Impaired fasting glucose, diabetes mellitus, and cardiovascular disease risk factors are associated with prolonged QTc duration. Results from the Third National Health and Nutrition Examination Survey

Background Impaired glucose tolerance and diabetes mellitus have been associated with a prolonged QT interval among select populations. However, these associations remain unclear among the general population. Methods We examined these relationships using data from 5833 adults aged 40-90 years from NHANES III (1988-1994). Univariate differences in cardiovascular disease (CVD) risk factors were examined across tertiles of heart rate corrected QT (QTc). The association between glucose intolerance, CVD risk factors and a prolonged QTc (greater than or equal to0.440 s) was also assessed with logistic regression adjusting for age, race, gender, education, and heart rate. Results Prolonged QTc was observed among 22.0% of persons with normal glucose tolerance (NGT), 29.9% of those with impaired fasting glucose (IFG), and among 42.2% of persons with diabetes. Hypertension, serum cholesterol, obesity, heart rate, and fasting C-peptide and serum insulin levels were associated with prolonged QTc (all: P less than or equal to0.05). After multivariate adjustment, persons with IFG were 1.2 times (95% CI=0.7-2.0) as likely and persons with diabetes 1.6 times (95% CI=1.1-2.3) as likely to have a prolonged QTc as persons with NGT. In addition, persons with diabetes and two or more additional CVD risk factors were 2.3 times (95% CI=1.3-4.0) as likely to have a prolonged QTc as persons with NGT and no CVD risk factors after multivariate adjustment. Conclusion Diabetes was associated with an increased likelihood of prolonged QTc independent of age, race, gender, education, and heart rate. In addition, persons with diabetes and multiple CVD risk factors were more likely to have a prolonged QTc than those with NGT and no additional risk factors, suggesting that these persons may be at increased risk for cardiac arrhythmia and sudden death. J Cardiovasc Risk 2001,8:227-233 (C) 2001 Lippincott Williams & Wilkins.