Associations of serum aminotransferase and the risk of all-cause and cause-specific mortality in Chinese type 2 diabetes: a community-based cohort study

OBJECTIVE: Investigating the associations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with all-cause, cardiovascular disease (CVD) and cancer mortality in a large cohort of community-dwelling patients with type 2 diabetes mellitus (T2DM). DESIGN: Community-based prospective cohort study conducted between 2013 and 2014. SETTING: 44 selected townships in Changshu and Huai’an City, Jiangsu province, China. PARTICIPANTS: 20340 participants with T2DM were recruited in Jiangsu province, China. METHODS: We use Cox proportional hazard models to estimate the HR and 95% CIs of associations of serum ALT and AST levels with all-cause and cause-specific mortality. Restricted cubic splines were used to explore the dose-response relationships between ALT and AST levels with mortality. RESULTS: ALT and AST levels were inversely associated with CVD mortality, compared with the lowest quintile (Q1), the multivariable HRs of the highest quintile (Q5) was 0.82 (95% CI: 0.66 to 1.01, p for trend=0.022) and 0.78 (95% CI: 0.63 to 0.96, p for trend=0.022), respectively. Furthermore, the HRs for ALT levels in all-cause mortality were 0.90 (95% CI: 0.79 to 1.01, p for trend=0.018), and the HRs for AST levels in cancer mortality were 1.29 (95% CI: 1.02 to 1.63, p for trend=0.023). Stronger inverse effects of ALT and AST levels on all-cause mortality were observed in the older subgroup and in those with dyslipidaemia (all p for interaction <0.05). Further analysis based on gender showed that the associations between serum aminotransferases and the mortality risk were more significant in women and substantially attenuated in men. CONCLUSION: Our findings suggested patients with T2DM with lower levels of ALT and AST had an increased risk of CVD mortality, which needs confirmation in future clinical trials.