Endogenous sex steroid, GH and IGF-I levels in normal elderly men: Relationships with bone mineral density and markers of bone turnover

There are studies concerning the association among endogenous sex steroids, growth hormone (GH), insulin-like growth factor-I (IGF-I) and bone mineral density (BMD) in both men and women. However, little is known concerning t he association of these parameters with markers of bone turnover in healthy elderly men. We studied the association of BMD (dual energy X-ray absorpti ometry of spine, hip and forearm) and markers of bone turnover (bone-specif ic alkaline phosphatase, serum C-terminal propeptide of type I collagen, an d serum osteocalcin reflecting formation, urine deoxypyridinoline and calci um excretion in relation to creatinine excretion reflecting resorption) wit h endogenous sex steroids, GH and IGF-I in 14 elderly normal men (age range 60-79 years). There was a negative correlation between age and dehydroepia ndrosterone sulphate (DHEAS) (r = -0.60, p = 0.022) and a positive correlat ion between GH and IGF-I (r = 0.53, p = 0.048). Serum estradiol concentrati ons correlated with BMD at distal 1/3 radius (r = 0.41, p = 0.1) and mid-ra dius (r = 0.47, p = 0.08), and negatively correlated with age (r = -0.45, p = 0.09). There was no correlation of estradiol with bone turnover markers, testosterone, free testosterone, DHEAS, GH and IGF-I. Serum GH and IGF-I l evels showed no correlation with BMD (all sites) and bone turnover markers. Serum total testosterone concentrations positively correlated with BMD at distal 1/3 radius (r = 0.47, p = 0.09), femoral neck (r = 0.56, p = 0.037) and Ward's triangle (r = 0.49, p = 0.07). These data suggest that serum est radiol and testosterone levels are associated with BMD in elderly men, poss ibly indicating their contribution to skeletal maintenance in old age. Howe ver, correlations of IGF-I, GH and DHEAS with BMD and bone turnover markers are lacking in the group studied. (J. Endocrinol. Invest. 24: 408-414, 200 1) (C) 2001, Editrice Kurtis.