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

Abstract

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. 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. 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 MET-hours/week) was associated with T-scores of the hip (β = 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. 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.