Urinary excretion of testosterone and estradiol in chinese men and relationships with serum lipoprotein concentrations

Abstract

Urinary excretion of total and free testosterone and estradiol was measured in 46 healthy Chinese men, along with serum concentrations of total testosterone and estradiol and the calculated free (unbound) concentrations. Associations with serum concentrations of total, low-density lipoprotein (LDL), high-density lipoprotein-2 (HDL 2), and HDL 3 cholesterol, apolipoproteins (apos) A-I and B, and lipoprotein(a) [Lp(a)] were studied. Serum total and free testosterone concentrations were positively correlated with HDL and HDL 2 cholesterol and apo A-I. Serum total and free estradiol levels showed borderline-significant negative associations with total and LDL cholesterol levels. Among urinary variables, total estradiol excretion was negatively associated with apo B levels and showed borderline-significant associations with total and LDL cholesterol. Adjustment for potential confounders, including age, body mass index (BMI), and waist to hip ratio (WHR), strengthened the associations between urinary total estradiol and serum total cholesterol, LDL cholesterol, and apo B. Urinary free estradiol showed a significant correlation with HDL 3 cholesterol. Urinary excretion of total testosterone was significantly negatively associated with serum cholesterol and LDL cholesterol levels only after controlling for confounding variables. There were no significant associations between hormone variables and Lp(a) values. This study suggests that variation in sex hormone production accounts for some of the variation in serum lipid levels.