Vitamin D as a Marker of Arterial Calcification and Cardiovascular Risk in Children on Regular Hemodialysis

Background: Vitamin D is essential for promoting calcium absorption in the gut and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and prevent hypocalcemic tetany. It has other roles including modulation of neuromuscular and immune function and reduction of inflammation. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. Decreased serum levels of vitamin D have been related to arterial stiffening and vascular calcifications in haemodialysis (HD) patients but the pathophysiology of this association is not yet clear.
Objectives: The aim of this study is to evaluate the relationship between vascular calcifications, cardiovascu-lar risk factors especially (left ventricular mass index) and 25-hydroxyvitamin D3 [25(ОН)D3] and 1,25-dihydroxyvitamin D3 [1,25(ОН)2D3] serum levels in children with chronic renal failure on regular haemodialysis.
Methods: The study was conducted on 30 children regularly haemodialyzed 3 times weekly and 3 hours pert session by polysulfone membrane using citrate dialysate. All cases were subjected to detailed history taking, thorough clinical examination, laboratory investigations including assessment of serum 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 by thin layer chromatography. Echocardiography was done for evaluation of left ventricular mass index (LVMI) by Devereux's formula.
Results: There was a significant and a highly significant negative correlation between left ventricular mass index (LVMI) and 25-ОН and 1-25(OH)2 respectively. Increased left ventricular mass Index in patients without one alpha supplementation was found.
Conclusion: We conclude that deficiency of [25(ОН)D3] and [1,25(ОН)2D3] is prevalent in hemodialyzed children and is associated with cardiovascular risk.