Miya A, Nakamura A, Miyoshi H, et al. - Researchers intended to determine if there is a connection between fatty liver and pancreatic β-cell dysfunction in a general population. Participants in the study were 489 community-dwelling Japanese adults. Using the fatty liver index (FLI), the extent of fatty liver was estimated. After all, candidates were divided into three groups – low (FLI <30), moderate (30 ≤ FLI <60) or high (FLI ≥ 60) degree of fatty liver – serum proinsulin levels transformed into natural logarithms were compared among the three groups. In the high FLI group, logarithm (proinsulin) was significantly higher than in the moderate and low groups, and it was significantly higher in the moderate group than in the low group after adjustment for age and gender. In the high FLI group, logarithm (proinsulin) was significantly higher than in the low FLI group after adjustment for age and gender, independent of BMI. Regardless of serum insulin levels, a similar pattern was observed. According to this cross-sectional study, the degree of fatty liver was positively linked to proinsulin level, regardless of the presence of obesity or hyperinsulinemia, indicating that fatty liver reflects pancreatic β-cell dysfunction.