Elevation of serum aminotransferase activity increases risk of carotid atherosclerosis in patients with non-alcoholic fatty liver disease

Background and Aim: Patients with non-alcoholic fatty liver disease (NAFLD) have an increased risk of atherosclerosis and alanine aminotransferase (ALT) is associated with insulin resistance independently of metabolic factors. The aim of the present study was to investigate whether NAFLD patients with ALT elevation had a higher risk of carotid atherosclerosis. Methods: A total of 190 individuals were enrolled from the health management center. Among them, 20 subjects were excluded due to the presence of hepatitis B surface antigen (HbsAg), anti-hepatitis C virus (HCV) and cardiovascular disease. NAFLD was diagnosed by ultrasound examination. Carotid ultrasonography was used to measure maximal intima-media thickness (IMT) of the common carotid artery (CCA) and IMT (mean) > 1.0 mm was defined as the presence of carotid atherosclerosis. Results: NAFLD patients with ALT elevation had increased risk of carotid atherosclerosis than those with normal ALT by Fisher's exact test (P < 0.05). Multivariate analyses showed that serum ALT levels were positively associated with carotid atherosclerosis after adjustment for age, sex, number of metabolic syndrome components or status of metabolic syndrome (OR, 1.44; 95% CI 1.09-1.89; OR, 1.45; 95% CI 1.11-1.91). In addition, the higher the serum ALT levels with every 10 IU/L increment, the greater the risk of carotid atherosclerosis. Conclusions: Serum ALT levels are positively associated with the risk of carotid atherosclerosis in patients with NAFLD, suggesting that serum ALT levels could serve as a surrogate marker of cardiovascular risk in this special clinical setting.