[Show abstract][Hide abstract] ABSTRACT: Little is known about the effect of different lifestyle interventions on sleep disturbances among sedentary obese or overweight persons. We randomized men and women aged 35–65 to 6 months of a weight loss diet (D); or D combined with supervised exercise training (D+E). Measurements were self-reported sleep disturbances, the Profile of Mood States questionnaire, BMI, total abdominal subcutaneous and visceral fat by magnetic resonance imaging, and aerobic fitness expressed as VO2peak. The groups did not differ in changes for body weight, abdominal total fat, VO2peak, and sleep disturbances. The novel finding herein is that reduced abdominal subcutaneous fat and depressive symptoms, with either D or D+E, were associated with less sleep disturbances.
Full-text · Article · Sep 2015 · Behavioral Sleep Medicine
[Show abstract][Hide abstract] ABSTRACT: To determine the association of lean vs fat mass with fitness in healthy, overweight and obese African Americans from families with early-onset coronary disease.
191 healthy, overweight, sedentary African Americans (69% women; aged 44.8 ± 11 years; body mass index 34 ± 5 kg/m2).
Anthropometrics, smoking, blood pressure, lipids, c-reactive protein, and glucose were assessed with standard methods; body composition was determined by dual energy X-ray absorptiometry; cardiorespiratory fitness was expressed as VO(2peak) attained during a maximal treadmill test.
In both men and women, greater lean mass was independently associated with higher VO(2peak) (P < .05) and explained > 21% of the variance in VO(2peak), adjusted for body mass index, fat mass, important covariables, and nonindependence of families.
In this cross-sectional study, lean mass was the key determinant of cardiorespiratory fitness, independent of sex, age, and magnitude of obesity. These data provide a strong rationale for examining whether interventions that increase lean mass may also improve fitness, even among high-risk overweight and obese African Americans.
No preview · Article · Jun 2015 · Ethnicity & disease
[Show abstract][Hide abstract] ABSTRACT: To examine whether a subjective measure of moderate-intensity exercise (12-13 on Borg's ratings of perceived exertion scale; RPE) corresponds to the target heart rate for moderate-intensity exercise (40-59% heart rate reserve; %HRR) and to determine the characteristics of those for whom RPE does not appropriately estimate exercise intensity.
3582 individuals with type 2 diabetes (age: 58.3±6.8 years; BMI: 35.9±5.9 kg/m(2)) underwent a maximal exercise test and minute-by-minute HR and RPE were recorded. Linear regression was used to determine the %HRR corresponding to an RPE of 12 and 13 for each individual.
At an RPE of 12 or 13, 57% of participants fell within the target 40-59%HRR range, while 37% and 6% fell above and below this range, respectively. Participants with a %HRR ≥60% (above range) were more likely to be female (OR: 1.19; 95% CI: 1.01,1.40), African American (OR: 1.65; 95% CI: 1.35, 2.02) or Hispanic (OR: 1.57; 95% CI: 1.27, 1.95), have a higher BMI (OR: 1.03; 95% CI 1.01, 1.04) and HRmax (OR: 1.02; 95% CI: 1.01, 1.02), and lower fitness (OR: 0.90; 95% CI: 0.85, 0.94) and RPEmax (OR: 0.68; 95% CI: 0.63, 0.73), compared to those within the target 40-59%HRR range (p-values'<0.05).
RPE appropriately gauges exercise intensity in approximately half of overweight individuals with type 2 diabetes; however, more than one-third of participants were at an increased risk of exercising at a higher than prescribed intensity when using RPE. Future studies should continue to examine the characteristics of individuals for whom RPE appropriately estimates exercise intensity and for those whom it does not.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Obstructive sleep apnea (OSA) is prevalent among older individuals and is linked to increased cardiovascular disease morbidity. This study examined the change in OSA severity after exercise training and dietary-induced weight loss in older adults and the association of the changes in OSA severity, body composition, and aerobic capacity with arterial distensibility.
Obese adults (n = 25) with OSA, age 60 yr or older, were instructed to participate in supervised exercise (3 d·wk) and follow a calorie-restricted diet. Baseline assessments of OSA parameters, body weight and composition, aerobic capacity, and arterial distensibility were repeated at 12 wk.
