The association of liver enzymes with biomarkers of subclinical myocardial damage and structural heart disease

Background & Aims Patients with non-alcoholic fatty liver disease (NAFLD) are thought to be at increased risk of cardiovascular morbidity and mortality. However, the relationships between NAFLD and subclinical myocardial injury or structural heart disease are unknown. Methods We conducted a cross-sectional analysis of 8668 participants from the Atherosclerosis Risk in Communities (ARIC) Study, who showed no clinical evidence of cardiovascular disease. We used levels of liver enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST] and gamma-glutamyl transpeptidase [GGT]), in the context of no history of elevated alcohol consumption as non-invasive surrogates of NAFLD. We used highly sensitive cardiac troponin T (hs-cTnT) and N-terminal pro-Brain natriuretic peptide (NT-proBNP) as biomarkers of myocardial damage and function. Results In this population-based study (mean age 63 years, 60% women, 78% white), higher levels of ALT, AST, and GGT, even within the normal range, were significantly and independently associated with detectable (hs-cTnT >3 ng/L) and elevated (hs-cTnT ≥14 ng/L) concentrations of hs-cTnT. The adjusted odds ratios (95% confidence interval) for elevated liver enzymes (vs. normal levels) with elevated hs-cTnT were: 1.65 (1.28-2.14) for ALT, 1.90 (1.36-2.68) for AST, and 1.55 (1.13-2.12) for GGT. Furthermore, there was evidence for inverse associations of ALT and AST with NT-proBNP. Conclusions Our results suggest that elevated liver enzyme levels in the absence of elevated alcohol consumption may be associated with subclinical myocardial injury. The inverse association between NT-proBNP and both ALT and AST supports the recently described metabolic role of natriuretic peptides.