The effects of vitamin D deficiency on arterial stiffness and conduction system of the heart in pediatric population

Vitamin D is a steroid-structure hormone which is known to have an important role for bone metabolism and neuromuscular functions. Vitamin D is also considered to have positive effects on the conduction system of the heart and reduction reduction of arterial stiffness through enhancing immune functions, performing anti-inflammatory activity and enabling endothelium-mediated vasodilation. Deficiency of Vitamin D still remains as a public health problem in Turkey like in many other regions of the world. This study aims at researching the effects of Vitamin D deficiency on arterial stiffness and the conduction system of the heart in children. 101 children, who had applied to Yüzüncü Yıl University Children Health and Diseases polyclinics between October 2017 and July 2018, were included in our study. All patients were aged between 2 and 18, and none of them had any chronic diseases reported. Patients were classified into 3 groups based on Vitamin D level. Group 1 had Vitamin D value of 0-12 ng/ml (Vitamin D-deficient); Group 2 had value of 12-20 ng/ml (Vitamin D-insufficient); and Group 3 had value of 20 ng/ml or higher (the control group). On application to polyclinics, patients were examined for their body weight, height, and biochemical parameters including 25 hydroxi vitamin D3, Ca, P, alkaline phosphatase (ALP), PTH, glucose, creatinine, cholesterol, HDL, LDL and triglyceride values. Patients‟ systolic and diastolic blood pressure values, heart rates, and electrodiagrams were also evaluated. Arteriel ultrasonographic screenings and CIM thickness measurements were performed for patients. EKG parameters were analyzed in our study in order to evaluate the effects of Vitamin D deficiency on cardiovascular conduction system. Pmax and Pdis values for Vitamin D-deficient group were significantly higher compared to both Vitamin D-insufficient group and the control group (p<0.05). QTmax and QTdis values for Vitamin D-deficient group were also significantly higher than the values for Vitamin D-insufficient group and the control group (p<0.005). In addition, QTcmax value for Vitamin D-deficient group was significantly higher than the values for Vitamin D-insufficient group and the control group (p<0.05). Also, QTcdis value for Vitamin D-deficient group was significantly higher than the value for the control group (p<0.05). No meaningful difference was observed among 3 groups in terms of Tpe, Tpe / QT and Tpe / QTc values (p>0.05). In our study, we found that Vitamin D deficiency significantly prolongs Pmax, Pdis, QTmax, QTdis, QTcmax and QTcdis time intervals. Our study is the first study that attempts to show the relationship between Vitamin D deficiency and arterial stiffness in Turkey‟s pediatric population. We could not find a statistically meaningful association between Vitamin D level and arterial stiffness in our study (p>0.05). In conclusion, we found that Vitamin D deficiency in children imposes a negative effect on the conduction system of the heart, and such an effect is mostly in the form of subclinical exposure in childhood age. On the other hand, we think the association between Vitamin D deficiency and arterial stiffness may manifest itself in a more apparent form with aging. Vitamin D deficiency may result in several negative conditions for cardiovascular health. Thus, all physicians should be cautious with the diagnosis and treatment of Vitamin D deficiency.