Relationship between QT interval and cardiovascular risk factors in healthy young subjects.

A prolongation of QT interval increases the risk for coronary heart disease, ventricular arrhythmias, and sudden death in diabetic patients, after myocardial infarction, and in the elderly. An association between QT prolongation and cardiovascular risk factors has been demonstrated in middle-aged and elderly subjects. Aims of this study were to evaluate the prevalence of a prolonged corrected QT interval (QTc) in a healthy young population (n=170, age 22-25 years, 84 males) and to investigate the association of QTc and QT dispersion (QTd) with cardiovascular risk factors (body mass index, blood pressure, fasting blood glucose and cholesterol, smoking habits, and hypertensive familiarity). A prolonged QTc was observed in 10% of female and 5% of male subjects; in multiple regression analysis, QTc showed a significant positive relationship with blood glucose in females (P=0.04) and systolic blood pressure in male subjects (P=0.03), while QTd was not significantly related with any of the factors. In conclusion, the association between QTc length, glucose levels, and blood pressure is present also in young healthy subjects. QT measurement may represent a useful marker in the screening of young subjects for cardiovascular prevention. Journal of Human Hypertension (2005) 19, 623-627. doi:10.1038/sj.jhh.1001874; published online 19 May 2005.