Association of low muscle strength with metabolic dysfunction-associated fatty liver disease: A nationwide study

BACKGROUND There is limited evidence regarding the association between muscle strength and metabolic dysfunction-associated fatty liver disease (MAFLD). AIM To investigate the association between muscle strength and MAFLD in the general population in Korea. METHODS This nationwide representative cross-sectional study included 31649 individuals aged ≥ 19 years who participated in the Korea National Health and Nutrition Examination Survey between 2015 and 2018. Odds ratios (ORs) and 95% confidence intervals (95%CIs) for MAFLD according to sex-specific quartiles of muscle strength, defined by relative handgrip strength, were calculated using multivariable logistic regression analysis. Additionally, multivariable logistic regression analysis was used to assess the association between muscle strength and probable liver fibrosis in patients with MAFLD. RESULTS Of all the participants, 29.3% had MAFLD. The prevalence of MAFLD was significantly higher in the lower muscle strength quartile groups for all participants, sexes, and age groups (P < 0.001). A 1.92-fold (OR = 1.92, 95%CI: 1.70–2.16) and 3.12-fold (OR = 3.12, 95%CI: 2.64–3.69) higher risk of MAFLD was observed in the lowest quartile (Q1) group than in the other groups (Q2–Q4) and the highest quartile (Q4) group, respectively. The ORs of MAFLD were significantly increased in the lower muscle strength quartile groups in a dose-dependent manner (P for trend < 0.001). These associations persisted in both sexes. An inverse association between muscle strength and the risk of MAFLD was observed in all subgroups according to age, obesity, and diabetes mellitus. In patients with MAFLD, the odds of severe liver fibrosis were higher in Q1 (OR = 1.83, 95%CI: 1.25–2.69) than in other groups (Q2–Q4). CONCLUSION Among Korean adults, low muscle strength was associated with an increased risk of MAFLD and liver fibrosis in patients with MAFLD.