Resistance Training Improves Muscular Strength in Prostate Cancer Patients Undergoing Androgen Deprivation Therapy

Abstract

Prostate cancer (PC) patients treated with androgen deprivation therapy (ADT) are at risk for an increased rate of adipose tissue accumulation and skeletal muscle wasting, which may lead to reductions in muscular strength and ultimately functional decline and loss of independence. Resistance training that includes at least 2 sessions per week, targeting all major muscle groups, may offer one strategy to arrest these declines. PURPOSE: To examine i) changes in upper body (seated chest press) and a lower body (leg extension) muscular strength in older PC patients on ADT treatment and ii) the associations between age, time on treatment with ADT, muscular strength and body composition in 32 PC patients in the IDEA-P trial. METHODS: 32 PC patients were randomized to resistance training coupled with exercise and dietary counseling (16) or a standard care control group (16). The treatment group attended 2 sessions p/week of resistance training (supervised month 1&2, independent month 3). Muscular strength was assessed with a 1RM protocol for both upper (UB) and lower body (LB) at baseline and again after 2 and 3 months. Body composition (%BF) was measured with the BODpod, while time on treatment (TOT) was measured in months. RESULTS: At baseline PC patients were M=66±7.7 years of age, had been on ADT treatment for M=22 ±22 months and were obese according to their body composition (% Body fat M=38.2±9.1). At baseline, there were significant bivariate correlations between age, UB and LB muscular strength (r=-0.537, p=<0.01) (r=-0.392, p=<0.05) respectively. TOT was not associated with baseline scores but was associated with 2 month change in LB muscular strength. A 2 (treatment) x 3 (time) ANCOVA controlling for age revealed a significant treatment by time interaction for UB (F=6.721, p=<0.01) and LB (F=3.988, p=<0.05) strength. CONCLUSION: Resistance training is a safe and feasible means of improving and maintaining muscular strength in older men undergoing ADT for prostate cancer. Increases in muscular strength may protect aging PC patients against future declines in physical function. However, increasing adherence to home based exercise programs outside of supervised sessions is key to changing lifestyles and health outcomes for prostate cancer patients over the long term. Supported by NIH/NCI R03 CA16296901; 5R25 CA122061