Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

Sarcopenia and metabolic dysfunction-associated steatotic liver disease: The role of exercise-related biomarkers

The etiology, risk factors, and management of sarcopenia and metabolic dysfunction-associated steatotic liver disease (MASLD) are comparable, which prompted the investigators to search for a particular diagnostic or prognostic biomarker that was involved in both disorders. Peptides or proteins known as myokines, or exerkines, are produced and secreted by contracted muscles. Myokines work similarly to hormones in their actions. One common clinical hallmark of sarcopenia and MASLD is physical inactivity, which is associated with alterations in the levels of myokines. Irisin is a positive regulator of muscle size that is elevated in the biological fluids during exercise. Significantly low levels were observed in the pathological conditions associated with physical inactivity. The serum levels of irisin are significantly higher in MASLD patients, while their levels were lower in risk factors of MASLD, e.g., diabetes mellitus, obesity, and insulin resistance. In sarcopenia with obesity (sarcopenic obesity) or with a normal build, serum irisin levels are significantly lower than in healthy subjects. Therefore, serial determination of irisin levels that showed a transition from higher to lower levels in MASLD indicated the development of sarcopenia in those patients.

Correlation of sarcopenia with progression of liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease: a study from two cohorts in China and the United States

OBJECTIVE

The objective of this study was to investigate the association between sarcopenia and liver fibrosis in patients aged 18-59 years with metabolic dysfunction-associated steatotic liver disease (MASLD) and to assess the potential of sarcopenia as a risk factor for the progression of liver fibrosis.

METHODS

The study included 821 patients with MASLD in the US cohort and 3,405 patients with MASLD in the Chinese cohort. Liver controlled attenuation parameters (CAP) and liver stiffness measurements (LSM) were assessed by vibration-controlled transient elastography (VCTE) to evaluate the extent of hepatic steatosis and fibrosis. Sarcopenia was assessed by measuring appendicular skeletal muscle mass (ASM) and calculating ASMI. To analyze the relationship between sarcopenia, ASMI, and liver fibrosis, logistic regression models, multivariate-adjusted models, and restricted cubic spline (RCS) models were employed, with stratification and interaction analyses.

RESULTS

The results demonstrated that patients with sarcopenia exhibited a markedly elevated risk of significant liver fibrosis, advanced liver fibrosis, and cirrhosis compared to those without sarcopenia in both cohorts. After adjusting for confounding variables, sarcopenia was identified as an independent risk factor for the progression of liver fibrosis in patients with MASLD. A significant negative correlation was observed between ASMI and the severity of liver fibrosis, with a progressive reduction in the risk of liver fibrosis associated with increasing ASMI. Additionally, a non-linear feature was evident in some liver fibrosis indicators. Subgroup analysis further corroborated the finding that the harmful effect of sarcopenia on liver fibrosis was consistent across all identified subgroups.

CONCLUSION

Sarcopenia may be associated with the progression of liver fibrosis in patients with MASLD. Monitoring ASMI may assist in identifying individuals at an elevated risk of liver fibrosis in MASLD patients.