Evaluation of Vitamin D Level and its Correlation to Vascular Calcification in Hemodialysis Patients

Introduction: Compared with the general population, hemodialysis patients are at increased risk of vascular calcification, which in turn is associated with an increased risk of mortality. Regarding the role of vitamin D in bone formation, regulation of calcium, phosphate and iPTH level and correlation of these variables in survival, this study was performed to evaluate the vitamin D serum level and its correlation with vascular calcification in hemodialysis patients.

Methods: In this analytical, cross-sectional study one hundred hemodialysis patients who referred for dialysis to Shahid Mohammadi hospital in Bandar Abbas were evaluated in 2011. Patients older than 15 years on regular hemodialysis (at least dialyzed for 3 months) were selected as study population and patients who had undergone parathyroidectomy were excluded. Variables such as age, sex, BMI, hemodialysis duration, vitamin D, ferritin, PTH, calcium, phosphate, hemoglobin and CRP were specified. Vascular calcification in lateral x-ray of abdomen determined based on scoring system to abdominal aortic calcification in front of lumbar spines (L1-L4). Data analysis was performed by SPSS software and t-test and Chi-Square test.

Results: In this study 25% of hemodialysis patients had vitamin D deficiency that in male and female were similar. The prevalence of vascular calcification based on plain lateral abdominal x-ray was 52. 2%, that was included 55% women and 45% men. No relationship was found between vascular calcification and Vitamin D serum level, but there was positive correlation between vascular calcification and patients' age, also higher level of serum Ferritin was detected in patients with higher Vitamin D level (P=0.001).

Conclusion: In summary our study results showed the low prevalence (25%) of Vitamin D deficiency in hemodialysis patients as compared to similar studies in other countries that may be related to geographical situation of the region. No relationship was found between Vitamin D serum level and vascular calcification. In this study the vascular calcification has been evaluated with plain x-ray that is not a high sensitive test. For measuring vascular calcification our recommendation is to perform more sensitive tests