Published in:
Open Access 01-10-2016 | Original Article
Prevalence and risk factors for prolonged QT interval and QT dispersion in patients with type 2 diabetes
Published in: Acta Diabetologica | Issue 5/2016
Login to get accessAbstract
Aims
Prolonged QT interval is associated with cardiac arrhythmias and sudden death. The present study determined the prevalence of prolonged QT interval and QT dispersion and defined their clinical and metabolic predictors in patients with type 2 diabetes.
Methods
Cross-sectional study included 501 patients with type 2 diabetes. A standard 12-lead electrocardiogram was recorded. QT corrected for heart rate (QTc) >440 ms and QT dispersion (QTd) >80 ms were considered abnormally prolonged. QTc ≥ 500 ms was considered a high-risk QTc prolongation. Demographic, clinical and laboratory data were collected. Independent risk factors for prolonged QTc and QTd were assessed using logistic regression analysis.
Results
Prevalence of QTc > 440 ms and QTd > 80 ms were 44.1 and 3.6 %, respectively. Prevalence of high-risk QTc (≥500 ms) was 2 % only. Independent risk factors for QTc prolongation >440 ms were mean blood glucose (β = 2.192, p < 0.001), treatment with sulphonylurea (β = 5.198, p = 0.027), female gender (β = 8.844, p < 0.001), and coronary heart disease (β = 8.636, p = 0.001). Independent risk factors for QTc ≥ 500 ms were coronary heart disease (β = 4.134, p < 0.001) and mean blood glucose level (β = 1.735, p < 0.001). The independent risk factor for prolonged QTd was only coronary heart disease (β = 5.354, p < 0.001).
Conclusions
Although the prevalence of prolonged QTc > 440 ms is significant, the prevalence of high-risk QTc (≥500 ms) and QTd > 80 ms is very low in patients with type 2 diabetes. Hyperglycaemia and coronary heart disease are strong predictors of high-risk QTc.