Effects of a parallel-arm randomized controlled weight loss pilot study on biological and psychosocial parameters of overweight and obese breast cancer survivors.

BACKGROUND: Weight gain often occurs after breast cancer (BC) diagnosis and obesity along with sedentary behavior are associated with increased risk of BC recurrence and mortality. The primary objective of this study was to determine whether a significant weight loss, of approximately 10%, would lead to beneficial changes in biomarkers associated with cancer and/or cancer recurrence, and quality of life (QOL) in overweight and obese BC survivors. METHODS: This parallel-arm study took place in Minneapolis, Minnesota, from January 2009 until March 2010. Participants were overweight and obese postmenopausal BC survivors who had completed treatment at least 3 months prior to enrollment and who did not smoke. Twenty-one BC survivors were randomized, via a random number generator computer software, to a 1000-calorie deficit feeding and exercise intervention (CR) or a weight management counseling intervention (WM) for 12 weeks followed by a 6-week follow-up. Body weight, biomarkers, and QOL were measured at baseline, weeks 6, 12, and 18. Body composition and fitness level were measured at only two time points. RESULTS: Twenty-one women were enrolled into the study and 20 completed all time points. Weight loss occurred with both interventions. Body weight in CR changed from 85.5 (95% confidence interval (CI) 77, 94) kg to 76.7 (95% CI 68.1, 85.2) kg, whereas in WM it changed from 98.3 (95% CI 89.8, 106.8) kg to 93.2 (95% CI 84.6, 101.7) kg. Fitness in CR changed from 4.9 (95% CI 4, 5.8) to 6.3 (95% CI 5.4, 7.2). CR led to lower plasma levels of leptin, F2-isoprostanes, and CRP. Quality of life seemed to improve with both interventions, while sleep quality decreased only in CR. CONCLUSIONS: Overweight and obese BC survivors were able to adhere to a strict diet and exercise program, which significantly decreased body weight, increased fitness level, and improved biomarkers and QOL. However, the strict dietary intervention in CR seemed to decrease participants' sleep quality and social relationships. Future larger randomized controlled trials should focus on behavioral modification and personalized nutrition counseling to help breast cancer survivors achieve a sustainable weight loss and fitness level. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02940470.

Attrition and adherence of young women to aerobic exercise: lessons from the WISER study.

The purpose of this report is to identify factors associated with attrition and adherence of young women to a 16-week randomized aerobic exercise intervention on biomarkers associated with breast cancer risk. The exercise group was prescribed a progressive weight-bearing aerobic exercise program consisting of 30 minute workouts, 5 times/wk for 16 weeks. Adherence was calculated as the average minutes of exercise per week during participation in the study. Of the total of 212 women randomized into the exercise intervention 46 dropped out, of which 82.5% dropped out during the earlier stages of exercise suggesting that reasons for withdrawal may have been related to difficulties with initiating physical activity. Time commitment or lack of time was the primary reason for withdrawal. Drop outs reported lower physical activity at baseline than study completers (p=.0007). Although 78% of the 212 randomized participants completed the exercise intervention, only 4.7% of the participants exercised for at least 150 min/wk during the entire study period. Significant predictors of adherence were self-reported physical activity at baseline and depression scores. We conclude that predictors of adherence to exercise in our population of young women are similar to those reported for older adults. We also found that young women are more likely to exercise at moderate to vigorous intensity for 90 to 120 min rather than 150 min per week, even when participating in a highly structured exercise intervention.

Women in Steady Exercise Research (WISER): study design and methods.

