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We investigated the effect of different exercise modalities on high sensitivity-C reactive protein (hs-CRP) and other inflammatory markers in patients with type 2 diabetes and the metabolic syndrome. Eighty-two patients were randomized into 4 groups: sedentary control (A); receiving counseling to perform low-intensity physical activity (B); performing prescribed and supervised high-intensity aerobic (C) or aerobic+resistance (D) exercise (with the same caloric expenditure) for 12 months. Evaluation of leisure-time physical activity and assessment of physical fitness, cardiovascular risk factors and inflammatory biomarkers was performed at baseline and every 3 months. Volume of physical activity increased and HbA(1c) decreased in Groups B-D. VO(2max), HOMA-IR index, HDL-cholesterol, waist circumference and albuminuria improved in Groups C and D, whereas strength and flexibility improved only in Group D. Levels of hs-CRP decreased in all three exercising groups, but the reduction was significant only in Groups C and D, and particularly in Group D. Changes in VO(2max) and the exercise modalities were strong predictors of hs-CRP reduction, independent of body weight. Leptin, resistin and interleukin-6 decreased, whereas adiponectin increased in Groups C and D. Interleukin-1β, tumor necrosis factor-α and interferon-γ decreased, whereas anti-inflammatory interleukin-4 and 10 increased only in Group D. Physical exercise in type 2 diabetic patients with the metabolic syndrome is associated with a significant reduction of hs-CRP and other inflammatory and insulin resistance biomarkers, independent of weight loss. Long-term high-intensity (preferably mixed) training, in addition to daytime physical activity, is required to obtain a significant anti-inflammatory effect.
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To examine the effects of a 1-year exercise intervention on sex hormone levels in postmenopausal women and whether any effects are mediated by changes in body fat composition. We randomly assigned 189 sedentary postmenopausal women (age 50 to 69 years, body mass index of 22 to 40 kg/m(2)) to an exercise intervention (n = 96) or a control group (n = 93). The intervention combined aerobic and strength training and comprised supervised group sessions and home-based exercises (a total of 2.5 h/wk). Between-group differences in sex hormone levels (at baseline and 4 and 12 months) were examined with generalized estimating equations. In total, 183 women (97%) completed the study. Overall, the exercise intervention did not result in favorable effects on sex hormone levels. Among women who lost more than 2% body fat, declines in all estrogens were not significantly different between exercisers and controls. Androgen levels decreased significantly in the exercise group who lost body fat compared with their peers in the control group. Furthermore, this study confirmed that fat loss was significantly associated with declines in postmenopausal estrogen levels. Although not significant, a similar trend was observed for the androgens. This study confirms that fat loss is associated with changes in postmenopausal sex hormone levels and suggests that exercise may be effective in inducing favorable changes in these hormones.
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Obesity is a risk factor for postmenopausal breast cancer. Elevated estrogen levels are thought to be a growth factor associated with this relationship. However, there is increasing evidence that factors produced directly in adipose tissue, adipokines, specifically adiponectin and leptin, impact breast cancer development. Serum adiponectin levels are reduced in women diagnosed with breast cancer and in vitro studies using human breast cancer cell lines have shown antiproliferative action of adiponectin. In contrast, elevated serum leptin levels were associated with breast cancer in some studies. In mice which lack the leptin receptor or are leptin deficient oncogene-induced mammary tumors were not detected while leptin enhanced proliferation of breast cancer cell lines, particularly those that express estrogen receptors. Of particular interest, one recent study reported that the adiponectin:leptin ratio was reduced in women with breast cancer. Here we speculate that the ratio of these adipokines may be more important in breast cancer than their absolute concentrations. Additionally, we propose strategies to alter this ratio and thus provide protection against the development of breast cancer.
