Metabolic syndrome is associated with increased risk of cardiovascular disease, type 2 diabetes, and possibly cancer recurrence, and its occurrence is higher in breast cancer survivors than age-matched postmenopausal women. Now, a study on exercise has found that aerobic and resistance exercise intervention reduced metabolic syndrome in sedentary, overweight, and obese Hispanic breast cancer survivors. U.S. researchers presented their findings during a poster session on Friday, December 8, at the San Antonio Breast Cancer Symposium.
This preplanned subanalysis included 60 sedentary Hispanic breast cancer survivors (body mass index greater than 25 kg/m2) from the researchers’ larger metabolic syndrome trial. Hispanic breast cancer survivors were randomized to the exercise intervention ([EXE], n = 30) or usual care ([UC], n = 30). The EXE group participated in three supervised exercise sessions per week for 16 weeks. Aerobic exercise was performed at 65%–85% heart rate maximum for approximately 30 minutes. Resistance exercise was performed in circuit-fashion with three sets of 10–15 repetitions, including upper and lower body exercises at 65%–85% one-repetition maximum. The UC group was asked not to increase their current exercise levels during the study period. Participants were tested for metabolic syndrome (i.e., blood pressure, waist circumference, fasting blood glucose, high-density lipoprotein cholesterol, and triglycerides) at baseline, within one week following the 16-week study period, and at 12 weeks follow-up for the EXE group only.
At baseline, 82% (overall and by group) of the Hispanic breast cancer survivors met the criteria for metabolic syndrome. No significant group differences were found between the EXE and UC groups at baseline (p > 0.01). Postintervention, all metabolic syndrome components were significantly lower in the EXE group than the UC group (p < 0.01) and only 15% of participants in the EXE group met the criteria for metabolic syndrome, representing a 67% absolute decrease. This is in comparison to 84% of participants in the UC group. Body fat mass decreased by 10% during the 16-week EXE period, compared to a 2% increase in the UC group (p < 0.01). Metabolic syndrome changes remained significantly improved in the EXE group when fat mass was included as a covariate in the statistical model. At the follow-up assessment in the EXE group, all metabolic syndrome variables remained significantly improved compared to baseline (p < 0.01) and were not significantly different postintervention (p > 0.25) despite slight increases (less than 2%) in waist circumference and triglyceride levels.
To date, this is one of only a few exercise trials in a minority group of breast cancer survivors, and findings suggest “the benefits of the intervention on metabolic syndrome were sustainable in the absence of a supervised intervention.”