Low T3 syndrome and long-term mortality in chronic hemodialysis patients

AIM:To investigate the predictive value of low free T3 for long-term mortality in chronic hemodialysis(HD) patients and explore a possible causative role of chronic inflammation.METHODS:One hundred fourteen HD patients(84 males) consecutively entered the study and were assessed for thyroid function and two established markers of inflammation,high sensitivity C-reactive protein(hs CRP) and interleukin-6(IL-6).Monthly blood samples were obtained from all patients for three consecutive months during the observation period for evaluation of thyroid function and measurement of inflammatory markers.The patients were then divided in two groups based on the cut-off value of 1.8 pg/m L for mean plasma free T3,and were prospectively studied for a mean of 50.3 ± 30.8 mo regarding cumulative survival.The prognostic power of low serum f T3 levels for mortality was assessed using the Kaplan-Meier method and univariate and multivariate regression analysis.RESULTS:Kaplan-Meier survival curve showed a negative predictive power for low free T3.In Cox regression analysis low free T3 remained a significant predictor of mortality after adjustment for age,diabetes mellitus,hypertension,hs CRP,serum creatinine and albumin.Regarding the possible association with inflammation,free T3 was correlated with hs CRP,but not IL-6,and only at the first month of the study.CONCLUSION:In chronic hemodialysis patients,low plasma free T3 is a significant predictor of all-cause mortality.Further studies are required to identify the underlying mechanisms of this association.