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To examine the prospective association between objectively measured time spent sedentary and insulin resistance and whether this association is independent of moderate- and vigorous-intensity physical activity (MVPA) and other relevant confounders. This was a population-based study (Medical Research Council Ely study) in 376 middle-aged adults (166 men; 210 women) over 5.6 years of follow-up. Physical activity and sedentary time were measured objectively by individually calibrated minute-by-minute heart rate monitoring at both baseline and follow-up. Sedentary time was calculated as the heart rate observations (in minutes) below an individually predetermined threshold (flex heart rate) and expressed as a percentage of total monitored time during waking hours over 4 days. The percentage of time spent above 1.75 x resting heart rate represented MVPA. Fasting plasma insulin was used as a surrogate measure of insulin resistance. Time spent sedentary at baseline was significantly and positively associated with log fasting insulin at follow-up (beta = 0.003, 95% CI 0.0006-0.006, P = 0.015) independent of baseline age, sex, fat mass, fasting insulin, smoking status, and follow-up time. After further adjustment for MVPA, this association was somewhat strengthened (beta = 0.004, 95% CI 0.0009-0.006, P = 0.009). Time spent sedentary predicts higher levels of fasting insulin independent of the amount of time spent at moderate- and vigorous-intensity activity levels. This highlights the importance of reducing sedentary time in order to improve metabolic health, possibly in addition to the benefits associated with a physically active lifestyle.
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Several, but not all, studies have observed increased risks of testicular germ cell cancer (TGCC) associated with bicycling and other recreational activities. To further examine whether physical activity (PA) in adolescence is associated with TGCC risk, the authors conducted a case-control study in western Washington State. Cases (n = 391) were men diagnosed with TGCC, who were identified through a population-based cancer registry. Controls (n = 1,023) were men identified from the general population in western Washington State by using random digit telephone dialing. Participants were queried about various specific PA in grades 7-12 including bicycling, horseback riding, competitive sports, physical education class, as well as moderate, vigorous, and sedentary activities in general. In multivariate analyses, bicycling, vigorous-intensity activities, and sedentary activities were not associated with TGCC risk, while horseback riding and wrestling were associated with decreased risks, and moderate-intensity activities, soccer, basketball, and intermediate duration of competitive activities were associated with increased risks. The lack of internal consistency of the findings within the current study and of findings among prior studies suggests that PA contributes little, if any, to the risk of TGCC.
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Although an inverse association between physical activity and risk of colon cancer is well established, a formal estimate of the magnitude of this risk reduction that includes recent studies is not available. This analysis examines the association by sex and study design, restricting analyses to studies where data for colon cancer alone were available. The authors reviewed published studies through June 2008 examining the association between physical activity and risk of colon cancer. Heterogeneity and publication bias were evaluated and random effects models used to estimate relative risks (RR). Differences by sex and study design were evaluated. A total of 52 studies were included. An inverse association between physical activity and colon cancer was found with an overall relative risk (RR) of 0.76 (95% confidence interval (CI): 0.72, 0.81). For men, the RR was 0.76 (95% CI: 0.71, 0.82); for women, this was little different, (RR=0.79, 95% CI: 0.71, 0.88). The findings from case-control studies were stronger (RR=0.69, 95% CI: 0.65, 0.74) than for cohort studies (RR=0.83, 95% CI: 0.78, 0.88). This study confirms previous studies reporting an inverse association between physical activity and colon cancer in both men and women, and provides quantitative estimates of the inverse association.
