Article

Randomized Controlled Trial of Aerobic Exercise on Insulin and Insulin-like Growth Factors in Breast Cancer Survivors: The Yale Exercise and Survivorship Study

Department of Epidemiology and Public Health, Yale School of Medicine, P.O. Box 208034, New Haven, CT 06520-8034, USA.
Cancer Epidemiology Biomarkers & Prevention (Impact Factor: 4.32). 01/2009; 18(1):306-13. DOI: 10.1158/1055-9965.EPI-08-0531
Source: PubMed

ABSTRACT High insulin and insulin-like growth factor-I (IGF-I) levels may be associated with an increased breast cancer risk and/or death. Given the need to identify modifiable factors that decrease insulin, IGF-I, and breast cancer risk and death, we investigated the effects of a 6-month randomized controlled aerobic exercise intervention versus usual care on fasting insulin, IGF-I, and its binding protein (IGFBP-3) in postmenopausal breast cancer survivors.
Seventy-five postmenopausal breast cancer survivors were identified from the Yale-New Haven Hospital Tumor Registry and randomly assigned to an exercise (n = 37) or usual care (n = 38) group. The exercise group participated in 150 minutes per week of moderate-intensity aerobic exercise. The usual care group was instructed to maintain their current physical activity level. A fasting blood sample was collected on each study participant at baseline and 6 months. Blood levels of insulin and IGF were measured with ELISA.
On average, exercisers increased aerobic exercise by 129 minutes per week compared with 45 minutes per week among usual care participants (P < 0.001). Women randomized to exercise experienced decreases in insulin, IGF-I, and IGFBP-3, whereas women randomized to usual care had increases in these hormones. Between-group differences in insulin, IGF-I, and IGFBP-3 were 20.7% (P = 0.089), 8.9% (P = 0.026), and 7.9% (P = 0.006), respectively.
Moderate-intensity aerobic exercise, such as brisk walking, decreases IGF-I and IGFBP-3. The exercise-induced decreases in IGF may mediate the observed association between higher levels of physical activity and improved survival in women diagnosed with breast cancer.

Download full-text

Full-text

Available from: Susan T Mayne, Jun 21, 2015
0 Followers
 · 
94 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Over the past decade there has been increasing research and clinical interest in the role of exercise therapy/rehabilitation as an adjunct therapy to improve symptom control and management following a cancer diagnosis. More recently, the field of 'exercise - oncology' has broadened in scope to investigate whether the benefits extend beyond symptom control to modulate cancer-specific outcomes (i.e., cancer progression and metastasis). Here we review the extant epidemiological evidence examining the association between exercise behavior, functional capacity/exercise capacity, and cancer-specific recurrence and mortality as well as all-cause mortality individuals following a cancer diagnosis. We also evaluate evidence from clinical studies investigating the effects of structured exercise on blood-based biomarkers associated with cancer progression/metastasis as well findings from preclinical investigations examining the effects and molecular mechanisms of exercise in mouse models of cancer. Current gaps in knowledge are also discussed.
    Brain Behavior and Immunity 05/2012; 30. DOI:10.1016/j.bbi.2012.05.001 · 6.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective Although regular physical activity is associated with lower all-cause and disease-specific mortality among breast cancer survivors (BCS), most BCS do not meet its recommended guidelines. Attention function, a domain of cognition, is essential for daily tasks such as exercising, a form of planned physical activity. We tested the hypotheses that lower self-reported attention function in BCS would be associated with less exercise and higher body mass index (BMI) by comparing a group of 505 young BCS (45 years or younger at diagnosis and 3-8 years post-treatment) with 466 acquaintance controls (AC).Methods The groups were compared on self-reported physical and psychological outcomes. Mplus software was used to perform confirmatory structural equation modeling with a robust maximum likelihood estimator to evaluate hypothesized relationships among variables. The criteria for good model fit were having root mean square error of approximation (RMSEA) < 0.06, comparative fit index (CFI) > 0.95, and standardized root mean square residual (SRMR) < 0.08. Modification indices were used to better fit the model.ResultsThe final model demonstrated good fit, with RMSEA = 0.05, CFI = 0.98, and SRMR = 0.03. After controlling for demographics, parameter estimates revealed that, compared with AC, young BCS reported worse attention function (p < 0.001), more depressive symptoms (p < 0.001), and more fatigue (p < 0.001). Controlling for fatigue, depression, and anxiety, better attention function was associated with a greater likelihood of exercise in the past 3 months (p = 0.039), which in turn was associated with a lower BMI (p < 0.001).Conclusions The significant association between attention function and physical activity, if confirmed in a longitudinal study, will provide new targets for interventions aimed at improving physical activity and decreasing BMI among BCS.
    Psycho-Oncology 03/2015; 24(3). DOI:10.1002/pon.3598 · 4.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The number of breast cancer survivors increases every year, thanks to the development of new treatments and screening techniques. However, patients present with numerous side effects that may affect their quality of life. Exercise has been demonstrated to reduce some of these side effects, but in spite of this, few breast cancer patients know and follow the exercise recommendations needed to remain healthy. In this review, we describe the different breast cancer treatments and the related side effects and implications of exercise in relation to these. We propose that exercise could be an integrative complementary intervention to improve physiological, physical and psychological factors that affect survival and quality of life of these patients. For that reason, the main objective of this review is to provide a general overview of exercise benefits in breast cancer patients and recommendations of how to design exercise interventions in patients with different side effects.
    Clinical and Translational Oncology 06/2014; 17(3). DOI:10.1007/s12094-014-1184-8 · 1.60 Impact Factor