Aspartate/alanine aminotransferase ratio and development of chronic kidney disease in non-diabetic men and women: a population-based longitudinal study in Kagawa, Japan.

Background: The relationship between serum aspartate/alanine aminotransferase ratio (AST/ALT) and subsequent development of chronic kidney disease (CKD) in non-diabetic Asian adults has not yet been fully investigated in longitudinal studies.

Methods: The study included all middle-aged and older non-diabetic Japanese citizens who received health check-ups in Zentsuji, Kagawa, Japan (1998-2023). AST/ALT was classified into three categories: < 1.0 (reference), 1.0- < 1.5, and ≥ 1.5. CKD was defined as an estimated glomerular filtration rate of < 60 mL/min/1.73 m². The Weibull accelerated failure time model was used to examine the association between AST/ALT categories and subsequent CKD onset because the proportional hazards assumption was violated.

Results: Of 6309 men and 9192 women, 2966 men and 4395 women remained in the final cohort. After a mean follow-up of 7.50 years for men and 8.34 years for women, 33.7% of men and 34.0% of women developed CKD. Women had higher AST/ALT than men. In women, a dose-response relationship was observed, with a 9% shorter survival time to CKD onset for AST/ALT ≥ 1.5 compared with AST/ALT < 1.0. In contrast, men had a shorter survival time to CKD onset by point estimates, but the 95% confidence intervals crossed 1 in all models.

Conclusions: In this study comparing the risks of CKD development in non-diabetic men and women by AST/ALT levels, a dose-response relationship was only observed in women. Differences in the distribution of AST/ALT by sex may have affected the results. Therefore, in non-diabetic Japanese women, AST/ALT may be used as an indicator of future CKD development.