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Increased physical activity has been associated with decreased lung cancer risk. However, no previous investigation has examined physical activity in relation to lung cancer histologic types by smoking status. The authors investigated these relations in the National Institutes of Health-AARP Diet and Health Study among 501,148 men and women aged 50-71 years at baseline in 1995-1996. During follow-up to 2003, 6,745 lung carcinomas occurred (14.8% small cell, 40.3% adenocarcinoma, 19.7% squamous cell, 6.1% undifferentiated large cell, 7.2% non-small cell not otherwise specified, and 11.8% carcinoma not otherwise specified). Among former smokers, the multivariate relative risks of small cell, adenocarcinoma, squamous cell, and undifferentiated large cell carcinomas comparing the highest with the lowest activity level (> or =5 times/week vs. inactive) were 0.93 (95% confidence interval (CI): 0.67, 1.28), 0.79 (95% CI: 0.67, 0.94), 0.73 (95% CI: 0.57, 0.93), and 0.61 (95% CI: 0.38, 0.98), respectively. Among current smokers, corresponding values were 0.77 (95% CI: 0.58, 1.02), 0.76 (95% CI: 0.61, 0.95), 0.85 (95% CI: 0.65, 1.11), and 1.10 (95% CI: 0.69, 1.78). In contrast, physical activity was unrelated to lung carcinoma among never smokers (P(interaction) between physical activity and smoking for total lung carcinomas = 0.002). The inverse findings among former and current smokers in combination with the null results for physical activity among never smokers may point toward residual confounding by cigarette smoking as an explanation for the relations observed.
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Available studies on physical activity and ovarian cancer have produced inconsistent findings, with some previous studies reporting a positive association between vigorous physical activity and ovarian cancer risk. We prospectively investigated the relations of self-reported moderate and vigorous physical activity to ovarian cancer in a cohort of 96,216 US women aged 51-72 years at baseline, followed from 1996-1997 to 31 December 2003. During seven years of follow-up, we documented 309 cases of epithelial ovarian carcinoma. In analyses adjusted for age, the relative risks (RRs) of ovarian cancer for individual and joint combinations of moderate and vigorous physical activity such as entirely inactive, neither moderate nor vigorous physical activity, moderate physical activity only, vigorous physical activity only, and both moderate and vigorous physical activity were 0.88, 1.0 (reference), 0.89, 1.05, and 1.08 (95% confidence interval (CI) = 0.81-1.43, respectively. After multivariate adjustment, the relation was essentially unchanged (RR comparing women with both moderate and vigorous physical activity to those with neither moderate nor vigorous physical activity = 1.10; 95% CI = 0.82-1.48). The null association between physical activity and ovarian cancer persisted in subgroups of women as defined by body mass index, parity, oral contraceptive use, menopausal hormone therapy, family history of ovarian cancer, and other variables (all p values for interaction >0.05). Neither moderate nor vigorous physical activity showed a statistically significant association with ovarian cancer in this large cohort of women.
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Research on physical activity and health has pointed clearly to increasing the time that adults spend doing moderate-to-vigorous intensity activities: 30 minutes a day is generally recommended. Recent evidence, however, underlines the importance of also focusing on sedentary behaviours -- the high volumes of time that adults spend sitting in their remaining 'non-exercise' waking hours. In the context of contemporary interest in physical activity and health, we provide a brief overview of recent evidence for the distinct relationships between 'too much sitting' and biomarkers of metabolic health, and thus with increased risk of type 2 diabetes, cardiovascular disease and other prevalent chronic health problems. Particular concerns for this new field include the challenges of changing sedentary behaviours in the context of ubiquitous environmental and social drivers of sitting time; examining the effects of interventions for reducing or breaking-up sitting time; and, identifying the most-relevant implications for clinical and public health practice.
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We studied the relation between self-reported physical activity and cancer in the first National Health and Nutrition Examination Survey (NHANES I) cohort, originally examined between 1971-75, and followed prospectively through the Epidemiologic Follow-up Study (NHEFS), conducted between 1982-84. Among 5,138 men and 7,407 women 25-74 years old, for nonrecreational activity we observed increased risk of cancer among inactive individuals compared to very active persons (for men, relative risk [RR] 1.8, 95% confidence interval [CI] = 1.4, 2.4; for women RR 1.3, 95% CI = 1.0, 1.8). These findings were unchanged after adjustment for cigarette smoking, body mass index (BMI), and other potential confounders. Sites which demonstrated stronger inactivity-cancer associations included colorectum (RR 1.6, 95% CI = 0.7, 3.5) and lung (RR 1.6; 95% CI = 1.2, 3.5) among men, and breast (post-menopausal) (RR 1.7; 95% CI = 0.8, 2.9) and cervix (RR 5.2; 95% CI = 1.4, 14.5) among women, although these findings for women were based on relatively few cases. The association between inactivity and cancer was greater among persons of moderate (or lower) BMI, those cases occurring three or more years after baseline, and, in women, those more than 60 years old. In contrast, recreational exercise showed little relation to cancer, with the exception of prostate cancer. The results suggest that inactive individuals are at increased risk of cancer.
