Thyroid Function and the Risk of Non-Alcoholic Fatty Liver Disease in Morbid Obesity

Abstract

Background: An association between hypothyroidism and the risk of Non-alcoholic Fatty Liver Disease (NAFLD) has been suggested. This association remains to be elucidated in patients with morbid obesity. Aim: To evaluate the association between thyroid function and parameters of liver function and hepatic scores in patients with morbid obesity. Methods: (FLI) and BARD scores were used as predictors of hepatic steatosis and fibrosis, respectively. Results: We observed a positive association between TSH and both BARD (OR 1.14; p = 0.035) and FLI (OR 1.19; p = 0.010) in the unadjusted analysis. We found a negative association between free triiodothyronine levels and BARD (OR 0.70; p<0.01) and a positive association between free triiodothyronine levels and FLI (OR 1.48; p = 0.022). Concerning liver function, we found a positive association between total bilirubin and free thyroxine levels (β = 0.18 [0.02 to 0.35]; p = 0.033) and a negative association between total bilirubin and free triiodothyronine levels (β = -0.07 [-0.14 to -0.002]; p = 0.042). Conclusion: Higher levels of TSH and free triiodothyronine may be associated with a higher risk of NAFLD, particularly steatosis, in patients with morbid obesity.