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.
NCT01140282.
The authors.
National Cancer Institute.
All authors have declared no conflicts of interest.