Evaluation of the effects of insulin resistance on ECG parameters in obese children

- OBJECTIVE: Obese people are at increased risk of arrhythmia and sudden death, even in the absence of heart dysfunction. In-creased insulin resistance, neurohumoral and autonomic changes in obesity can cause atrial and ventricular repolarization abnormalities. This study aimed to investigate the effect on ventricu-lar repolarization parameters and to show the in-creased risk of ventricular arrhythmia in obese children.PATIENTS AND METHODS: The data of 50 obese children aged 2-18 who applied to the Pe-diatric Endocrinology Outpatient Clinic were eval-uated prospectively. In 12-lead ECGs, heart rate, Pmax, Pmin, P-wave dispersion (Pwdisp), QTmax, QTmin, QT dispersion (QTd), QTcmax, QTcmin, QTc interval dispersion (QTcd), Tpeak-Tend inter-val (Tp-e), Tp-e/QT, Tp-e/QTc were calculated elec-tronically. RESULTS: Tp-e time (0.041 +/- 0.004/0.049 +/- 0.015/p=0.018) and Tp parameters were measured in obese children with and without insulin resis-tance. Tp-e/QT ratio was also found to be high (p=0.035). There is a negative correlation between BMI SDS values and QTcmax and QTcmin values in patients with insulin resistance (p=0.015).CONCLUSIONS: In our study, the Tp-e interval and Tp-e/QT ratios, which had been revealed in literature to be more sensitive in demonstrating ventricular arrhythmias, were found to be higher in obese individuals with insulin resistance than in those without insulin resistance. Obese individ-uals with or without insulin resistance should be carefully evaluated in terms of atrial and ventric-ular depolarization and repolarization parameters with 12-lead ECG during their outpatient controls, and annual 24-hour Holter control should be per-formed to detect arrhythmias.