Nineteen participants completed the intervention. At 12 wk, there were reductions in body weight (-9%) and percentage of total body fat (-5%) and trunk fat (-8%) whereas aerobic capacity improved by 20% (all P < 0.01). The apnea-hypopnea index decreased by 10 events per hour (P < 0.01) and nocturnal SaO2 (mean SaO2) improved from 94.9% at baseline to 95.2% after intervention (P = 0.01). Arterial distensibility for the group was not different from that at baseline (P = 0.99), yet individual changes in distensibility were associated with the change in nocturnal desaturations (r = -0.49, P = 0.03) but not with the change in body weight, apnea-hypopnea index, or aerobic capacity.
The severity of OSA was reduced after an exercise and weight loss program among older adults, suggesting that this lifestyle approach may be an effective first-line nonsurgical and nonpharmacological treatment for older patients with OSA.
Full-text · Article · May 2014 · Medicine & Science in Sports & Exercise
[Show abstract][Hide abstract] ABSTRACT: Background:
The established interventions for weight loss are resource intensive which can create barriers for full participation and ultimate translation. The major goal of this pilot study was to evaluate the feasibility, acceptability, and preliminary efficacy of theoretically based behavioral interventions delivered by smartphone technology.
The study randomized 68 obese adults to receive one of four interventions for six months: (1) intensive counseling intervention, (2) intensive counseling plus smartphone intervention, (3) a less intensive counseling plus smartphone intervention, and (4) smartphone intervention only. The outcome measures of weight, BMI, waist circumference, and self-reported dietary intake and physical activity were assessed at baseline and six months.
The sample was 78% female and 49% African American, with an average age of 45 years, and average BMI of 34.3 kg/m(2). There were trends for differences in weight loss among the four intervention groups. Participants in the intensive counseling plus self-monitoring smartphone group and less intensive counseling plus self-monitoring smartphone group tended to lose more weight than other groups (5.4 kg and 3.3 kg, resp.).
The results of this pilot trial of a weight loss intervention provide preliminary support for using a smartphone application for self-monitoring as an adjunct to behavioral counseling.
Full-text · Article · Dec 2013 · Journal of obesity
[Show abstract][Hide abstract] ABSTRACT: To examine the effect of exercise on abdominal adipose tissue in adults with and without type 2 diabetes mellitus (T2DM).
Post hoc analysis of two randomised controlled trials.
Outpatient secondary prevention programme in Baltimore, Maryland, USA.
97 men and women with prehypertension, stage 1 or medically controlled hypertension. 49% of the sample was also diagnosed with T2DM.
All participants completed a 26-week (6.5 months) supervised aerobic and resistance exercise programme following American College of Sports Medicine guidelines.
The main outcomes in this post hoc analysis were total abdominal adipose tissue (TAT), subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) measured by MRI. Secondary outcomes were to determine whether the magnitude of abdominal fat change differed by diabetes status in men and women and to identify the predictors of change in abdominal fat distribution with exercise.
Overall, participants (mean age 61±6 years; 45% women) significantly improved peak oxygen uptake by 15% (p<0.01) and reduced weight by 2% (p<0.01). No change in SAT was observed after training. The reduction in VAT following exercise was attenuated in participants with T2DM (-3%) compared with participants who were non-T2DM (-18%, p<0.001 for the difference in change). The magnitude of VAT loss was associated with a decrease in body weight (r=0.50, p<0.001). After adjustment for weight change using regression analysis, diabetes status remained an independent predictor of the change in VAT.
Although participants with and without T2DM attained an exercise training effect as evidenced by increased fitness, VAT was unchanged in T2DM compared to those without T2DM, suggesting that these individuals may be resistant to this important benefit of exercise. The strategies for reducing cardiovascular disease risk in T2DM may be most effective when they include a weight loss component.
Clinicaltrials.gov Registry NCT00212303.
[Show abstract][Hide abstract] ABSTRACT: Though being physically active has associated with a healthier ankle-brachial index (ABI) in observational studies, ABI usually does not change with exercise training in patients with peripheral artery disease (PAD). Less is known about the effect of exercise training on ABI in patients without PAD but at high risk due to the presence of type 2 diabetes (T2DM).
