The android:gynoid percent fat ratio (AGFR) is associated with increased risk of cardiovascular disease and type 2 diabetes in breast cancer survivors (BCS). Exercise reduces fat mass in BCS; however, few studies have focused on AGFR. The study purpose was to examine the effects of a 16-week aerobic and resistance exercise intervention on AGFR among BCS. We assessed whether exercise-induced changes in AGFR were associated with improved insulin resistance.
BCS (Stage I-III) were randomized to exercise (n = 50) or usual care (n = 50). The thrice weekly 16-week intervention included supervised, progressive moderate-vigorous aerobic and resistance exercise. AGFR was obtained from a whole-body dual-energy x-ray absorptiometry. Insulin resistance was estimated using homeostatic model assessment of insulin resistance (HOMA-IR) calculated from fasting insulin and glucose levels. Within and between group differences were assessed by paired t-test and repeated measures ANOVA. Pearson’s correlation was computed to assess the association between AGFR and HOMA-IR in the exercise group.
Participants were 53 ± 10.4 years old, overweight (BMI>25.0 kg/m2; 54%), Hispanic (63.1%), and had undergone a mastectomy (90%) and chemotherapy + radiation therapy (76%). Adherence to the intervention was 95% and post-intervention assessments were available on 91% of participants. Post-intervention, AGFR significantly decreased in the exercise group from baseline and when compared to usual care (p < 0.001). Post-intervention, strong correlations were found between AGFR and HOMA-IR (r = 0.95; p < 0.01).
A progressive aerobic and resistance exercise intervention is an effective strategy to decrease AGFR in BCS. BCS who experience exercise-induced improvements in AGFR may also experience improved insulin resistance thereby reducing the risk for comorbid conditions.
National Cancer Institute.
All authors have declared no conflicts of interest.