Free Triiodothyronine Levels and Short-Term Prognosis in Chronic Heart Failure Patients With Type 2 Diabetes

Abstract

In chronic heart failure (CHF) patients with type 2 diabetes mellitus (T2DM), the role of thyroid hormone (TH) in predicting CHF severity and prognosis is unclear. The authors therefore investigated the role of TH in predicting CHF severity and prognosis in these specific patients. A total of 224 CHF patients (114 with T2DM) over a mean follow-up time of 6.56 ± 0.18 months were studied. TH, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and other parameters were measured. Free triiodothyronine (FT3) levels were lower in the T2DM group compared with the nondiabetes group (P = 0.026) and higher in the New York Heart Association (NYHA) I group than in the NYHA III and IV groups (both P < 0.05). Compared with the low NT-proBNP group, the high NT-proBNP group had lower FT3 levels (P < 0.01). NT-proBNP correlated with NYHA classes (r = 0.541, P < 0.001), and inversely correlated with left ventricular ejection fraction (r = -0.431, P < 0.001) and FT3 levels (r = -0.335, P < 0.001). In multiple linear regression analysis, NT-proBNP was significantly correlated with NYHA classes (P < 0.001), left ventricular ejection fraction (P < 0.001) and FT3 (P = 0.004). Kaplan-Meier curves showed that the low FT3 group had an increased rate of short-term adverse outcomes of CHF (log rank, χ = 9.794, P = 0.002). FT3 levels are associated with the severity of CHF and seem to reflect short-term outcomes in CHF patients with T2DM.