The cardiovascular disease risks of nonthyroidal illness syndrome and inflammatory responses on patients with chronic kidney disease: From the association to clinical prognosis

Abstract

Summary: Background: Previous data have suggested the potential risk of low serum-free triiodothyronine (FT3) on the cardiovascular disease (CVD) events in patients with end-stage renal disease (ESRD). However, the roles of FT3 and interleukin-6 (IL-6) in the developing of CVD events in patients with chronic kidney disease (CKD) have not been investigated. Patients and Methods: A total of 176 consecutive patients with CKD underwent thyroid function, IL-6, and echocardiography evaluation. They were divided into two subgroups: group I, 77 patients with IL-6 >200 ng/L, and group II, 99 patients with IL-6 <200 ng/L. The total patients were also divided into two subgroups according to their serum FT3: group A, 83 patients with FT3 <4.0 pmol/L, and group B, 93 patients with FT3 >4.0 pmol/L. Results: Serum FT3 (β = -0.21, P < 0.01), IL-6 (β = 0.48, P < 0.01), and glutathione peroxidase (GSH-Px, β = -0.58, P < 0.01) were found independently associated with left ventricular mass index (LVMI). Patients with higher IL-6 had significantly higher CVD incidence than those with IL-6 <200 ng/L (HR 1.98, P = 0.014); Patients with lower FT3 had significantly higher CVD incidence than those with FT3 >4.0 pmol/L (HR 1.81, P = 0.038), when extensive demographics, comorbidities and laboratory adjustments were made. Conclusions: Serum levels of FT3 and IL-6 were associated with the LVMI and previous CVD events; lower FT3 and higher IL-6 were strong predictors of subsequent CVD events in patients with CKD.