Study of QT interval prolongation in asymptomatic type-2 diabetes mellitus patients with and without microalbuninuria

Abstract

QT interval abnormalities are the best predictors of cardiovascular deaths. Microalbuminuria is an independent marker for cardiovascular disease in diabetes mellitus. Hence QT interval abnormalities in diabetics with or without microalbuminuria were evaluated in this study. To study QT interval abnormalities in asymptomatic type 2 diabetic patients with or without microalbuminuria. : Open label controlled study with 214 subjects of either sex. Group A healthy subjects (n=100), group B asymptomatic, type 2 diabetics with no clinical evidence of cardiac disease. Group B subdivided into B with microalbuminuria (n=62), Bwithout microalbuminuria (n=52). Corrected QT interval (QTC), microalbuminuria, and blood pressure were measured for all subjects. QTC was calculated by using Bazzet's formula. QTC more than 440msec was considered prolonged. QTC was within normal range in diabetic patients(415+25msec). Highly significant (p<0.0001) prolongation was observed in diabetics, compared to healthy subjects. Both B(p<0.0001) and B(p<0.001) groups showed a significant increase in QTC than in healthy subjects. Among Band Bgroups QTC was not statistically significant. Prolongation of QTC is indicative of CAN. CAN is often under-recognised and undiagnosed cardiac complication.QTC was more in asymptomatic type 2 diabetics irrespective of microalbuminuria compared to healthy individuals, though values were within normal range. This denotes high risk for future cardiovascular complications in diabetic patients.