Abstract

BACKGROUND
A prolonged QT interval is considered as an indicator of an increased risk of coronary heart disease, malignant ventricular arrhythmias and/or sudden death. QT interval prolongation has been reported to be a common finding in patients with obesity and diabetic autonomic neuropathy and it is well known that both leptin and insulin stimulate sympathetic activity. The waist to hip ratio and the plasma insulin levels were recently reported to be correlated with the QT intervals and the sympathovagal balance. The aim of the present study was to evaluate the association of the features of metabolic syndrome and the QT interval in type 2 diabetic patients. METHODS: We studied 114 type 2 diabetes(45 males and 69 females). The QT intervals were measured by a software program and then the QTc was calculated. The fasting glucose, total cholesterol, triglyceride and high-density lipoprotein(HDL)-cholesterol, HbAIC and Cpeptide were measured. All the patients received clinical tests for cardiovascular autonomic dysfunction by the Ewing's method. RESULTS: A significant difference was found in the mean QT interval between the patients with an autonomic score>=1 and the patients who were without cardiac autonomic neuropathy(autonomic score=0). On Pearson's simple regression analysis, the QT interval showed positive correlations with the BMI, fasting C-peptide, systolic blood pressure(sBP), and age. The QT interval also showed negative correlation with the HDL-cholesterol. The associations of the QTc with triglyceride, fasting glucose, and the autonomic score did not reach statistical significance. On the multiple regression analysis, the QT interval was independently correlated with BMI, systolic BP and HDL-cholesterol but not with the other variables that we tested(c-peptide, autonomic score, diastolic blood pressure, glycated hemoglobin, triglyceride and cholesterol). CONCLUSION: Our results suggest that a variety of features of metabolic syndrome are associated with QT interval prolongation in the type 2 diabetic patients

• Keywords: QT interval;Diabetic autonomic neuropathy;Metabolic syndrome;Type 2 diabetes;