Relationship between non-alcoholic fatty liver disease and cardiac arrhythmia: a systematic review and meta-analysis

Objective We performed a meta-analysis to create a quantitative estimate of the association between non-alcoholic fatty liver disease (NAFLD) and the risk of cardiac arrhythmia (including atrial fibrillation (AF), prolonged QT interval, premature atrial/ventricular contraction [PAC/PVC] and heart block). Methods A literature review was conducted using PubMed, Embase, Web of Science and the Cochrane Library database to identify observational studies of the link between NAFLD and cardiac arrhythmia. Effect sizes were expressed as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs). The method of analysis of AF was also analysed separately, according to the effect estimate (OR or HR). Results Nineteen studies of 7,012,960 individuals were included. NAFLD was independently associated with higher risks of AF (OR 1.71, 95% CI: 1.14-2.57; HR 1.12, 95% CI: 1.11-1.13), prolonged QT interval (OR 2.86, 95% CI: 1.64-4.99), PAC/PVC (OR 2.53, 95% CI: 1.70-3.78) and heart block (OR 2.65, 95% CI: 1.88-3.72). The heterogeneity of the data with respect to AF and prolonged QT was moderate on sensitivity analysis. Conclusions We found a significantly higher risk of cardiac arrhythmia in patients with NAFLD, but the observational design of the studies does not permit conclusions regarding causality.