Nutritional State Alters the Association between Free Triiodothyronine Levels and Mortality in Hemodialysis Patients

WOS: 000290313300003PubMed ID: 21389695Background: Serum free triiodothyronine (fT3) level is suggested to be a risk factor for mortality in unselected dialysis patients. We investigated the prognostic value of serum fT3 levels and also low-T3 syndrome on overall survival in a large cohort of hemodialysis (HD) patients with normal thyroid-stimulating hormone levels. Methods: A total of 669 prevalent HD patients were enrolled in the study. Serum fT3 level was measured by enzyme immune assay in frozen sera samples at the time of enrollment. Overall mortality was assessed during 48 months of follow-up. Results: Baseline fT3 was 1.47 +/- 0.43 (0.01-2.98) pg/ml, and low-T3 syndrome was present in 71.7% of the cases. During a mean follow-up of 34 +/- 16 months, 165 (24.7%) patients died. fT3 level was a strong predictor for mortality in crude and adjusted Cox models including albumin or high-sensitivity C-reactive protein (hs-CRP). Further adjustment for both albumin and hs-CRP made the impact of fT3 on mortality disappear. The presence of low-T3 syndrome was associated with mortality in only the unadjusted model. Conclusions: Low-T3 syndrome is a frequent finding among HD patients, but it does not predict outcome. However, serum fT3 level is a strong and inverse mortality predictor, in part explained by its underlying association with nutritional state and inflammation. Copyright (C) 2011 S. Karger AG, BaselLoo and Hans Osterman's Foundation; Swedish Kidney Association; Karolinska Institutet's Centre for Gender Medicine; Fresenius Medical Care, Istanbul, TurkeyWe thank all staff of the participating HD centers and patients for their help and support. J.J.C. obtained support from the Loo and Hans Osterman's Foundation, the Swedish Kidney Association and the Karolinska Institutet's Centre for Gender Medicine.; This study was supported by Fresenius Medical Care, Istanbul, Turkey, with an unrestricted grant. E.O. is member of the scientific advisory board of Fresenius Medical Care, Turkey, and A.B. is the Medical Director of Fresenius Medical Care, Turkey