ABSTRACT
BACKGROUND: Thyroid hormones are one of the key factors involved in energy, lipid, and glucose metabolisms. Many studies have been conducted to establish the association between thyroid function and metabolic syndrome. This study aimed to identify the association between thyroid hormone and metabolic syndrome in euthyroid Korean male adults.METHODS: Using data from the sixth Korea National Health and Nutrition Examination Survey from 2013 to 2015, this cross-sectional study of 2,285 male adults was conducted. Subjects who had thyroid diseases and were not euthyroid were excluded. The included subjects were divided into four groups according to free thyroxine (fT4) and thyroid-stimulating hormone levels. We analyzed the prevalence and adjusted odds ratio of metabolic syndrome according to thyroid hormone levels.RESULTS: The prevalence of metabolic syndrome and its components decreased constantly from the lowest fT4 quartile to the highest fT4 quartile. Compared with that in the lowest fT4 quartile, the adjusted odds ratio of hypertriglyceridemia in the highest fT4 quartile was 0.651.CONCLUSION: In euthyroid subjects, fT4 levels are associated with metabolic syndrome and all its components.