Effects of long-term testosterone substitutive therapy on bone mineral content in men with hypergonadotrophic hypogonadism.

Abstract

Hypogonadism is one of the crucial risk factors for male osteopenia and osteoporosis. There are few studies on the effects of long-term and consistently administered testosterone substitutive therapy on bone mineral density in men with gonadal androgen deficiency, and their results have been susceptible to various interpretations. The aim of our study was an evaluation of bone mineral content in 26 men, aged 18-57 years, with hypergonadotrophic hypogonadism who underwent long-lasting androgen re-placement therapy with testosterone esters (Omnadren 250), which conditioned proper psychosomatic androgenization. The control group comprised 405 healthy men, aged 20-60 years, a representative sample of the local male population. Among all examined men and in the control group, trabecular, cortical and total bone mineral content at the distal radius of the nondominant hand were assessed by peripheral quantitative computed tomography using the Stratec 960 apparatus. In 11 hypogonadal men (42.3%), the trabecular bone mineral content was found to be within normal ranges; in 15 patients (57.7%) its values were below -1 standard deviation (SD) (osteopenia). In six patients (23.1%), the cortical bone mineral content was between +1 SD and the arithmetic mean, X; in 13 examined men (50%), the cortical bone mineral content was below X and above -1 SD. Osteopenia was diagnosed in six hypogonadal males, whereas osteoporosis was found in one man (cortical bone mineral content below -2.5 SD). Only in seven of the examined men (26.9%) was the total bone mineral content found within normal ranges, whereas in 19 men (73.1%) the total bone mineral content was below -1 SD (osteopenia). Despite the testosterone replacement in hypogonadal men, the greatest reduction of bone mineral content was found in its trabecular and total values. Among all the men examined, the trabecular and total bone mineral contents were below the mean of our own reference values. The results show that long-term and consecutively administered testosterone replacement in conventional doses, despite the normalization of serum androgen levels and the promotion of proper somatic development, does not simultaneously eliminate hypogonadal osteopenia in every case. The individually differentiated response to exogenous androgens is a characteristic feature of male hypogonadism. This study emphasizes the necessity of regular measurements of bone mineral density in hypogonadal men, as the densitometric parameters should be accepted as an osteologic (and very important) marker of androgenization of the male organism.