Testosterone in renal transplant patients: effect on body composition and clinical parameters

Background: Clinical studies have demonstrated that, after renal transplantation (TX), testosterone deficiency (TD) at the time of the procedure is independently associated with lower survival of the patient and graft. However, data between TD and the functional CAG polymorphism of the androgen receptor promoter (AR) are discordant. We investigated the prevalence of TD and its association with body composition, biochemical parameters, the Aging Males’ Symptoms rating scale (AMS) domains and AR polymorphism. Methods: In 112 TX patients, we assessed the AMS, biochemical/hormonal (FSH/LH/TT) anthropometric/bioimpedance analysis parameters, and AR CAG polymorphism of AR by gene sequencing. Results: Median values of total testosterone (TT) were 340 ng/dl and 52% of TX patients were affected by TD. Significant correlations between TT and FSH and FSH and LH (p = 0.005, p < 0.0001, respectively) were found. TD patients had lower estimated glomerular filtration rate (eGFR) and hemoglobin (Hb) (p = 0.034, p = 0.022 respectively) and showed higher values of C-reactive protein (p = 0.023) and fat tissue index/adipose tissue mass (p = 0.034 and p = 0.021, respectively), and lower values of serum albumin (p = 0.003) and high-density lipoprotein-cholesterol (p = 0.038) levels. Significant differences were found in the number of patients on mammalian target of rapamycin inhibitors immunosuppressant therapy (p = 0.045). Logistic regression analysis did not show any correlation between age, AMS scores, TT or CAG repeat length, gonadotropins, time of the transplant, and dialysis. Conclusions: Our results suggest that in TX recipients an appropriate sexual hormonal evaluation should be performed, as we found a high prevalence of TD. However, further studies are needed to clarify the association between TD and patient and graft survival.