Association of the serum transaminase with mortality among the US elderly population

Considering the inconsistent findings of research into the associations between serum levels of liver enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], and gamma-glutamyltransferase [GGT]) and mortality among elderly people, we aimed to investigate the associations of ALT, AST, GGT, and De-Ritis ratio (DRR, defined as AST/ALT) and all-cause or cause-specific mortality among the US elderly people using National Health and Nutrition Examination Surveys data.

We included 6415 elderly participants (≥ 65 years). Exclusion criteria included positive test for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection at baseline. Multivariable-adjusted Cox regression models calculating hazard ratios (HR) and 95% confidence intervals were developed for each of the liver enzyme measures.

All-cause cumulative mortality was 33.8%, of which 23.8% were cardiovascular disease (CVD) deaths, 15.6% were cancer deaths, and 60.6% were other cause deaths. Adjusted Cox models found increased all-cause mortality risk for low ALT (HR: 1.70), low AST (HR: 1.13), high GGT (HR: 1.25), and high DRR (HR: 1.68). Low ALT and high DRR predicted CVD mortality. Low ALT (HR: 1.91), low AST (HR: 1.16), high GGT (HR: 1.40), and high DRR (HR: 1.76) predicted other cause mortality.

Low ALT and high DRR were associated with increased CVD and cancer mortality. All serum liver enzyme measures were associated with all-cause mortality and other cause mortality in the US elderly population. Further studies may validate these findings in other elderly populations.