Evaluation of the Relationship between Serum 25-Hydroxy Vitamin D and Hypertension in Hamadan, Iran-A Case Control Study.

INTRODUCTION: Hypertension or high blood pressure is one of the main reasons of fatality in the world. The role of vitamin D in developing hypertension has not been proved yet. Some studies have shown positive correlation between low serum vitamin D level and hypertension. Due to this fact, recognising hypertension risk factors such as potential impact of low serum vitamin D level seems to be required.

AIM: This study was conducted to evaluate potential impact of serum vitamin D level on hypertension.

MATERIALS AND METHODS: This case-control study had 188 subjects including 55 cases suffering from hypertension and 133 controls with normal blood pressure in Hamadan, Iran. After taking the medical history and physical examination, 5 cc of their blood was taken to measure their serum 25-Hydroxyvitamin D [25(OH)D] level through ELISA test. Data analysis was done by version 16.0 of SPSS software and used independent sample t-test and Chi-square test for related comparisons.

RESULTS: Mean and standard deviation of serum 25(OH)D level in patients suffering from hypertension was 13.10±9.7 ng/ml and in control group was 20.87±10.34 ng/ml. This variance was statistically significant (p<0.001). Mean serum 25(OH)D level in both case and control groups was measured after gender and age stratification. Mean serum 25(OH)D level in cases and controls was 13.12±11.4 ng/ml and 21.38±11.47 ng/ml in males (p=0.016) and 13.10±9.91 ng/ml and 19.19±10.55 ng/ml (p=0.004) in females, respectively. Mean serum 25(OH)D level in under 50-year-old was 10.82±8.73 ng/ml and 20.07±11.17 ng/ml in cases and controls respectively (p<0.001). In over 50-year-old, there was no significant relationship between mean serum 25(OH)D and blood pressure levels (p>0.05).

CONCLUSION: According to this study, reverse relationship between serum 25(OH)D and blood pressure levels was seen.