Relationship of leptin and sex hormones to bone mineral density in men.

Sex hormones are strongly associated with bone mineral density (BMD) in adult humans. Leptin, a hormonal product of the OB gene, also appears to be associated with BMD, but results from previous studies are conflicting. Most of the studies in this area have been in women and apparently none have simultaneously analyzed the relationship of estradiol, testosterone, and leptin with BMD in healthy men. To address these issues, serum sex hormones, sex-hormone-binding globulin (SHBG), leptin, dehydroepiandrosterone sulfate (DHEAS), and insulin were measured in 50 apparently healthy men, 18-66 years of age. After controlling for age and body mass index (BMI), BMD correlated positively with estradiol ( p=0.007) and testosterone ( p=0.019), but negatively with leptin ( p=0.001). No significant correlations between BMD and SHBG, DHEAS, or insulin were observed. In multiple regression analysis with age, BMI, estradiol, testosterone, and leptin as the independent variables, only age ( p<0.05), BMI ( p<0.001), and leptin ( p=0.004) were significantly related to BMD. These findings suggest that in men, leptin may have an important negative relationship with BMD.