Elevated alanine aminotransferase levels predict mortality from cardiovascular disease and diabetes in Koreans

Metabolic syndrome is associated with increased cardiovascular morbidity and mortality. Nonalcoholic fatty liver disease (NAFLD) is closely associated with metabolic syndrome. This study investigated the relationship between elevated alanine aminotransferase (ALT) levels, as a proxy marker of NAFLD, and death from cardiovascular disease (CVD) or diabetes in a Korean population.

The study population consisted of 37,085 patients who underwent health examinations at the Health Promotion Center of the Asan Medical Center, Seoul, Korea, in 2000 and 2001. Individuals with viral hepatitis or alcoholic liver disease were excluded from the study. The relationship between baseline ALT levels and CVD- or diabetes-related mortality was determined for a median period of 5.0 years.

A total of 407 deaths occurred during the follow-up period, with 91 deaths resulting from CVD or diabetes. The multivariate relative risk (RR) and 95% confidence interval (CI) for CVD- or diabetes-related mortality in patients with ALT levels >40IU/L were 2.26 (1.22-4.19). The multivariate RR and 95% CI for CVD- or diabetes-related mortality in patients with the highest quartile of ALT levels (> or =31IU/L) were 2.28 (95% CI: 1.02-5.08) when the lowest quartile (< or =15IU/L) was used as a reference.

Our findings demonstrate that elevated ALT levels are independently associated with increased CVD- or diabetes-related mortality in Koreans. Thus, elevated ALT levels, as a marker for NAFLD, may serve as a surrogate predictor of CVD- or diabetes-related mortality among the Korean population.