FP783LOW SERUM TESTOSTERONE LEVELS IN MALE HEMODIALYSIS PATIENTS ASSOCIATE WITH REDUCED PHYSICAL ACTIVITY AND IMPAIRED BODY COMPOSITION

Abstract

Introduction and Aims: Chronic kidney disease (CKD) associates with alterations in body homeostasis and metabolic derangements including hormone secretion disorders. In male CKD patients, hypogonadism represented by testosterone deficiency is common and associates with various complications including increased mortality. Here we evaluated relations of circulating testosterone levels with body composition and physical activity in male hemodialysis (HD) patients. Methods: In a cross-sectional study including 58 male prevalent HD patients, baseline testosterone and nutritional and biochemical parameters of inflammation were measured. Body composition was assessed by bioelectrical impedance analysis. Physical activity was assessed by the use of pedometers, and the number of steps per day was recorded. Patients with testosterone below the normal range established in our laboratory (reference value 241-827 ng/dl) were classified as being hypogonadal. Results: Mean testosterone level was 329 ± 157 ng/dl; 20 patients (35%) had testosterone levels below the normal range. These hypogonadal patients had reduced physical activity compared with the other patients [2753 ± 1789 steps/day compared to 4169 ± 3251 (p=0.055)]. Additionally, patients in the hypogonadism group presented higher percentage of fat body mass (39% vs. 36%; p=0.035) and lower percentage of lean body mass (44% vs. 48%, p=0.040). Testosterone levels associated with lean body mass independent of age. However, in multivariate analysis, this relation between lean body mass and testosterone ceased to be significant when physical activity was included. Conclusions: There is a high prevalence of hypogonadism in the male hemodialysis population. For the first time we show that lower testosterone levels are associated with reduced levels of physical activity. Probably the relationship between testosterone and physical activity goes through the connection between testosterone and muscle mass with lower levels of testosterone being associated with impaired body composition characterized by a lower percentage of lean body mass and a higher percentage of fat body mass.