Metabolic Effect on Serum Mac-2 Binding Protein Glycan Isomer Level and Its Normal Range in the Health Checkup...

Liver fibrosis is central to chronic liver disease prognosis, including metabolic dysfunction-associated steatotic liver disease (MASLD). Mac-2 binding protein glycan isomer (M2BPGi) is a recognized liver fibrosis marker, but lacks an established reference range in healthy populations, thereby limiting clinical use.

This cross-sectional study analyzed 3623 Japanese adults undergoing routine health checks (2020-2021), excluding those with hepatitis B or C. Participants had physical and laboratory assessments, including serum M2BPGi, metabolic parameters, and liver indices. The fatty liver index (FLI) and Fibrosis-4 (FIB-4) index assessed hepatic steatosis and fibrosis. Multiple regression identified independent determinants of M2BPGi, and a normal reference range was established from participants with all metabolic and liver factors within normal limits.

Participants' mean age was 42.3 years (90.5% male). Median M2BPGi was 0.44 COI (IQR: 0.32-0.60). Higher M2BPGi correlated with increased BMI, waist circumference, glucose, lipid levels, liver enzymes, FLI and FIB-4. Regression analysis identified age, sex, BMI, waist, AST, GGT, HDL-C, fasting glucose, and FIB-4 as independent predictors of M2BPGi; alcohol intake was not significant. Females displayed significantly higher M2BPGi than males. Among 1350 participants with completely normal parameters, the reference M2BPGi was 0.41-0.43 COI in male and 0.46-0.54 COI in female.

M2BPGi levels are independently influenced by metabolic factors and sex, and the study establishes sex-specific normal reference ranges in healthy Japanese adults. M2BPGi above these limits should prompt further metabolic and hepatic evaluation.