Self-reported exercise and bone mineral density in prostate cancer patients receiving androgen deprivation therapy

Purpose: Men with prostate cancer receiving androgen deprivation therapy (ADT) are at increased risk for decreased bone mineral density (BMD). This study evaluates the relationship between self-reported daily activity, endurance and resistance exercise, and BMD measured by dual-energy x-ray absorptiometry (DEXA) in prostate cancer patients receiving ADT. Data sources: We recruited 96 men treated with ADT for >= 9 months from urology and cancer practices. The Canadian Fitness Survey assessed daily activity and exercise. Data on demographic and lifestyle characteristics and calcium and vitamin D supplementation were collected. Blood was collected for analysis of 25-OH vitamin D. A DEXA scan was performed. Conclusions: A positive association between endurance exercise and DEXA T-scores of the hip was shown. Regression analysis showed endurance exercise of medium to heavy intensity (measured as energy expenditure in METhours/week) was associated with T-scores of the hip (beta = 0.048; 95% CI 0.003, 0.112; p =.040) but not with spinal T-scores after controlling for age, body mass index, and alcohol use. Implications for practice: Findings are cross-sectional, but if confirmed in prospective studies suggest that increased endurance exercise is a practical measure nurse practitioners can institute to prevent low bone density in the hip of men treated with ADT.