Participants (n = 140) with uncomplicated T2DM, and without known cardiovascular disease or PAD, aged 40-65 years, were randomized to supervised aerobic and resistance training 3 times per week for 6 months or to a usual care control group. ABI was measured before and after the intervention.
Baseline ABI was 1.02 ± 0.02 in exercisers and 1.03 ± 0.01 in controls (p = 0.57). At 6 months, exercisers vs. controls improved ABI by 0.04 ± 0.02 vs. -0.03 ± 0.02 (p = 0.001). This change was driven by an increase in ankle pressures (p < 0.01) with no change in brachial pressures (p = 0.747). In subgroup analysis, ABI increased in exercisers vs. controls among those with baseline ABI <1.0 (0.14 ± 0.03 vs. 0.02 ± 0.02, p = 0.004), but not in those with a baseline ABI ≥1.0 (p = 0.085). The prevalence of ABI between 1.0 and 1.3 increased from 63% to 78% in exercisers and decreased from 62% to 53% in controls. Increased ABI correlated with decreased HbA1c, systolic and diastolic blood pressure, but the effect of exercise on ABI change remained significant after adjustment for these changes (β = 0.061, p = 0.004).
These data suggest a possible role for exercise training in the prevention or delay of PAD in T2DM, particularly among those starting with an ABI <1.0. Clinicaltrials.gov Registry Number: NCT00212303.
[Show abstract][Hide abstract] ABSTRACT: Recent data suggests possible net transport of urinary constituents across mammalian urinary tract epithelia (urothelia). To evaluate the effect of animal hydration status on such transport we instilled urine collected during two day water-deprivation, water-loading or ad-libitum water intake into isolated in-situ bladder(s) of groups of rats undergoing one of the same three hydration states. After 1 hour bladder dwell we retrieved the urine and measured differences in volume and solute concentration between instilled and retrieved urine. We previously reported results regarding changes in urine volume and net urea and creatinine transport and herein report the results of net urinary sodium, potassium, and chloride transport in the same animals. During water-loading conditions, urinary concentrations of Na, K, and Cl rose 4.9 mEq/L (30.7%), 2.6 mEq/L (16.5%), and 6.0 mEq/L (26.8%) respectively - indicating urothelial secretion into urine. During ad-libitum water intake urinary K and Cl concentrations fell 33.6 mEq/L (14.8%) and 28.4 mEq/L (12%) respectively (Na did not change) and during water deprivation urine Na, K and Cl concentrations fell dramatically by 53.2 mEq/L (18.6%), 159.4 mEq/L (34.6%) and 133.7 mEq/L (33.8%) - reflecting urothelial reabsorption of each ion. For each ionic species two factors independently influenced transport - the instilled urinary ion concentration, and the animal hydration state. These results demonstrate significant regulated ion transport across mammalian urothelia, support the notion that lower urinary tract modifies final urine, and suggest that the lower urinary tract may play a role in local and whole animal solute homeostasis.
Preview · Article · Aug 2013 · AJP Renal Physiology
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Exercise use among patients with cancer has been shown to have many benefits and few notable risks. The purpose of this study was to evaluate the impact of a home-based walking intervention during cancer treatment on sleep quality, emotional distress, and fatigue. METHODS: A total of 138 patients with prostate (55.6%), breast (32.5%), and other solid tumors (11.9%) were randomized to a home-based walking intervention or usual care. Exercise dose was assessed using a five-item subscale of the Cooper Aerobics Center Longitudinal Study Physical Activity Questionnaire. Primary outcomes of sleep quality, distress, and fatigue were compared between the two study arms. RESULTS: The exercise group (n = 68) reported more vigor (p = .03) than control group participants (n = 58). In dose response models, greater participation in aerobic exercise was associated with 11% less fatigue (p < .001), 7.5% more vigor (p = .001), and 3% less emotional distress (p = .03), after controlling for intervention group assignment, age, and baseline exercise and fatigue levels. CONCLUSION: Patients who exercised during cancer treatment experienced less emotional distress than those who were less active. Increasing exercise was also associated with less fatigue and more vigor. Home-based walking is a simple, sustainable strategy that may be helpful in improving a number of symptoms encountered by patients undergoing active treatment for cancer.
