Independent effect of alanine transaminase on the incidence of type 2 diabetes mellitus, stratified by age and gender: A secondary analysis based on a large cohort study in China

Abstract Background Previous studies have revealed that alanine aminotransferase (ALT) may be one of the risk factors of developing diabetes. We aimed to demonstrate the independent effect of ALT on incident diabetes and to investigate whether the association between ALT and incident diabetes is modified by age and gender in the general Chinese population. Methods The present study was a retrospective cohort study, including 210,051 Chinese adult participants. The primary outcome was developing diabetes. The serum ALT activities were stratified by quintiles. We obtained data from ‘DATADRYAD’ website and used the data for secondary analysis. Results At a median follow-up of 3.0 y, 4144 of 210,051 (1.97%) participants developed diabetes. After adjustment for potential confounders, a significantly higher risk of the incident diabetes (HR: 1.43, 95% CI: 1.25–1.63) was found in participants in the fifth quintile (Q5, ≥31 U/L) compared to those in the first to fourth quintiles (Q1–4) for ALT activities. Among males aged 30 to 40 and 40 to 50 y with the fifth quintile of ALT activity had 2.4- and 1.5-fold increased odds of developing diabetes, respectively, in comparison with those in the lower ALT activities. Among females with age 30 to 40 and ≥ 70 y, the fifth quintile of ALT activity had 4.9- and 2.2-fold increased odds for incident diabetes. Conclusion Our result indicated that the ALT activity was positively associated with the incident diabetes among Chinese persons. Moreover, 30–40 y individuals, whether male or female, with elevated ALT activities had the greatest increased risk for diabetes compared with persons with lower ALT activities in the same age group.