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We examined the association between self-reported occupational and recreational physical activity and the subsequent risk of colorectal cancer in a population-based cohort in Norway. During a mean follow-up time of 16.3 years for males and 15.5 years for females, 236 and 99 colon cancers and 170 and 58 rectal cancers were observed in males and females, respectively, among 53,242 males and 28,274 females who attended the screening between 1972 and 1978. Physical activity at a level equivalent to walking or bicycling for at least four hours a week during leisure-time was associated with decreased risk of colon cancer among females when compared with the sedentary group (RR = 0.62, 95% CI 0.40-0.97). Reduced risk of colon cancer was particularly marked in the proximal colon (RR = 0.51, 95% CI 0.28-0.93). This effect was not observed for occupational physical activity alone, probably due to a narrow range of self-reported physical activity at work among females. However, by combining occupational and recreational physical activity we observed an inverse dose-response effect as increasing total activity significantly reduced colon cancer risk (P for trend = 0.04). Among males 45 years or older at entry to the study, an inverse dose-response effect was observed between total physical activity and colon cancer risk (P for trend = 0.04). We also found in males a stronger preventive effect for physical activity in the proximal as compared to distal colon. In addition, we found a borderline significant decrease in colon cancer risk for occupational physical activity in males 45 years or older when compared to the sedentary group (RR = 0.74, 95% CI 0.53-1.04). All results were adjusted for age, body mass index, serum cholesterol and geographic region. No association between physical activity and rectal cancer was observed in males or females. The protective effect of physical activity on colon cancer risk is discussed in regard to energy balance, dietary factors, age, social class, body mass index and gastrointestinal transit time.
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Variation in colorectal cancer rates between countries and within ethnic groups upon migration and/or Westernization suggests a role for some aspects of Western lifestyle in the etiology of this disease. We conducted a population-based case-control study in the multiethnic population of Hawaii to evaluate associations between colorectal cancer and a number of characteristics of the Western lifestyle (high caloric intake, physical inactivity, obesity, smoking, and drinking) and some of their associated diseases. We interviewed in person 698 male and 494 female United States-born or immigrant Japanese, Caucasian, Filipino, Hawaiian, and Chinese patients diagnosed in 1987-1991 with colorectal cancer and 1192 population controls matched on age, sex, and ethnicity. Conditional logistic regression was used to estimate odds ratios adjusting for dietary and nondietary risk factors. Place of birth and duration of residence in the United States were unrelated to colorectal cancer risk. Energy intake (independent of the calorie source) and body mass index were directly associated with risk, and lifetime recreational physical activity was inversely associated with risk. The associations with these factors were independent of each other, additive (on the logistic scale) and stronger in men. When individuals were cross-categorized in relation to the medians of these variables, those with the higher energy intake and body mass index and lower physical activity were at the highest risk (for males, OR, 3.0; 95% confidence interval, 1.8-5.0, and for females, OR, 1.7; 95% confidence interval, 1.0-3.2). Smoking in the distant, as well as recent, past and alcohol use were directly associated with colorectal cancer in both sexes. Individuals with a history of diabetes or frequent constipation were at increased risk for this cancer, whereas past diagnosis of hypercholesterolemia was inversely associated with risk. The findings were consistent between sexes, among ethnic groups, and across stages at diagnosis, making bias an unlikely explanation. These results confirm the data from immigrant studies that suggest that the increase in colorectal cancer risk experienced by Asian immigrants to the United States occurred in the first generation because we found no difference in risk between the immigrants themselves and subsequent generations. They also agree with recent findings that suggest that high energy intake, large body mass, and physical inactivity independently increase risk of this disease and that a nutritional imbalance, similar to the one involved in diabetes, may lead to colorectal cancer.
