Association between low-normal thyroid function and advanced liver fibrosis in metabolic dysfunction-associated fatty liver disease patients: a retrospective cohort study

Abstract

Background: Recent studies have found that thyroid function may be associated with the occurrence and development of advanced liver fibrosis in patients with metabolic dysfunction-associated fatty liver disease (MAFLD). However, the majority of such research has consisted of cross-sectional studies. This retrospective cohort study aimed to investigate the effect of low-normal thyroid function on advanced liver fibrosis in MAFLD patients over a 5-year period.

Methods: This retrospective cohort study enrolled 825 outpatients and inpatients with MAFLD who attended the Third Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between January 2011 and December 2018. Based on plasma thyroid hormone and thyroid-stimulating hormone levels, these patients were divided into two groups, namely a low-normal thyroid function group and a strict-normal thyroid function group. The fibrosis-4 score was used to assess advanced liver fibrosis. A chi-square test was conducted to compare the occurrence of advanced fibrosis between the groups.

Results: Among the 825 MAFLD patients, 117 and 708 were defined as having low-normal thyroid function and strict-normal thyroid function, respectively. Follow-up data were available for 767 patients (93.0%) during a 5-year period. Eight (7.5%) MAFLD patients with low-normal thyroid function and 26 (3.9%) with strict-normal thyroid function developed advanced liver fibrosis and the cumulative incidence was not significantly different (P = 0.163). Stratification analysis showed that the lean MAFLD patients (body mass index ≤ 23 kg/m²) with low-normal thyroid function had a higher risk of advanced liver fibrosis than the lean MAFLD patients with strict-normal thyroid function (P < 0.05).

Conclusion: Low-normal thyroid function is associated with advanced liver fibrosis among lean MAFLD patients.

Keywords: fatty liver; hepatic fibrosis; liver metabolism; thyroid function.

Figure 1.

Kaplan–Meier curves between groups. The Kaplan–Meier curves show no significant difference in the survival of no advanced fibrosis between MAFLD patients with low-normal thyroid function and those with strict-normal thyroid function.

Figure 2.

Kaplan–Meier curves at different stratifications. Statistically significant difference is shown between patients with low-normal thyroid function and those with strict-normal thyroid function among MAFLD patients with different BMIs. No significant difference between the two groups regarding sex stratifications and age stratifications. The Kaplan–Meier curves were plotted based on the actual and the longest follow-up time of each patient.