Association of Non-HDL-C with Diagnostic Parameters of Metabolic Syndrome in Patients with Hypothyroidism

Abstract

Introduction: Non-high-density lipoprotein-cholesterol (non-HDL-C) increases the risk for metabolic syndrome (MetS) in patients with hypothyroidism. Thyroid hormones i.e. T3 & T4 can increase triglyceride levels by inhibiting the activity of enzyme lipoprotein lipase. Hypothyroidism is associated with high levels of low density lipoprotein cholesterol (LDL-C) and adverse effects in number, size, and oxidation of LDL-C.

Objectives: This study is design to find the association between non-HDL-C with diagnostic parameters of MetS in patients with hypothyroidism..

Methods: In this case-control study, a total of 140 subjects (70 diagnosed hypothyroidism patients and 70 age-matched healthy controls) were enrolled, aged 30-65 years. Body mass index (BMI), waist circumference (WC), and systolic and diastolic blood pressure (SBP and DBP) were measured. Thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), fasting blood sugar (FBS), total cholesterol (TC), triglyceride (TG), and high-density lipoprotein-cholesterol (HDL-C) were estimated. Low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C), and non-HDL-C were calculated. A p<0.05 was considered statistically significant.

Results: Mean of BMI, WC, FBS, TSH, TC, TG, non-HDL-C, LDL-C, VLDL-C, SBP, and DBP were significantly elevated in cases compared to controls (p <0.001). However, mean of T3, T4, and HDL-C were significantly reduced in cases compared to controls (p<0.001). Non-HDL-C has shown a significant positive correlation with age (r = 0.315, p<0.01), TC (r = 0.451, p<0.01), TG (r = 0.227, p<0.05), LDL-C (r = 0.367, p<0.01), and VLDL-C (r = 0.230, p<0.05) among cases. However, non-HDL-C has shown a significant negative correlation with HDL-C (r = -0.280, p<0.05) among cases. Non-HDL-C significantly predicted risk for metabolic syndrome in patients with hypothyroidism (F (14, 55) = 2.716, p<0.05).

Conclusions: Non-HDL-C has shown a significant association with age and lipid abnormalities in patients with hypothyroidism. Non-HDL-C significantly predicts the risk of MetS in patients with hypothyroidism.