Low Free Triiodothyronine as a More Sensitive Predictor of Survival Than Total Testosterone among Dialysis Men

Background: Some endocrine disorders, previously considered benign, may be related to a poorer prognosis for patients with renal failure. Both low serum free triiodothyronine (fT3) and low total testosterone (TT) concentrations have been considered as predictors of death in dialysis patients, but the results of studies are inconsistent. In our study, we evaluated the relationships of the serum thyroid hormone levels and the total testosterone levels with survival in male dialysis patients. Methods: Forty-eight male dialysis patients, 31 on hemodialysis (HD) and 17 on peritoneal dialysis (PD), aged 61.4 ± 10.0, 59.2 ± 12.2 years, respectively, were included in the study. Serum thyroid hormones and total testosterone were measured. Results: During the 12-month follow-up, nine all-cause deaths were recorded. The concentrations of fT3 were significantly lower in those who died than in the survivors (p = 0.001). We did not observe any statistically considerable differences between the group of men who died and the rest of the participants in terms of the total serum testosterone concentration (p = 0.350). Total testosterone positively correlated with fT3 (r = 0.463, p = 0.009) in the HD group. Conclusions: In the group of male dialysis patients, the serum concentration of fT3 had a better prognostic value in terms of survival than the total testosterone. A linear relationship between the fT3 levels and testosterone levels in men undergoing hemodialysis may confirm the hypothesis that some of the hormonal changes observed in chronic kidney disease (CKD) may have a common cause.