Association of vitamin D deficiency with ventricular repolarization abnormalities

BACKGROUND Vitamin D is involved in cardiac contractility and myocardial calcium hemostasis, and vitamin D deficiencies are known to cause various cardiovascular disorders and have been linked with sudden cardiac death. AIMS The aim of the study was to evaluate repolarization distribution, represented by QT interval, corrected QT interval (QTc), QT dispersion, Tpeak-to-Tend (Tp-e) interval, Tp-e/QTc ratio, JT interval, JT dispersion, and Tp-e/JTpeak ratio in children with vitamin D deficiency. Moreover, we aimed to determine the relationship between ventricular repolarization anomalies and vitamin D deficiency. METHODS The study included 50 adolescent patients with vitamin D deficiency (vitamin D <20 ng/ml), 50 adolescent patients with vitamin D insufficiency, and 50 age-matched controls (vitamin D level >30 ng/ml). QTc duration, QT dispersion, JTpeak duration, JT dispersion, Tp-e, Tp-e/JTpeak ratio, and Tp-e/ QTc ratio were recorded on electrocardiogram. RESULTS Patients with vitamin D deficiency or insufficiency had longer Tp-e interval (P <0.001), while Tp-e/QTc and Tp-e/Tpeak ratios were found to be increased in the same group of patients (P = 0.005 and P <0.001, respectively). QT dispersion and JT dispersion were higher in the deficient group when compared with the other groups (P= 0.045 and P= 0.02, respectively). CONCLUSIONS The present study, conducted in a pediatric population, is the first in the current literature to assess the relationship between ventricular repolarization anomalies and vitamin D deficiency.