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Purpose To review systematically all publications of the effects of exercise on endogenous insulin-like growth factor (IGF) to clarify the nature of this association. Methods We reviewed 115 research studies in humans by subgroup of population (age; sex; athletic training status), physical activity exposure (resistance vs. aerobic activity; duration of activity) and study design. Results Fifty percent of studies reviewed found no difference in total circulating IGF-1 as a result of exercise; 37% showed an increase, and 13% observed decreases in IGF-1 levels with exercise. Age influenced the effects of exercise on IGF levels. Exercise appeared to decrease IGF-1 levels in children, but to increase levels in young adults. Similar results were found for IGFBP-3. Conclusions It is not yet possible to determine if exercise affects IGF levels. Important methodologic differences among studies, as well as concerns about study quality, limit the ability to draw firm conclusions.
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b>OBJECTIVE —We examined the associations of television viewing time with fasting plasma glucose (FPG) and 2-h postchallenge plasma glucose (2-h PG) levels in Australian adults. RESEARCH DESIGN AND METHODS —A total of 8,357 adults aged >35 years who were free from diagnosed diabetes and who attended a population-based cross-sectional study (Australian Diabetes, Obesity and Lifestyle Study [AusDiab]) were evaluated. Measures of FPG and 2-h PG were obtained from an oral glucose tolerance test. Self-reported television viewing time (in the previous week) was assessed using an interviewer-administered questionnaire. Homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and ß-cell function (HOMA-%B) were calculated based on fasting glucose and insulin concentrations. RESULTS —After adjustment for confounders and physical activity time, time spent watching television in women was positively associated with 2-h PG, log fasting insulin, and log HOMA-%B and inversely associated with log HOMA-%S ( P < 0.05) but not with FPG. No significant associations were observed with glycemic measures in men. The ß-coefficients across categories of average hours spent watching television per day (<1.0, 1.0–1.9, 2.0–2.9, 3.0–3.9, and ≥4.0) for 2-h PG in women were 0 (reference), 0.009, 0.047, 0.473, and 0.501, respectively ( P for trend = 0.02). CONCLUSIONS —Our findings highlight the unique deleterious relationship of sedentary behavior (indicated by television viewing time) and glycemic measures independent of physical activity time and adiposity status. These relationships differed according to sex and type of glucose measurement, with the 2-h PG measure being more strongly associated with television viewing. The findings suggest an important role for reducing sedentary behavior in the prevention of type 2 diabetes and cardiovascular disease, especially in women.<br /
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The purpose of this review is to articulate how progress in epidemiological research on physical activity and cancer prevention can be made. This report briefly reviews the accumulated evidence for an etiological role of physical activity in the prevention of cancer of the colon, breast, prostate, testes, lung, endometrium, and ovary and summarizes the evidence for a causal association for each of these sites. The evidence for a causal association between physical activity and colon and breast cancers is found to be "convincing," for prostate cancer to be "probable," for lung and endometrial cancers to be "possible," and for testicular and ovarian cancers to be currently "insufficient" to make any definitive conclusions. The emerging literature on physical activity and cancer prevention intervention studies is presented, and an overview of the literature on physical activity intervention is also provided. Given the level of evidence that is currently available for the associations between physical activity and cancer, it is argued that for additional progress to be made in this field, there need to be intervention studies on physical activity and cancers of the colon and breast. For the remaining cancer sites, better designed observational epidemiological studies are needed that address the identified methodological limitations found in previous studies. These limitations include crude and incomplete physical activity assessment, lack of adequate control for confounding and effect modification, as well as a lack of consideration of the underlying biological mechanisms that are operative. This review concludes with detailed recommendations for future research in this field.
