Thyroid dysfunction in obese adults in relation to nonalcoholic fatty liver disease

Abstract

Background Hormones of the thyroid gland play an important role in the regulation of various metabolic processes. Disturbances in thyroid hormone concentrations may lead to hyperlipidemia and obesity, thus contributing to nonalcoholic fatty liver disease (NAFLD). Aim To evaluate thyroid dysfunction and determine its possible relationship to NAFLD in obese adults. Patients and methods Our cross-sectional study recruited 100 obese patients, who were subjected to full medical history, physical examination, abdominal ultrasonography, and routine laboratory tests in addition to liver function and thyroid function tests. NAFLD was recognized on the basis of ultrasonographic findings, and in the absence of other causes of liver disease. Results The patients were divided into two groups: group 1 (65 patients) with NAFLD and group 2 (35 patients) without NAFLD. Out of 100 patients recruited into the study, the most common thyroid dysfunction was overt hypothyroidism (22%), followed by (9%) subclinical hypothyroidism. Twenty-six (40%) patients with NAFLD were found to have thyroid dysfunction, of them eight (12.3%) NAFLD patients had subclinical hypothyroidism, and 18 (27.7%) NAFLD patients had overt hypothyroidism. Although prevalence of thyroid dysfunction (whether overt hypothyroidism or subclinical hypothyroidism) was 22 and 9%, respectively, among patients with obesity, there was nonsignificant positive correlation between BMI and thyroid-stimulating hormone (r=0.051 and P=0.612). Multivariate regression analysis showed that fatty liver, obesity index, and dyslipedemia were predictors of thyroid dysfunction in obese patients. Conclusion Thyroid hypofunction is common in obese patients with NAFLD, which has implications for screening for hypothyroidism in patients with NAFLD and for the administration of appropriate therapy for hypothyroidism.

Keywords

• hypothyroidism
• nonalcoholic fatty liver disease
• obesity