[Show abstract][Hide abstract] ABSTRACT: The benefits of regular physical activity are particularly salient to persons with serious mental illness (SMI) who have increased prevalence of obesity, diabetes, and earlier mortality from cardiovascular disease.
The Activating Consumers to Exercise through Peer Support (ACE) trial will examine the effectiveness of peer support on adherence to a 4-month pilot exercise program for adults with SMI. Design, rationale and baseline data are reported. Baseline measures included: graded treadmill test; six-minute walk; height, weight and blood pressure; body composition; fasting blood; and self-reported psychiatric symptoms. Fitness levels were compared with national data and relationships among fitness parameters, psychological factors and cardiovascular disease risk factors were examined.
There were 93 participants and 18 peer leaders recruited from community psychiatry programs with an average age of 47 years (SD 10). There were no differences in demographics (76% female, 72% African American) or mental health symptoms between participants and peer leaders. Ninety-five percent of the sample had below average fitness levels for their age and sex with average MET levels of 5.9(SD 2.2) for participants and 6.2(SD 2.3) for peer leaders. Fitness evaluated during the treadmill test and the six-minute-walk were associated (rs = 0.36, p<.001). Lower MET levels were associated with a higher BMI (rs = -0.35, p<.001) and percent body fat (rs = -0.36, p <.001).
The uniformly low baseline cardiovascular fitness and the association of fitness with BMI and adiposity underscore the importance of suitably tailored programs to increase physical activity among adults with SMI.
No preview · Article · Dec 2012 · Mental Health and Physical Activity
[Show abstract][Hide abstract] ABSTRACT: The primary aims of this paper were (1) to evaluate the influence of intensive lifestyle weight loss and exercise intervention (ILI) compared with diabetes support and education (DSE) upon Heart Rate Recovery (HRR) from graded exercise testing (GXT) and (2) to determine the independent and combined effects of weight loss and fitness changes upon HRR. In 4503 participants (45-76 years) who completed 1 year of intervention, HRR was measured after a submaximal GXT to compare the influence of (ILI) with (DSE) upon HRR. Participants assigned to ILI lost an average 8.6% of their initial weight versus 0.7% in DSE group (P < 0.001) while mean fitness increased in ILI by 20.9% versus 5.8% in DSE (P < 0.001). At Year 1, all exercise and HRR variables in ILI improved (P < 0.0001) versus DSE: heart rate (HR) at rest was lower (72.8 ± 11.4 versus 77.7 ± 11.7 b/min), HR range was greater (57.7 ± 12.1 versus 53.1 ± 12.4 b/min), HR at 2 minutes was lower (89.3 ± 21.8 versus 93.0 ± 12.1 b/min), and HRR was greater (41.25 ± 22.0 versus 37.8 ± 12.5 b/min). Weight loss and fitness gain produced significant separate and independent improvements in HRR.
Full-text · Article · Nov 2012 · Journal of obesity
[Show abstract][Hide abstract] ABSTRACT: Purpose:
To develop a video that provides accessible and usable information about the importance of physical activity to type 2 diabetes self-management and ways of incorporating physical activity into everyday life.
A 15-minute physical activity educational video narrated by US Surgeon General Dr Regina Benjamin was developed and evaluated. The video addresses the following topics: the effects of exercise on diabetes, preparations for beginning physical activity, types of physical activity, safety considerations (eg, awareness of symptoms of hypoglycemia during activity), and goal setting. Two patient screening groups were held for evaluation and revision of the video. Patient satisfaction ratings ranged 4.6 to 4.9 out of a possible 5.0 on dimensions of overall satisfaction, how informative they found the video to be, how well the video held their interest and attention, how easy the video was to understand, and how easy the video was to see and hear. Patients reported the educational video effective in empowering them to take strides toward increasing and maintaining physical activity in their lives. The tool is currently used in a clinical research trial, Project DECIDE, as one component of a diabetes and cardiovascular disease self-management program.
Full-text · Article · Oct 2012 · The Diabetes Educator
[Show abstract][Hide abstract] ABSTRACT: Background:
Because lifestyle-induced improvements in cardiovascular risk factors vary substantially across individuals with type 2 diabetes, we investigated the extent to which increases in fitness explain cardiovascular risk factor improvements independent of weight loss in a lifestyle intervention.
