Association of thyroid hormones with metabolic syndrome and its components in postmenopausal Chinese women

Abstract

To evaluate the association between thyroid hormones (TH) and metabolic syndrome (MS) in postmenopausal women (PmW), a cross-sectional study was conducted with a sample of 1000 participants of PmW (40–65 years). Thyroid stimulating hormone (TSH) and free thyroxine (fT4) were evaluated. The MS was defined using the International Diabetes Federation (IDF) ethnicity-specific definitions for Asian. Participants were classified into three groups according to the TSH reference range: high-TSH (≥4.2 mU/L), low-TSH (<0.1mU/L), and normal-TSH (0.1–4.2 mU/L) group. Serum triglycerides (TG) levels were higher in low-TSH group and high-TSH group compared with normal-TSH group (p < .05). The whole sample was stratified into <60 and ≥60 years subgroups. In the ≥60 years group, fT4 was negatively correlated with waist circumference (WC) (p = .028) and positively correlated with fasting blood glucose (FBG) (p = .043), meanwhile TSH was positively correlated with WC only in the control subjects (p = .014). No difference was found between TH and the number of MS components. It was demonstrated that serum fT4 levels were associated with FBG and WC, while TSH was associated with WC in elderly PmW without MS.