Thyroid function is associated with non-alcoholic fatty liver disease in chronic hepatitis B-infected subjects

Background and Aims: Associations between thyroid function and non-alcoholic fatty liver disease (NAFLD) are unknown in chronic hepatitis B (CHB)-infected patients. Thus, the aim of the study was to investigate the prevalence of thyroid dysfunction and its relationship with NAFLD in CHB. Methods: Consecutive naive CHB infected patients that had undergone liver biopsy and serum thyroid function tests between January 2007 and December 2011 were retrospective analyzed. NAFLD was diagnosed as at least 5% biopsy-proven hepatic steatosis without significant alcohol consumption. Results: A total of 1154 non-alcoholics with CHB were included, 270 (23.39%) patients were found to have NAFLD, most of them (88.5%) with mild steatosis. The prevalence of hyperthyroidism and hypothyroidism (including subclinical and overt) was 1.56% and 1.64%, respectively, both with similar rates in patients with and without NAFLD (1.85% vs 1.47%, 1.48% vs 1.69%, respectively, both P > 0.05). The serum thyroid-stimulating hormone (TSH) level in NAFLD patients was significantly higher than that in patients without NAFLD (2.22+/- 2.13 vs 1.61+/- 1.20 mIU/L, P < 0.05). After adjustment for age and gender, the elevated TSH level was associated with increased odds of having steatosis (odds ratio1.54, 95% confidence interval 1.049-2.271) instead of viral factors and hepatic inflammation and fibrosis. Conclusions: Thyroid dysfunction is not common in CHB-infected patients, and the prevalence of hypothyroidism in CHB individuals with or without NAFLD is similar. However, increased serum TSH concentration at the normal range is a significant predictor of hepatic steatosis in patients with CHB.