The impact of androgen deprivation therapy on body composition and hepatic fat content among men with prostate cancer

Introduction & objectives Androgen deprivation therapy (ADT) has been associated with an increased prevalence of the metabolic syndrome (MetS), risk of type 2 diabetes mellitus and cardiovascular disease. Additionally an association between nonalcoholic fatty liver disease (NAFLD), the hepatic component of MetS, and low levels of testosterone (T) have been suggested, and recent studies have shown that induced hypogonadism primarily increase subcutaneous fat in healthy men. Therefore, we investigated the effect of ADT on body composition and fat distribution measured by gold standard MRI, and on components of MetS among men with prostate cancer. Materials & methods Hormone naive non-diabetic men with prostate cancer commencing ADT were prospectively included. Patients were evaluated at baseline and after 6 months. MRI measurements of visceral (VAT) and subcutaneous fat volume (SAT) were performed using the Achieva 3.0 T MR-imaging system (Philips Medical Systems, Best, the Netherlands). Hepatic fat fraction (HFF) was attained by MR spectroscopy. Results Thirty-one men with a mean age of 74 (+/-6) years and a mean BMI of 27.2 (+/-4.0) kg/m2 were included. All patients reached castration levels of T < 50 ng/dl measured at 3 and 6 months. SAT increased significantly by 12.5% (p=0.010) after 6 month of ADT. Increase in SAT was positively correlated to changes in BMI, hip and waist circumference (p< 0.05). Hip circumference increased by 1.1 cm (95% CI 0.1-2.0) (p=0.036), whereas waist circumference did not change. There was a trend towards an increase in median HFF from 0.5% (IQR 0.5-1.4) to 1.0% (IQR 0.5-1.8) (p=0.09) during ADT. The proportion of men with hepatic steatosis (HFF>5%) increased, non-significantly from 2/27 at baseline to 6/27 after 6 months (p=0.25). No change in VAT was apparent. Total-and HDL cholesterol increased significantly by 0.39 mmol/l (95% CI 0.21-0.55) and 0.18 mmol/l (0.09-0.26), respectively (p<0.001). No significant change was observed regarding BMI, systolic or diastolic blood pressure, LDL cholesterol, fasting and 2h post-glucose challenge plasma glucose, or HbA1c. Conclusion We did not find a significant increase in risk of the classical components of the MetS during ADT. However, measuring body composition using advanced MRI demonstrated an increase in subcutaneous fat and a non-significant tendency towards increased hepatic fat accumulation, with no change in VAT. Further investigations into the metabolic effects hereof are being conducted.