Thyroid function and the risk of non-alcoholic fatty liver disease: The Rotterdam Study

2016 The Journal of Clinical Endocrinology and Metaboli In press;(jc20161300)

CONTEXT: Although thyroid function is associated with several risk factors of non-alcoholic fatty liver disease (NAFLD), its role in NAFLD development remains unclear. OBJECTIVE: We aimed to prospectively investigate the association between variations in thyroid function and NAFLD. DESIGN AND SETTING: The Rotterdam Study, a large population-based, prospective cohort study. PARTICIPANTS AND MAIN OUTCOME MEASURES: Participants with thyroid function measurements at baseline and NAFLD data (i.e. at baseline fatty liver index/ at follow-up ultrasound) were eligible. Transient elastography was performed to assess the presence of fibrosis in patients with NAFLD, using the liver stiffness measurements >/=8 kilopascals as cut-off for clinically relevant fibrosis. The association between thyroid parameters and incident NAFLD was explored by using logistic regression models. RESULTS: A total of 9419 participants (mean age 64.75 years) were included. The median follow-up time was 10.04 years (interquartile range: 5.70-10.88 years). After adjusting for age, sex, cohort, follow-up time, use of hypolipidemic drugs and cardiovascular risk factors, higher free thyroxine levels were associated with a decreased risk of NAFLD (Odds ratio [OR], 0.42; 95% confidence interval [CI], 0.28-0.63). In line, higher thyroid-stimulating hormone levels were associated with an increased risk of having clinically relevant fibrosis in NAFLD (OR, 1.49; CI, 1.04-2.15). Compared to euthyroidism, hypothyroidism was associated with a 1.24-fold higher NAFLD risk (CI, 1.01-1.53). Moreover, NAFLD risk decreased gradually from hypothyroidism to hyperthyroidism (p-trend 0.003). CONCLUSION: Lower thyroid function is associated with an increased NAFLD risk. These findings may lead to new avenues regarding NAFLD prevention and treatment.

Pubmed : 27270473