Prevalence and risk factors for prolonged QT interval and QT dispersion in patients with type 2 diabetes

Abstract

AimsProlonged 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.ResultsPrevalence 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).ConclusionsAlthough 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.

The effect of glucose variability on QTc duration and dispersion in patients with Type 2 Diabetes Mellitus

“…These findings were in accordance with the previous studies as the prevalence of high QTc duration and QTc dispersion ranged from 15.4 to 67% for QTc and from none to 33% for QTc dispersion 23-26. Ninkovic et al mentioned about the GV as a risk factor of prolonged QT and QT dispersion 27. They used the mean amplitude of glycemic excursion (MAGE) to represent the GV.…”

“…Li et al claimed that microalbuminuria was the only diabetic microvascular complication related to QTc prolongation other than retinopathy and nephropathy 26. On the other hand Ninkovic et al showed a significantly higher prevalence of retinopathy and polyneuropathy among patients with high QTc duration 27. In our study, we couldn’t find any relation between microvascular complications and QT parameters.…”

Pro- and Antiarrhythmic Actions of Sulfonylureas: Mechanistic and Clinical Evidence

“…[53] Recently, Ninkovic et al found that sulfonylurea exposure was an independent risk factor for QT interval prolongation in persons with T2DM. [55] In contrast, Tentolouris et al found that neither QT interval duration nor dispersion was significantly longer in sulfonylurea vs. insulin users. [56] Yet, the latter two studies comingled users of different sulfonylureas into a single exposure group.…”

Cardiac autonomic neuropathy in patients with diabetes mellitus: current perspectives

“…QT prolongation is associated with cardiac arrhythmias and sudden death 77. Its pathogenesis is multifactorial, but includes an imbalance in cardiac sympathetic innervation and left-ventricular hypertrophy, as is often seen in CAN 78…”