PURPOSE: Observational studies have shown that physical activity is inversely associated with breast cancer etiology. WISER is a randomized controlled trial examining the effects of exercise training on oxidative stress, and hormonal and metabolic factors associated with breast cancer risk. METHOD: Subjects were recruited via emails, flyers, and mass media advertising. Inclusion criteria included: sedentary, age 18-30 years, non-smokers, BMI 18-40 kg/m2, not using any hormonal contraceptives. After completion of all baseline measures subjects were randomized into a control group or an exercise intervention for 4 menstrual cycles. The exercise group was asked to complete five 45 min exercise sessions per week. Exercise intensity was set at 65-70% of maximum age- predicted heart rate (max HR) and increased every four weeks. All women provided blood samples four times during the study for measurement of blood F2-isoprostanes, hormones and IGF-axis proteins. In addition, 24-hour urine samples were collected at baseline and follow-up for measurement of estrogen metabolites, as well as 24-hour food records to monitor participants' diets. DISCUSSION: WISER consented 683 women among which 391 enrolled and 319 successfully completed the study. The overall dropout rate was 18.4% (n=72) with a higher number of participants dropping from the exercise group (n=46). No differences were found between dropouts and completers with respect to age, body weight, BMI, and demographic characteristics with the exception of degree of education. Findings from this trial will be useful in understanding the physiologic mechanisms by which exercise possibly contributes to decreased breast cancer risk.

Bone volumetric density, geometry, and strength in female and male collegiate runners.

PURPOSE: To explore differences in tibial bone geometry, volumetric density, and estimates of bone strength in runners and healthy controls. METHODS: Male (n = 21) and female (n = 38) runners (49.1 +/- 13.2 miles x wk(-1)) and inactive healthy controls (17 males and 32 females; mean age = 22 +/- 3.3 yr) were recruited to participate. Peripheral quantitative computed tomography was used to assess total volumetric bone mineral density (vBMD, mg x mm(-3)), total bone area (ToA, mm2), and an estimate of compressive bone strength (bone strength index (BSI) = ToA x total bone volumetric density (ToD2)) at the distal (4%) site of the tibia. ToA (mm2) and cortical bone area (CoA, mm2), cortical vBMD (CoD, mg x mm(-3)), cortical thickness (CoTh, mm), and an estimate of bone bending strength (polar strength strain index (SSIp), mm3) were measured at 50% and 66% sites. RESULTS: ToA and BSI were significantly greater (+11%-19%, P < 0.05) in female runners than controls at the 4% site. At the proximal sites, female runners had significantly greater ToA, CoA, CoTh, and SSIp (+9%-19%, all P < 0.001) compared with female controls. vBMD was similar at all tibia sites. Compared with controls, male runners had significantly greater CoTh at the 50% and 66% sites (+8% and 14%, respectively, P < 0.05) as well as greater CoA (+11%, P < 0.009) at the 66% site. There were no differences in bone strength or density at any site in the male runners. CONCLUSIONS: Greater bone strength in female runners was attributable to greater bone area rather than density. Although male runners did not show greater bone strength, they did exhibit favorable bone geometric properties. These data further document that running has osteogenic potential.

Purposeful exercise and lifestyle physical activity in the lives of young adult women: findings from a diary study.

It is important to know how physical activity is incorporated in women's lives to assess ways they can feasibly attain and maintain lifelong healthy practices. This study aimed to determine whether patterns of activity differed among young women whose physical activity met nationally recommended levels from those who did not. The sample was 42 women (aged 18-30 years) who had completed an exercise intervention (22 from the exercise group, 20 from the control group). Participants recorded pedometer steps and physical activities in diaries including form, duration and perceived exertion during 12 randomly assigned weeks over 26 weeks. We divided the sample into quartiles of moderate to vigorous physical activity to examine the composition of physical activities per quartile. Walking and shopping comprised the majority of physical activity in the lowest quartile of moderate to vigorous physical activity. In the second and third quartiles, walking and household/childcare together comprised more than two-thirds of all activities. Only in the highest quartile was cardio activity (not including walking, shopping and household/childcare) the largest proportion of activity; this category stood alone as varying significantly across quartiles of moderate to vigorous physical activity (p < 0.005). Among these young adult women, self-reported "lifestyle" physical activity was not sufficient to meet recommended levels of moderate to vigorous physical activity. The one-quarter who met recommended levels of moderate to vigorous physical activity did so largely through purposeful physical activities directly associated with exercise. Further research is needed to refine means of more fully measuring physical activities that women frequently perform, with particular attention to household work, childcare and shopping and to differing combinations of activities and levels of exertion by which diverse women can meet the recommended levels. The findings of this small scale study reinforce the ongoing benefit of recommending structured, planned physical activity at moderate and vigorous levels of intensity to young, healthy women to ensure they obtain the health benefits.