AbstractBackgroundThere are limited studies about the association between nonalcoholic fatty liver disease (NAFLD) and corrected QT interval (QTc) prolongation worldwide.HypothesisTherefore, we designed the current study to determine this association in a large cohort of a generally healthy population.MethodsWe analyzed the data of 4603 individuals aged 35–70 who participated in the Fasa Cohort Study (FACS). Based on 12‐lead electrocardiograms, QT intervals were calculated and corrected by Bazzet's formula. A QTc interval of more than 430 ms in men and 450 ms in women was considered prolonged. The Fatty Liver Index was used to identify the participants with NAFLD.ResultsOf all participants, 1550 (33.6%) met the NAFLD criteria. In subjects of both genders with NAFLD, the mean values of the QTc interval were considerably higher than in those without NAFLD (p< .001). After adjusting for a wide range of confounders, including age, gender, smoking status, physical activity, total cholesterol, high‐density lipoprotein‐cholesterol levels, diabetes, and hypertension status, in linear regression analysis, the standardized β coefficient of QTc interval among participants with NAFLD was 2.56 ms (95% confidence interval [CI]: 0.49–4.64). After controlling the same confounders, the odds ratio of NAFLD for a prolonged QTc interval in men was 1.47 (95% CI: 1.18–1.84;p< .001) and in women was 1.39 (95% CI: 1.15–1.68;p< .001) using logistic regression analysis.ConclusionsNAFLD was a risk factor for QTc interval prolongation. Awareness about the risk of NAFLD in increasing the potential cardiac arrhythmias should be raised to lower cardiac mortality.