Moderate-to-vigorous exercise achievable, beneficial for older, obese breast cancer survivors
ATLANTA — Older, sedentary, obese breast cancer survivors experienced favorable changes in body composition after a 3-month weight loss intervention that involved high volume moderate-to-vigorous physical activity, according to results of a study presented at American Association for Cancer Research Annual Meeting.
These changes included reductions in visceral adipose tissue and improvements in serum risk biomarkers, results showed.
“Body composition, adipose distribution and fitness are likely superior to BMI alone in predicting outcomes in obese breast cancer survivors,” Carol J. Fabian, MD, director of the breast cancer prevention center at University of Kansas Cancer Center, and colleagues wrote. “Visceral adipose tissue is thought to be disproportionately responsible for the metabolic and inflammatory changes linking obesity and breast cancer recurrence.”
Fabian and colleagues evaluated 18 breast cancer survivors (median age, 60 years), who participated in a 3-month behavioral weight loss intervention. The intervention included a modest reduction in calories (350-530 kcal/day) in combination with a YMCA membership and twice-weekly personal trainer sessions.
The researchers evaluated moderate-to-vigorous physical activity (40%-80% of heart rate reserve in older women) through Garmin Vivoactive smart watches linked to GarminConnect. Participants increased their total weekly activity from 100 minutes during week 1 to 300 minutes during week 9. More than 200 minutes per week of moderate-to-vigorous physical activity served as the goal.
Researchers assessed the women before and after the intervention, measuring peak oxygen consumption (VO2peak); body composition by dual X-ray absorptiometry (GE Lunar iDXA); and blood concentrations of adipokines, cytokines and hormones.
Eleven of the participants had previously undergone chemotherapy and 13 were receiving aromatase inhibitors.
At baseline, participants had median BMI of 37 kg/m2 (range, 31-43), median total mass of 95 kg (range, 76-125), median total fat of 46 kg (range, 34-66), and median visceral adipose tissue of 1.7 kg (range, 1-3). Except for one participant, all had baseline visceral adipose tissue levels consistent with increased risk for metabolic syndrome.
Seventeen of the 18 participants completed a minimum of 150 minutes per week of moderate-to-vigorous physical activity, with a median of 176 (range, 55-291) minutes per week for weeks 9 to 12.
Fitness — as represented by VO2peak — increased from 18.9 ml/kg/min (13.7-25.3) to 21.1 ml/kg/min (17.1-31.4), which was statistically significant (P = .0003; Wilcoxon signed rank test). Significant reductions had occurred at 3 months in total mass (median, 7%), fat mass (median 13%) and visceral adipose tissue (median 20%; range-1-41; P < .0003 for all).
The researchers also reported reductions in serum leptin, insulin and leptin/adiponectin ratio (P < .01). They noted a strong association between moderate-to-vigorous physical activity at weeks 9 to 12 and leptin/ adiponectin ratio (P = .001); less robust correlations were observed between moderate-to-vigorous physical activity during this period and visceral adipose tissue loss (P = .043).
“High volume moderate-to-vigorous physical activity can be achieved by older, sedentary, obese breast cancer survivors, and this translates to favorable modulation of body composition, including visceral adipose tissue measures and serum risk biomarkers,” Fabian and colleagues wrote. – by Jennifer Byrne
Fabian CJ, et al. Abstract 2425/1. Presented at: AACR Annual Meeting; March 29-April 3, 2019; Atlanta.
Disclosures: The authors report no relevant financial disclosures.