Association between alanine aminotransferase and all-cause mortality rate: Findings from a study on Japanese community-dwelling individuals

Abstract

Background: This study examined the relationship between survival prognosis and alanine aminotransferase (ALT), a critical factor contributing to aging-related health and mortality. The research is based on a follow-up study with 6- and 10-year intervals. Methods: The participants included 1,610 males (63 ± 14 years old) and 2,074 females (65 ± 12 years old) who were part of the Nomura cohort study conducted in 2002 (first cohort) and 2014 (second cohort). The multivariable-adjusted hazard ratios (HRs) of death between the baseline health checkup and the end of the follow-up periods were estimated using a Cox proportional hazards model, controlling for potential confounding factors. Results: The follow-up survey revealed 180 male deaths (11.2% of male participants) and 146 female deaths (7.0% of female participants). The univariate Cox regression analysis showed a significant increase in the HRs of all-cause mortality with decreasing ALT levels (p < 0.001). Furthermore, compared with individuals with ALT levels of 20–29 IU/L, the multivariable-adjusted HRs (95% confidence interval) for all-cause mortality were 2.73 (1.59–4.70) for those with ALT levels <10 IU/L, 1.45 (1.05–2.00) for those with ALT levels of 10–19 IU/L, and 1.63 (1.05–2.53) for those with ALT levels ≥30 IU/L. Conclusions: Our findings show that abnormally low ALT levels and high within the normal range were related to all-cause mortality in Japan's community-dwelling individuals. Especially, ALT activity may be an important biomarker for predicting the long-term survival of older adults.