Subgroup analysis based on disease severity from 3 Asian studies revealed that the average irisin levels were higher in the NAFLD group than in the healthy group (WMD = 25.1 (22.85, 27.51) ng/ml, P < 0.05 and WMD = 13.52 (22.85, 27.51) ng/ml, P < 0.05, respectively). Here, FNDC5 is linked to metabolic dysfunction-associated steatotic liver disease.