BackgroundElectrocardiogram (ECG) is widely used to screen cardiac diseases. To date, no large population study has provided estimates of the prevalences of ECG findings in China. We aim to investigate the prevalences and associated factors of ECG abnormalities in a general population of Chinese adults.MethodsECG data were obtained from 34,965 participants in the 2007-2008 China National Diabetes and Metabolic Disorders Study. ECG abnormalities were classified according to the Minnesota coding (MC) criteria. Prevalences of variant ECG abnormalities were calculated. The associations between ECG abnormalities and gender, age and other risk factors for cardiovascular diseases (CVD) were analyzed by multivariate logistic regression test.ResultsThe prevalences of major arrhythmias were 1.70, 2.37 and 1.04% in the whole population, men and women, respectively. Atrial fibrillation/flutter was found in 0.35% of men and 0.20% of women. ST depression and T abnormalities accounted for 10.96, 7.54 and 14.32% in the whole population, men and women, respectively. Independent of gender and other CVD risk factors, older age significantly increased the odds of having atrial fibrillation/flutter, complete left bundle branch block, complete right bundle branch block, sinus tachycardia, atrial/junctional/ventricular premature beats, ST depression and T abnormalities, tall R wave left, left/right atrial hypertrophy, left axis deviation and low voltage. Hypertension, overweight, obesity and hypercholesterolemia all independently increased the odds of having ST depression and T abnormalities. History of cardiovascular/cerebrovascular diseases was positively associated with major arrhythmias, ST depression and T abnormalities and tall R wave left.ConclusionsThis study provides estimates of the prevalences of ECG findings in a large population of Chinese adults. Gender, age, CVD risk factors and history of cardiovascular/cerebrovascular diseases were significantly associated with ECG abnormalities.