Sex Steroid Levels and Cortical Bone Size in Young Men Are Associated with a Uridine Diphosphate Glucuronosyltransferase 2B7 Polymorphism (H268Y)

Context: Sex steroids are involved in the regulation of pubertal cortical bone expansion in males. In vitro studies have indicated that the enzyme uridine diphosphate glucuronosyltransferase (UGT) 2B7 has the capacity to glucuronidate sex steroids and their metabolites. Objective: Our objective was to determine the impact of the H268Y polymorphism in the UGT2B7 gene on interindividual variation of serum levels of sex steroids and cortical bone dimensions. Participants: The population-based cohort Gothenburg Osteoporosis and Obesity Determinants study consists of 1068 young adult Swedish men (age 18.9 yr). Main Outcome Measures: Serum levels of sex steroids and the three major glucuronidated androgen metabolites, androstane-3α,17β-diol-17glucuronide, androstane-3α,17β-diol-3glucuronide, and androsterone-glucuronide, were analyzed. Cortical and trabecular volumetric bone mineral density and cortical bone size were measured by peripheral quantitative computer tomography. Results: Serum levels of testosterone...