Abstract: 【Abstract】Objective To examine the correlation of low triiodothyronine (T3) syndrome with residual renal function and survival in patients undergoing maintenance peritoneal dialysis (PD). Methods Baseline data including thyroid hormone tests were recruited from PD patients treated in our Hospital in April 2009, and a seven- year follow- up was conducted. The relationship between serum free T3 (FT3) and renal Kt/V (rKt/V) was explored using one-way ANOVA and linear regression analysis, and Cox proportional hazards modeling was used to explore the association between serum FT3 and all-cause mortality. Results A total of
125 subjects were included in this study, of whom 34 patients (27.2%) presented with low T3 syndrome. In the patients with the highest rKt/V, serum FT3 was higher (F=12.779, P<0.001) and the prevalence of low T3 syndrome was the lowest (14.3%, χ²=10.175, P=0.038) as compared with the other two groups. Univariate regression analysis revealed that the level of serum FT3 was positively correlated with rKt/V (r=0.270, P=0.002), protein equivalent of nitrogen appearance (PNA) (r=0.217, P= 0.016), hemoglobin (HGB) (r=0.183, P=0.044) and serum albumin (ALB) (r=0.424, P<0.001), and was negatively correlated with serum C-reactive protein (CRP) (r=-0.311, P<0.001) and age (r=-0.346, P<0.001). Multivariate regression analysis showed that rKt/V remained the independent influencing factor on serum FT3 level after adjusting sex, age, serum ALB, CRP, HGB and PNA (β=0.284, P=0.004). Cox regression analysis showed that serum FT3 remained to be an independent predict factor for all-cause mortality in PD patients after adjusting sex, age, HGB, PNA, serum ALB, CRP and rKt/V (HR 0.303, 95% CI 0.103～0.889, P=0.030). Conclusions Our study demonstrates that the presence of serum FT3 syndrome is closely associated with residual renal function and that serum FT3 can independently predict death risk in PD patients.

Key words: Peritoneal dialysis, Residual renal function, Low T3 syndrome