Gonadal function and immunosuppressive therapy after renal transplantation

End-stage renal disease is associated with disorders in hypothalamic-pituitary-gonadal function. Immunosuppressive therapies may influence the restoration of normal levels of gonadal hormones after renal transplantation. The aim of the present study was to evaluate the hormonal status of successful renal transplant recipients who were treated with different immunosuppressive agents. Methods. Testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured in 59 male renal transplant recipients with stable graft function with serum creatinine < 2.5 mg/dL. Patients were treated with three different immunosuppressive regimens: group I, calcineurin inhibitors (CI; n = 15), group II, sirolimus without calcineurin inhibitors (SRL; n = 15), group III, sirolimus in combination with calcineurin inhibitors (SRL + CI; n = 29). Results. Testosterone was significantly lower in group II versus group I (3.12 +/- 1.23 versus 4.39 +/- 1.53 ng/mL; P < .0197). Group III had higher testosterone values than group II, but lower than group I. FSH and LH were also higher in the SRL group, but the differences were not statistically significant, perhaps because of the small number of patients. No relationship was found between testosterone blood levels and age, posttransplant follow-up, renal function, time on dialysis, body mass index, steroid use, or posttransplant diabetes. Conclusion. Sirolimus seems to impair the improvement of gonadal function after renal transplantation. Further prospective studies are needed to confirm these data before patients are advised of this potential side effect.