Abstract
Background and Objectives: The pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) remains incompletely understood. However, recent studies highlight the interactions between muscle, liver, and adipose tissue. This study aimed to explore the relationships between clinical indicators of MASLD and sarcopenia, cardiorespiratory fitness, fatigue, and mood. Materials and Methods: The study involved 60 participants, including 28 healthy controls and 32 with MASLD, categorized into two disease subgroups: 15 with MASL and 17 with metabolic dysfunction-associated steatohepatitis (MASH). Participants completed an incremental speed shuttle walk test to evaluate cardiorespiratory fitness, a hand-held dynamometer assessment for appendicular muscle strength, and the timed up and go test for physical performance. Physical activity level, fatigue, quality of life, and emotional state were assessed using questionnaires. The test results were compared between groups and with disease characteristics. Results: MASL and MASH groups showed reduced cardiorespiratory fitness (p < 0.001). The knee extensors were significantly weaker in both MASL and MASH groups (p < 0.001 and p = 0.001, respectively). The MASH group reported higher levels of depression and negative health perception (p = 0.006 and p = 0.03, respectively). Muscle strength in patients with MASLD showed a significant negative association with depression (OR = -0.384, 95% CI: -3.10 to -0.74, p = 0.003), intrahepatic triglyceride content (OR = -0.287, 95% CI: -1.31 to -0.11, p = 0.023), and LDL (OR = -0.286, 95% CI: -0.02 to -0.33, p = 0.03). In contrast, a positive association was observed between VO(2) and muscle strength (OR = 0.531, 95% CI 1.27 to 3.47, p < 0.001). Conclusions: This study suggests that muscle strength is linked to key metabolic parameters, such as hepatic fat, LDL levels, and aerobic capacity, that may contribute to the development and progression of MASLD. Interventions aimed at preserving or enhancing muscle strength in MASLD patients may be essential for preventing liver damage and improving metabolic health.