[Effect of immunosuppression-induced hypogonadism on bone metabolism after heart transplantation].

BACKGROUND AND

OBJECTIVE

Accelerated bone loss is a well recognized complication after cardiac transplantation (HTx). The role of an immunosuppressive-induced hypogonadism, a well-known cause of osteoporosis in men and its prevention are less defined after HTx. The aim of this study was first, to evaluate the incidence of hypogonadism after HTx and its influence on bone mineral metabolism and second, to assess the effect of a testosterone replacement therapy in hypogonadal transplants.

PATIENTS AND

METHODS

Due to hormonal status, 88 male cardiac transplants were randomised to a normogonadal or hypogonadal group. At baseline as well as after 1 and 2 years bone mineral density (BMD g/cm (2), T-score) was measured at the lumbar spine with DEXA. All patients received a basic therapy of calcium and vitamin D. The hypogonadal patients received additional testosterone.

RESULTS

21 patients (24 %) showed an age-independent hypogonadism. Hypogonadal transplants showed a significant lower BMD (p < 0.001) (BMD = 0.8070 g/cm (2), T-value = -2.6514) than normogonadal patients (BMD = 0.9882 g/cm (2), T-value = -1.0568). Despite testosterone replacement hypogonadal patients showed no significant additional increase in BMD over 1 - 2 years compared with the normogonadal.

CONCLUSION

Male cardiac transplants in all age groups show an high prevalence of hypogonadism (approximately 25 %) which contributes to a significant bone loss. An additional testosterone substitution did not significantly increase BMD.