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This chapter discusses epidemiologic studies of physical activity and cancer prevention. There is a large body of epidemiologic data on the relation between physical activity and the risk of developing cancer. Although the direct evidence on this relation comes only from observational studies, randomized clinical trials have provided indirect evidence by examining the association of physical activity with markers of cancer risk, such as body weight and hormone levels. Moreover, several plausible biological mechanisms support the hypothesis that higher levels of physical activity decrease the incidence of various cancers. The data are clearest for colon and breast cancer, with case-control and cohort studies supporting a moderate, inverse relation between physical activity and the development of these cancers.
Article
OBJECTIVE: To assess the epidemiologic evidence for the association between physical activity and endometrial cancer risk, taking into account the methodologic quality of each study. DESIGN: Systematic review, best evidence synthesis. DATA SOURCES: Studies were identified through a systematic review of literature available on PubMed through December 2006. REVIEW METHODS: We included cohort and case-control studies that assessed total and/or leisure time and/or occupational activities in relation to the incidence of endometrial cancer. The methodologic quality of the studies was assessed with a comprehensive scoring system. RESULTS: The included cohort (n = 7) and case-control (n = 13) studies consistently show that physical activity is associated with a decreased risk of endometrial cancer. The best evidence synthesis showed that the majority (80%) of 10 high-quality studies found risk reductions of >20%. Pooling of seven high-quality cohort studies that measured total, leisure time, or occupational activity showed a significantly decreased risk of endometrial cancer (summary estimate: OR, 0.77; 95% CI, 0.70-0.85) for the most active women. Case control studies with relatively unfavorable quality scores reported divergent risk estimates, between 2-fold decreased and 2-fold increased risk. Effect modification by body mass index or menopausal status was not consistently observed. Evidence for an effect of physical activity during childhood or adolescence was limited. CONCLUSIONS: Physical activity seems to be associated with a reduction in the risk of endometrial cancer, which is independent of body weight. Further studies, preferably prospective cohort studies, are needed to determine the magnitude of the risk reduction and to assess which aspects of physical activity contribute most strongly to the reduced risk and in which period of life physical activity is most effective
Article
BACKGROUND: Physical activity has been associated with a decreased risk for breast cancer. The biological mechanism(s) underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones either direct, or indirect by preventing overweight and abdominal adiposity. In order to get more insight in the causal pathway between physical activity and breast cancer risk, we designed the Sex Hormones and Physical Exercise (SHAPE) study. Purpose of SHAPE study is to examine the effects of a 1-year moderate-to-vigorous intensity exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether the amount of total body fat or abdominal fat mediates the effects. METHODS/DESIGN: In the SHAPE study, 189 sedentary postmenopausal women, aged 50-69 years, are randomly allocated to an intervention or a control group. The intervention consists of an 1-year moderate-to-vigorous intensity aerobic and strength training exercise programme. Participants allocated to the control group are requested to retain their habitual exercise pattern. Primary study parameters measured at baseline, at four months and at 12 months are: serum concentrations of endogenous estrogens, endogenous androgens, sex hormone binding globuline and insuline. Other study parameters include: amount of total and abdominal fat, weight, BMI, body fat distribution, physical fitness, blood pressure and lifestyle factors. DISCUSSION: This study will contribute to the body of evidence relating physical activity and breast cancer risk and will provide insight into possible mechanisms through which physical activity might be associated with reduced risk of breast cancer in postmenopausal women
Article
