Association between metabolic dysfunction‐associated steatotic liver disease and myosteatosis measured by computed tomography

Abstract

AbstractBackgroundIn 2023, the concept of metabolic dysfunction‐associated steatotic liver disease (MASLD) was introduced as an alternative to non‐alcoholic fatty liver disease (NAFLD). We aimed to assess the quantity and quality of skeletal muscle using each of these diagnostic classifications.MethodsThis cross‐sectional study included 18 154 participants (11 551 [63.6%] men and 6603 [36.4%] women, mean age 53.0 ± 8.8). The participants were classified into four categories: neither steatotic liver disease (SLD), NAFLD only, MASLD only or both SLDs. An appendicular skeletal muscle mass adjusted for body mass index of <0.789 for men and <0.512 for women was defined as sarcopenia. The total abdominal muscle area (TAMA) at the L3 vertebral level was segmented into normal‐attenuation muscle area (NAMA), low‐attenuation muscle area and intermuscular/intramuscular adipose tissue. Myosteatosis was defined by a T‐score < −1.0 of the NAMA/TAMA index, which was calculated by dividing the NAMA by the TAMA and multiplying by 100.ResultsUsing subjects with neither SLD as a reference, the multivariable‐adjusted odds ratios (ORs) for sarcopenia were significantly increased in those with MASLD, with adjusted ORs (95% confidence interval [CI]) of 2.62 (1.94–3.54) in the MASLD‐only group and 2.33 (1.92–2.82) in the both SLDs group, while the association was insignificant in those with NAFLD only (adjusted OR [95% CI]: 2.16 [0.67–6.94]). The OR for myosteatosis was also elevated in the MASLD groups, with an OR (95% CI) of 1.75 (1.52–2.02) in subjects with MASLD only and 1.70 (1.57–1.84) in those with both SLDs, while it was slightly decreased in subjects with NAFLD only (0.52 [0.29–0.95]).ConclusionsEmploying the MASLD concept rather than that of the NAFLD proved to be more effective in distinguishing individuals with reduced muscle mass and compromised muscle quality.