Abstract:  Objective · To investigate the prevalence of low triiodothyronine syndrome (LT3S) in peritoneal dialysis (PD) patients and to evaluate the predictive value of long-term prognosis.  Methods · From Jan. 2009 to Dec. 2015, all patients who started PD for 3 months were enrolled. According to thyroid hormone levels, there were classified into LT3S group (218 cases) and normal T3 group (259 cases). The association between FT3 and mortality in PD patients was estimated using Cox risk regression model.  Results · Compared to the patients in normal T3 group, patients with LT3S had lower hemoglobin [(97.90±23.71)g/L vs (105.54±22.94)g/L], adjusted serum calcium [(2.06±0.35)mmol/L vs (2.17±0.27)mmol/L] (all P<0.01). Patients with LT3S had higher BNP {[311.00(134.59,776.00)pg/mL] vs [159.00(58.28,378.75)pg/mL]}, hrCRP {[2.85(0.95, 6.81)mg/L] vs [1.34(0.54, 3.32) mg/L]}
 and serum total cholesterol [(3.18±1.29)mmol/L vs (2.76±0.93)mmol/L] than that in patients with normal T3 group (all P<0.01). LVMI of LT3S group [(154.16±58.15)g/m2] vs (125.24±42.67)g/m2] was much higher than that of normal T3 group (P<0.01). Cox risk regression model indicated that FT3 was significantly associated with all-cause mortality (HR 0.51, 95% CI 0.41-0.63; P<0.01) and cardiovascular mortality (HR 0.60, 95% CI 0.45-0.81; P<0.01).  Conclusion · LT3S is common in PD patients. Lower FT3 was an independent risk factor of  all-cause and cardiovascular mortality in PD patients.

Key words:  peritoneal dialysis, low triiodothyronine syndrome, all-cause mortality, cardiovascular disease mortality