Usefulness of health checkup-based indices in identifying metabolic dysfunction-associated steatotic liver disease

The application of indices in the context of metabolic dysfunction-associated steatotic liver disease (MASLD) remains unexplored. We aimed to validate the ability of alanine aminotransferase (ALT), fatty liver index (FLI), and hepatic steatosis index (HSI) to identify MASLD during health checkups.

We recruited 627 participants and utilized their health checkup data and ultrasound to assess the potential of using ALT, FLI, and HSI as indices for MASLD; this was indicated by the area under the curve (AUC) and restricted cubic spline (RCS) model. The optimal, rule-out (sensitivity ≥90%), and rule-in (specificity ≥90%) cutoff values of each index for identifying MASLD were reported.

Among participants with a median age of 46 years, the prevalence of MASLD was 28% in total (38% in males and 18% in females). RCS models confirmed a linear association between indices and MASLD. ROC analyses indicated that the AUC of ALT in identifying MASLD was 0.79 for the total cohort, 0.81 for males, and 0.69 for females. The optimal, rule-out, and rule-in cutoff values for ALT were 21, 13, and 29, respectively. Similarly, the AUC of FLI/HSI in identifying MASLD was 0.90/0.88 for the total cohort, 0.86/0.85 for males, and 0.93/0.90 for females. Considering the reference cutoff values, distinct cutoff values were observed between the sexes for FLI, while HSI had similar cutoff values.

This study demonstrated that ALT > 30 IU/L is a reasonable cutoff value to rule-in MASLD. ALT, FLI, and HSI are reliable indices for identifying MASLD during health checkups.