New nomenclature and subclassification of steatotic liver disease and loss of skeletal muscle mass: A longitudinal cohort study.

Aims: Identifying risk factors for sarcopenia is important due to its significant effect on health. The association between sarcopenia and the newly proposed steatotic liver disease (SLD) and its subclassification has largely been unexplored.

Methods: This longitudinal cohort study included 67 905 adults who underwent at least two health checkup examinations. SLD participants were categorized as cryptogenic SLD, metabolic dysfunction-associated SLD, metabolic dysfunction-associated alcoholic liver disease, or alcoholic liver disease. Appendicular skeletal muscle mass (ASM) was evaluated by bioelectrical impedance analysis.

Results: The average duration of follow-up was 5.9 years. The annual ASM change was -31.0 g (95% CI -32.3, -29.6) and -38.3 g (-40.3, -36.3) in participants without and with SLD, respectively. When assessed based on SLD severity, annual ASM loss was fastest in SLD participants with Fibrosis-4 score ≥1.3, followed by those with Fibrosis-4 score <1.3 and those without SLD. In multivariable adjusted analysis, annual ASM loss was fastest in participants with metabolic dysfunction-associated alcoholic liver disease (-49.8 g; -93.1, -6.5), followed by those with metabolic dysfunction-associated SLD (-24.7 g; -60.4, 11.1), and alcoholic liver disease (-24.4 g; -91.1, 42.3), and slowest in those with cryptogenic SLD (reference). This pattern was more pronounced in participants with Fibrosis-4 score ≥1.3.

Conclusion: The loss of skeletal muscle mass was fastest in the participants with metabolic dysfunction-associated alcoholic liver disease, followed by participants with metabolic dysfunction-associated SLD, alcoholic liver disease, and cryptogenic SLD. Particular attention to prevent sarcopenia should be given to SLD patients with cardiometabolic risk factors or alcohol consumption, especially in patients with advanced fibrosis.