The goal of this study was to determine the prevalence of diabetes mellitus (DM), impaired glucose regulation (IGR) and related metabolic disorders (overweight, obesity and hypertension) in a Chinese population (20–74 years old). An additional goal was to investigate the relationship between glucose metabolism and the Minnesota code-indicated major abnormal electrocardiogram (MA-ECG). There were 3960 individuals selected from urban and rural areas of Fujian, China from July 2007 to May 2008 by multistage-stratified sampling. Ultimately, data from 3208 subjects (20–74 years old) were analysed (including physical measurements, blood biochemical analysis, oral glucose tolerance test and 12-lead resting ECG). According to World Health Organization diagnostic criteria, the prevalence rates of DM and IGR were 9.51% (male, 10.08%; female, 9.14%) and 14.40% (male, 14.48%; female, 14.35%) respectively. Newly diagnosed DM was found in 53.44% of the diabetic subjects. Based on the 2000 China census, the age-standardized prevalence rates of DM and IGR were 7.19% (male, 7.74%; female, 6.61%) and 11.96 % (male, 12.35%; female, 11.56%) respectively. The age-standardized prevalence rates of DM and IGR in urban areas (7.74% and 12.97% respectively) were slightly but no significantly higher than in rural areas (6.67%, 10.86%). The prevalence rates of overweight, obesity and hypertension were 25.50%, 3.52% and 28.52% respectively (age- and sex- standardized rates: 23.69%, 3.02 % and 22.45 %). After adjusting for other confounding risk factors, multiple logistic regression analysis showed that DM and impaired glucose tolerance were independent risk factors for MA-ECG. Non-diabetic subjects with increased 30-min plasma glucose (PG) after an oral glucose load had a higher risk of MA-ECG after adjusting for other risk factors, especially in those with normal glucose tolerance but with 30-min PG ≥ 7.8 mmol L−1 (odds ratio = 1.371 [1.055–1.780]). The prevalence rates of DM and IGR as well as other metabolic disorders have increased dramatically in the last decade in China, especially in rural areas, with many undiagnosed cases of DM. Even slightly elevated PG levels may predict early cardiovascular events.