We studied 1-year changes in Look AHEAD, a randomized trial comparing an intensive lifestyle intervention (ILI) to a diabetes support and education (DSE) control group in adults with type 2 diabetes. Assessments included weight, fitness, blood pressure (BP), glucose, HbA1c, and lipids. We evaluated the effects of changes in weight and fitness on changes in cardiovascular risk factors by study arm, using R (2) from multiple linear regression.
Analyses included participants with fitness data at baseline and 1-year (n = 4408; 41% male, 36% non-white; mean age 58.7 ± 6.8 years). Weight change alone improved R (2) for explaining changes in risk factors up to 8.2% in ILI and 1.7% in DSE. Fitness change alone improved R (2) up to 3.9% in ILI and 0.8% in DSE. After adjusting for weight change, fitness was independently associated (p < 0.05) with improvements in R (2) for glucose (+0.7%), HbA1c (+1.1%), high-density lipoprotein (HDL) cholesterol (+0.4%), and triglycerides (+0.2%) in ILI and diastolic BP (+0.3%), glucose (+0.3%), HbA1c (+0.4%), and triglycerides (+0.1%) in DSE. Taken together, weight and fitness changes explained from 0.1-9.3% of the variability in cardiovascular risk factor changes.
Increased fitness explained statistically significant but small improvements in several cardiovascular risk factors beyond weight loss. Further research identifying other factors that explain cardiovascular risk factor change is needed.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
While the benefits of exercise in people with type 2 diabetes mellitus is well-known, knowledge of factors associated with dropouts of exercise intervention trials is limited. Examining clinical and psychosocial factors related to dropout is a necessary first step to developing an effective exercise program. We examined the predictors of a randomized trial of exercise intervention dropout among sedentary individuals with type 2 diabetes mellitus.
Participants (n = 140) were randomly allocated to a 6-month, 3 times per week exercise intervention, or to a control group. Psychological well-being was assessed using a 36-item Short Form Health Survey, the Profile of Mood States questionnaire, and an Exercise Self-Efficacy scale. Total percent body fat and abdominal subcutaneous and visceral fat were measured. Insulin resistance was assessed with the quantitative insulin sensitivity check index. Fitness was expressed as VO2 peak during treadmill testing.
There were significantly more dropouts in the exercise group than in the control group (r = 20.220; P < .01). Those who dropped out of the study had less exercise self-efficacy for lifting weight (r = 0.187; P < .05). Physiological parameters associated with dropouts included low fitness (r = 0.255; P < .01), higher insulin resistance (r = 0.167; P < .05), higher total percent body fat (r = 20.213; P < .05), and higher subcutaneous abdominal fat (r = 20.220; P < .05). In the multiple logistic regression model, exercise group assignment, insulin resistance, and fitness remained significant predictors of dropouts.
Special attention to the sedentary individuals with high insulin resistance and poor fitness should be incorporated into implementing exercise programs to improve diabetes treatment.
Full-text · Article · Sep 2012 · Journal of cardiopulmonary rehabilitation and prevention
[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of an exercise intervention on flow-mediated dilation (FMD) and circulating endothelial biomarkers in adults with type 2 diabetes (T2DM).
Sedentary adults (n = 140), aged 40-65, with T2DM and untreated pre or Stage I hypertension or treated hypertension were randomized to a 6-month, supervised, exercise program (3× week) or a sedentary control. Assessments included BMI, body and visceral fat, blood pressure, lipids, HbA1c, insulin sensitivity (QUICKI), fitness, FMD, E-selectin, P-selectin, intracellular and vascular cellular adhesion molecules (ICAM, VCAM), and tissue plasminogen activator (tPA). Intervention effects were compared by t-tests. Pearson's correlations were calculated between changes in cardiovascular risk factors and endothelial outcomes.
