Effect of obesity on P-wave dispersion and QT dispersion in women

Abstract

The aim of this study was to investigate the effect of obesity on dispersion of P-wave duration and QTc interval in obese women. Forty-two obese women (Body mass index (BMI)=40+/-3 kg/m(2), mean age 45+/-9 years) and compared age-matched (BMI=22+/-1 kg/m(2), mean age 41+/-6 years) twenty-five non-obese women were included in our study. Maximum and minimum P-wave duration, P-wave dispersion (difference between the maximum and the minimum P-wave duration), maximum and minimum QTc interval, and QTc dispersion (the difference between the maximum and the minimum QTc interval) were measured from 12-lead ECG. ECG's were transferred to a personal computer via a scanner and then used for magnification of 400 times by Adobe Photoshop software. There was significant difference in BMI (40+/-3 vs 22+/-1 kg/m(2), P<0.001, respectively) between obese and non-obese women. Obese women had higher Max. P-wave duration (116+/-11 vs 94+/-14 ms, P<0.001), P-wave dispersion (51+/-15 vs 26+/-11 ms, P<0.001), Max. QTc interval (449+/-38 vs 419+/-30 ms, P<0.001) and QTc dispersion (57+/-23 vs 38+/-15 ms, P<0.001) compared to non-obese women. A significant correlation was found between BMI and Max. P-wave duration (r=0.584, P<0.001), P-wave dispersion (r=0.621, P<0.001), Max. QTc interval (r=0.410, P<0.001), and QTc dispersion (r=0.429, P<0.001). In the linear regression analysis, compared to co-morbidity factors such as age, hypertension, diabetes mellitus and smoking, there was significant association between only BMI and electrocardiographic values (P-wave and QTc dispersion). We concluded that obesity caused significant increase in P-wave and QTc dispersion. Therefore, obese women may not only be under the risk of ventricular arrhythmias, but also they may under the risk of atrial arrhythmias.