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. AIM: 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/JTpeak 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). CONCLUSION: 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.