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 assoc iated 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 cardiovasc ular 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 asse ssed with logistic regression adjusting for age, race, gender, education, a nd heart rate. Results Prolonged QTc was observed among 22.0% of persons with normal gluco se tolerance (NGT), 29.9% of those with impaired fasting glucose (IFG), and among 42.2% of persons with diabetes. Hypertension, serum cholesterol, obe sity, heart rate, and fasting C-peptide and serum insulin levels were assoc iated with prolonged QTc (all: P less than or equal to0.05). After multivar iate 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 p rolonged QTc as persons with NGT. In addition, persons with diabetes and tw o or more additional CVD risk factors were 2.3 times (95% CI=1.3-4.0) as li kely to have a prolonged QTc as persons with NGT and no CVD risk factors af ter multivariate adjustment. Conclusion Diabetes was associated with an increased likelihood of prolonge d QTc independent of age, race, gender, education, and heart rate. In addit ion, persons with diabetes and multiple CVD risk factors were more likely t o have a prolonged QTc than those with NGT and no additional risk factors, suggesting that these persons may be at increased risk for cardiac arrhythm ia and sudden death. J Cardiovasc Risk 2001,8:227-233 (C) 2001 Lippincott W illiams & Wilkins.