Exercisers significantly improved BMI (-0.6 kg/m(2)), body fat % (-1.4%), HbA1c (-0.5%), and fitness (2.9 mL/kg min) vs. controls (p < 0.05). However, there were no differences between groups in changes in FMD, E-selectin, P-selectin, ICAM, VCAM, or tPA. Among exercisers, changes in cardiovascular risk factors correlated with several biomarkers. Decreased P-selectin correlated with decreased BMI (r = 0.29, p = 0.04) and increased HDL cholesterol (r = -0.36, p = 0.01). Decreased ICAM correlated with decreased triglycerides and HbA1c (r = 0.30, p = 0.04; r = 0.31, p = 0.03) and increased QUICKI (r = - 0.28, p = 0.05). Decreased tPA correlated with decreased total body and visceral fat (r = 0.28, p = 0.05; r = 0.38, p = 0.008) and increased QUICKI (r = -0.38, p = 0.007).
While exercise resulted in improved fitness, body composition, and glycemic control, there were no changes in FMD or circulating endothelial biomarkers. The associations of changes in cardiovascular risk factors and endothelial biomarkers suggest that improvement in risk factors could mediate the exercise-induced improvements in endothelial function seen in prior studies.
[Show abstract][Hide abstract] ABSTRACT: Recent evidence suggests that regulated solute transport occurs across mammalian lower urinary tract epithelia (urothelia). To study the effects of dietary protein on net urothelial transport of urea, creatinine, and water, we used an in vivo rat bladder model designed to mimic physiological conditions. We placed groups of rats on 3-wk diets differing only by protein content (40, 18, 6, and 2%) and instilled 0.3 ml of collected urine in the isolated bladder of anesthetized rats. After 1 h dwell, retrieved urine volumes were unchanged, but mean urea nitrogen (UN) and creatinine concentrations fell 17 and 4%, respectively, indicating transurothelial urea and creatinine reabsorption. The fall in UN (but not creatinine) concentration was greatest in high protein (40%) rats, 584 mg/dl, and progressively less in rats receiving lower protein content: 18% diet, 224 mg/dl; 6% diet, 135 mg/dl; and 2% diet, 87 mg/dl. The quantity of urea reabsorbed was directly related to a urine factor, likely the concentration of urea in the instilled urine. In contrast, the percentage of instilled urea reabsorbed was greater in the two dietary groups receiving the lowest protein (26 and 23%) than in those receiving higher protein (11 and 9%), suggesting the possibility that a bladder/urothelial factor, also affected by dietary protein, may have altered bladder permeability. These findings demonstrate significant regulated urea transport across the urothelium, resulting in alteration of urine excreted by the kidneys, and add to the growing evidence that the lower urinary tract may play an unappreciated role in mammalian solute homeostasis.
[Show abstract][Hide abstract] ABSTRACT: Increased blood pressure (BP) in type 2 diabetes (T2DM) markedly increases cardiovascular disease morbidity and mortality risk compared to having increased BP alone.
To investigate whether exercise reduces suboptimal levels of untreated suboptimal BP or treated hypertension.
Prospective, randomized controlled trial for 6 months.
Single center in Baltimore, MD, USA.
140 participants with T2DM not requiring insulin and untreated SBP of 120-159 or DBP of 85-99 mmHg, or, if being treated for hypertension, any SBP <159 mmHg or DBP < 99 mmHg; 114 completed the study.
Supervised exercise, 3 times per week for 6 months compared with general advice about physical activity.
Resting SBP and DBP (primary outcome); diabetes status, arterial stiffness assessed as carotid-femoral pulse-wave velocity (PWV), body composition and fitness (secondary outcomes).
Overall baseline BP was 126.8 ± 13.5 / 71.7 ± 9.0 mmHg, with no group differences. At 6 months, BP was unchanged from baseline in either group, BP 125.8 ± 13.2 / 70.7 ± 8.8 mmHg in controls; and 126.0 ± 14.2 / 70.3 ± 9.0 mmHg in exercisers, despite attaining a training effects as evidenced by increased aerobic and strength fitness and lean mass and reduced fat mass (all p < 0.05), Overall baseline PWV was 959.9 ± 333.1 cm/s, with no group difference. At 6-months, PWV did not change and was not different between group; exercisers, 923.7 ± 319.8 cm/s, 905.5 ± 344.7, controls.
A completion rate of 81 %.
Though exercisers improve fitness and body composition, there were no reductions in BP. The lack of change in arterial stiffness suggests a resistance to exercise-induced BP reduction in persons with T2DM.
No preview · Article · May 2012 · Journal of General Internal Medicine