Fasting C-peptide levels were markedly different between MASLD patients compared with controls (1.59 vs. 2.69 ng/mL, p = 0.002) (Fig. 2d), while GIP levels likewise did not differ between the two groups (4.34 vs. 3.37 pmol/L, p = 0.58) (Fig. 2c). This evidence concerns the gene GIP and metabolic dysfunction-associated steatotic liver disease.