Prevalence of metabolic syndrome in hypothyroid patients under levothyroxine therapy

Abstract

Aim: Since thyroid hormones have an impact on lipid and glucose metabolism, thyroid dysfunction is a risk factor for cardiovascular diseases. Metabolic syndrome (MS) is related to higher risk of cardiovascular disease, diabetes mellitus, and all-cause mortality. Studies have demonstrated that thyroid dysfunction corresponds to a higher prevalence of MS. Additionally, some studies have showed patients with MS had a higher prevalence of hypothyroidism. We aimed to investigate whether hypothyroid patients being treated with levothyroxine still have a higher prevalence of metabolic syndrome or not. Methods: One hundred and eighty-six hypothyroid patients (175 female, 11 male) using levothyroxine treatment were included in the study. Demographic, anthropometric and laboratory measures were recorded. International Diabetes Federation (IDF) criteria were used for diagnosis of MS. Results: The prevalence of MS was 52% in hypothyroid patients using levothyroxine. Mean age was 48.44±14.90 years. Mean TSH was 1.94±1.11 uIU/L and mean free T4 was 1.06±0.20 (ng/ dL). Mean weekly levothyroxine dose was 537.01 mcg. Weekly levothyroxine dose was positively correlated with weight (r2:0.188, p:0.010), BMI (r2:0.227, p:0.026) and waist circumference (r2:0.164, p:0.026). Weekly levothyroxine dose was also positively correlated with LDL-cholesterol (r2:0.167, p:0.031) and HbA1c (r2:0.180, p:0.034) levels. Weekly levothyroxine dose was not correlated with other cardiometabolic risk factors (p>0.05). Conclusions: The prevalence of metabolic syndrome is still high in hypothyroid patients under levothyroxine treatment. Moreover, more comprehensive studies should be performed in a larger-scale population to enlighten this association. © 2018, Logos Medical Publishing. All rights reserved.