Body Composition Alterations, Energy Expenditure and Fat Oxidation in Elderly Males Suffering from Prostate Cancer, Pre and Post Orchiectomy

INTRODUCTION: Testosterone is needed for normal male development, muscle strength, bone mineralization, hematopoietic function, and sexual and reproductive functions. The main purpose of androgen deprivation therapy in prostate cancer is to reduce tumor progression, but therapy is often accompanied by significant adverse effects. OBJECTIVE: This study aimed to determine the effects of androgen deprivation therapy on body composition and resting metabolic rate in patients with prostate cancer. PATIENTS AND METHODS: A prospective study was performed to evaluate the body composition of 16 elderly males (aged 63–96; median age 71) with prostate cancer scheduled for orchiectomy, one year before and after surgery. Body composition was measured by DEXA, and energy expenditure, fat and carbohydrate oxidation were measured by indirect calorimetry. RESULTS: Body weight (p=0.01), lean mass (p=0.004), and lipid oxidation (p=0.001) decreased significantly. Carbohydrate oxidation (p=0.02), FSH (p=0.0001) and LH (p=0.0001) levels increased significantly. Changes in fat mass (p=0.06) and bone mineral density (p=0.48) were not significant. CONCLUSIONS: After 12 months of androgen deprivation therapy, elderly men with metastatic prostate cancer exhibit a decline in lean body mass and lipid oxidation, together with increased carbohydrate oxidation.