BACKGROUND: Many epidemiologic studies have found an association between physical activity and breast cancer risk, although this has not been a consistent finding. METHODS: Studies were identified through a systematic review of literature available on PubMed through February 2006. We included all cohort and case-control studies that assessed total or leisure time activities in relation to occurrence or mortality of breast cancer. The fully adjusted risk estimates and 95% confidence intervals for the highest versus lowest level of activity were documented for each study as well as evidence for a dose-response relationship. Methodologic quality was also assessed. Due to statistical and methodologic heterogeneity among studies, we did not carry out statistical pooling. To draw conclusions, we performed a best-evidence synthesis taking study quality into account. RESULTS: Nineteen cohort studies and 29 case-control studies were evaluated. There was strong evidence for an inverse association between physical activity and postmenopausal breast cancer with risk reductions ranging from 20% to 80%. For premenopausal breast cancer, however, the evidence was much weaker. For pre- and postmenopausal breast cancer combined, physical activity was associated with a modest (15-20%) decreased risk. Evidence for a dose-response relationship was observed in approximately half of the higher-quality studies that reported a decreased risk. A trend analysis indicated a 6% (95% confidence interval = 3% to 8%) decrease in breast cancer risk for each additional hour of physical activity per week assuming that the level of activity would be sustained. CONCLUSIONS: There is evidence for an inverse association between physical activity and breast cancer risk. The evidence is stronger for postmenopausal breast cancer than for premenopausal breast cancer
Article
In Japan the incidence of cervical cancer has been high, but has recently been decreasing gradually, while the incidence of endometrial cancer is running at lower levels but is gradually increasing. To clarify the common and/or specific risk and/or protective factors of cervical cancer (CC) in contrast with endometrial cancer (EC), a comparative case-control study was conducted at the Aichi Cancer Center Hospital, Japan. In total, 556 CC cases and 145 EC cases were included and 26,751 women, confirmed as free of cancer, were chosen as the common control group. Odds ratio and its 95% confidence interval (95%CI) for each exposure variable were estimated by using an unconditional logistic regression model adjusted for age and first-visit year. Habitual smoking and experience of pregnancy increased the risk of CC, while decreasing the risk of EC. Greater body mass index (>20), daily intake of fruit and more frequent intake of boiled or broiled fish (>1–2 times/week) decreased the risk of CC, whereas they increased the risk of EC. Daily intake of milk decreased the risk of CC. The results obtained from this study suggest that several EC-increasing risk factors are in fact CC-decreasing determinants. The observed risk reduction in both CC and EC by physical exercise and dietary control for health is noteworthy from the public health standpoint and warrants further investigation.
Article
Factors influencing circulating estrogen levels, insulin-mediated pathways or energy balance through obesity-related mechanisms, such as physical activity, have been proposed as potential risk factors for endometrial cancer. We examined measures of physical activity in relation to endometrial cancer risk in the American Cancer Society Cancer Prevention Study II Nutrition Cohort, a prospective study of cancer incidence and mortality, using information obtained at baseline in 1992. From 1992 to 2003, 466 incident endometrial cancers were identified among 42,672 postmenopausal women with intact uteri who were cancer-free at enrollment. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) while adjusting for potential confounders. To assess the role of body mass index (BMI) in this relationship, we computed multivariate RR with and without adjustment for BMI and stratifying by BMI. All measures of physical activity and the avoidance of sedentary behavior were associated with lower endometrial cancer risk. Baseline recreational physical activity was associated with 33% lower risk (RR = 0.67, 95% CI 0.44-1.03 for 31.5+ vs. <7 MET-hr/week, trend p = 0.007) in the multivariate model without BMI. However, the trend was attenuated after further adjustment for BMI (trend p = 0.18). BMI significantly modified the association between physical activity and endometrial cancer risk (heterogeneity of trends p = 0.01). The inverse relationship was seen only among overweight or obese women (trend p = 0.003) and not in normal weight women (trend p = 0.51). In summary, light and moderate physical activity including daily life activities were associated with lower endometrial cancer risk in our study, especially among women who are overweight or obese.