INTRODUCTION AND AIMS: Sex hormone binding globulin (SHBG) and testosterone have been associated with obesity and insulin resistance, particularly in women with polycystic ovary synrdome. The aim of the present study was to address the hypothesis that in males with end stage renal disease SHBG and testosterone serum levels may relate to insulin resistance, a well-known condition in uremia.
METHODS: In a cross-sectional study we enrolled all men treated with chronic hemodialysis in the University Hospital of Larissa. As control we used a community based group of healthy males matched for age and Body Mass Index (BMI). We assessed the BMI (kg/m2) from body weight and height, the body fat content (%) by bioelectrical impedance and the serum SHBG (nmol/L), testosterone (ng/ml) and estradiol (pg/ml) by standard methods. Testosterone < 3.25 ng/ml defined biochemical hypogonadism. In non-diabetic males, we calculated the homeostasis model assessment index (HOMA-R), an estimate of insulin resistance, from serum fasting insulin and glucose.
RESULTS: In all 27 men (age 54.4 ± 19 years) on chronic hemodialysis (treatment duration 29.1 ± 14.4 months) and 51 healthy men (age 47.1 ± 9.6 years) were enrolled in the study. In men on hemodialysis vs. healthy men there were significantly increased serum levels of SHBG (40.9 ± 26.9 vs. 27.6 ± 11.9 nmol/L; p=0.031) and frequency of biochemical hypogonadism (22.2 vs. 3.9 %; p=0.011). In addition, in cases without diabetes (n=22), a significant correlation was observed between serum SHBG levels on the one hand and the HOMA-R (r = -0.586, p=0.004) and the fasting insulin levels (r = -0.650, p=0.001) on the other (Figure). The significant relationship between the SHBG levels (nmol/L) and insulin resistance, i.e. the HOMA-R (mmol•μIU/ml), persisted in multiple regression analysis. Detailed findings of the multiple linear regression analysis are shown on the Table.
CONCLUSIONS: Our findings confirmed the enhanced prevalence of biochemical hypogonadism in males on chronic hemodialysis. The serum levels of SHBG, in cases with end stage kidney disease without diabetes mellitus, correlated with serum insulin and insulin resistance.
Comments