Association between serum liver enzymes and all-cause mortality: The Japan Public Health Center-based Prospective Study.
The association of serum liver enzyme levels with all-cause mortality in individuals without hepatitis B virus or hepatitis C virus infection is inconsistent. We aimed to investigate all-cause and non-liver disease mortality according to levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) stratified by hepatitis virus infection status in a Japanese cohort. Participants were 7243 men and 13 513 women aged 40-69 years at the baseline survey in 1993-1994. Multivariate-adjusted hazard ratios of death from the baseline health check-up to December 2012 were calculated with a Cox proportional hazards model controlling for potential confounding factors. During follow-up, 2235 deaths in men and 1901 deaths in women were identified. All serum liver enzymes were associated with all-cause mortality in each sex and hepatitis virus infection status. In participants without infection, those with more than twice the upper level of normal (ULN), which was defined as 30 IU/L for AST and ALT and 50 IU/L for GGT, had a higher risk of non-liver disease mortality compared to those below the ULN (HR 1.69; 95% confidence interval 1.13-2.53, 1.49; 1.02-2.18, 1.39; 1.11-1.73, 1.72; 1.08-2.74 and 1.72; 1.10-2.69 for AST, ALT, and GGT in men and AST and GGT in women, respectively), except for ALT in women. In participants without hepatitis virus infection, serum liver enzyme levels were positively associated with all-cause mortality. Similar associations were also found for non-liver disease mortality.