A pilot randomized controlled trial of a commercial diet and exercise weight loss program in minority breast cancer survivors

Abstract

Objective Obesity is associated with poorer breast cancer outcomes and losing weight postdiagnosis may improve survival. As Hispanic and black women have poorer breast cancer prognosis than non-Hispanic whites diagnosed at similar age and stage, and have higher rates of obesity, effective weight loss strategies are needed. We piloted a randomized, waitlist-controlled, crossover study to examine the effects and feasibility of the commercial Curves weight loss program among Hispanic, African American and Afro-Caribbean breast cancer survivors. Design and Methods Women with stage 0– IIIa breast cancer ≥6 months posttreatment, sedentary, and BMI ≥25 kg/m2 were randomized to the immediate arm (IA): 6 months of the Curves program followed by 6 months of observation; or the waitlist control arm (WCA): 6 months of observation followed by 6 months of the Curves program. The Curves program uses a 30-min exercise circuit and a high-vegetable/low-fat/calorie-restricted diet. Results A total of 42 women enrolled (79% Hispanic, 21% black), mean age 51 (range 32–69) and mean BMI 33.2(±5.9) kg/m2; 91% were retained at month 12. At month 6, women in the IA lost an average 3.3% (±3.5%) of body weight (range: 1.7% gain to 10.6% loss), as compared with 1.8% (±2.9%) weight loss in the WCA (P = 0.04). At month 12, on average women in the IA regained some but not all of the weight lost during the first 6 months (P = 0.02). Conclusions Minority breast cancer survivors were recruited and retained in a weight loss study. Six months of the Curves program resulted in moderate weight loss, but weight loss was not maintained postintervention. Future interventions should identify methods to increase uptake and maintenance of weight loss behaviors.

Dietary Modifications, Weight Loss, and Changes in Metabolic Markers Affect Global DNA Methylation in Hispanic, African American, and Afro-Caribbean Breast Cancer Survivors,

“…In this study, we evaluated 6-and 12-mo changes in global DNA methylation in Hispanic, African American, and Afro-Caribbean breast cancer survivors who were part of a larger study examining the effects of a specific dietary change and physical activity weight loss program among sedentary and overweight/ obese minority breast cancer survivors (28). A decrease in percentage of body fat, an increase in plasma glucose concentrations, and changes in diet were associated with changes in global markers of DNA methylation.…”

“…The intervention has been described in detail elsewhere (28). Briefly, the 6-mo weight loss program encouraged increasing physical activity to 90 min/wk, reducing caloric intake (1200 kcal/d for 1-2 wk, followed by 1600 kcal/d), and distributing caloric intake as 45% protein/30% carbohydrates/25% fat.…”

“…Given the modest changes in health behaviors and metabolic markers in both arms of the parent study (28), and the relatively small number of women for whom baseline and follow-up buffy coat samples were available (n = 24), participant data were analyzed as a cohort. Paired t tests were performed to compare the baseline values to 6-and 12-mo values for anthropometric measures, health behaviors, metabolic biomarkers, and DNA methylation measures.…”

“…Analyses used data and blood samples from breast cancer survivors who participated in the parent weight loss intervention trial, which has been described elsewhere (28). Briefly, a group of 42 minority breast cancer survivors participated in a randomized, crossover, waitlist-controlled pilot and feasibility study to test the effects of a 6-mo weight loss program using physical activity and dietary change.…”

“…In this study, we used anthropometric measures, health behavior measures, and blood samples collected in a pilot study of a dietary change and physical activity weight loss intervention among overweight and sedentary minority breast cancer survivors (28). We conducted hypothesis-generating analyses to assess the associations between changes in anthropometric measures, metabolic biomarkers, diet, and physical activity with changes in 3 separate measures of DNA methylation that have previously been associated with environmental and behavioral exposures: global concentrations of DNA methylation measured by LUMA and concentrations of DNA methylation at the repeated sequences LINE-1 and satellite 2 (Sat2).…”