Effects of serum vitamin D level on ventricular repolarization in children and adolescents

Low levels of vitamin D are known to increase cardiovascular mortality due to different risks. We aimed to examine whether low vitamin D levels in children and adolescents cause ventricular repolarization changes.

Sixtyseven healthy cases aged between 3.5 and 17 years were included. According to levels of vitamin D, cases were grouped as sufficient (n=44), insufficient (n=13) and deficiency (n=10). Ventricular repolarization parameters were measured manually.

Levels of vitamin D were different for cases with insufficiency and deficiency compared to sufficiency ones (102±54.9 vs 24.4±7 ng/ml, p<0.001 and 102±54.9 vs 16.6±8.3 ng/ml, respectively, p<0.001). In the insufficient group the following parameters were different from sufficient group: QTmean (357.8±25.3 vs 332±29.9 ms, p=0.012), JTc (310.8±20.2 vs 331.6±21 ms, p=0.005) and Tpe/QT (0.2±0.02 vs 0.22±0.02, p=0.02). It was found that the level of serum vitamin D correlated with JTc (r=-0.37, p=0.002), Tp-e (r=-0.29, p=0.015) and Tp-e/QT (r=-0.24, p=0.047). In the linear regression analysis, it was found that dropping level of vitamin D below normal was an independent risk factor for prolonged duration of JTc (p=0.015).

Decline in vitamin D levels causes ventricular repolarization anomaly. As the decrease in vitamin D levels deepens, repolarization times become longer. These results could indicate that decrease in vitamin D levels can increase sensitivity to ventricular arrhythmias (Tab. 3, Ref. 45). Text in PDF www.elis.sk Keywords: adolescent, arrhythmia, child, vitamin D, ventricular repolarization.