Objectives: The aim of this study was to determine the relationship between 25-hydroxyvitamin D (25(OH) D) level and blood pressure (BP) in Saudi women and to assess the effect of BMI, as a measure of adiposity, on this relationship.
Methods: Three-hundred and three apparently healthy Saudi women (2040 years old) were randomly selected for this cross-sectional study. All women signed an informed consent and the study was approved by the Ethical Committee. BP was measured using an automated BP monitor (BPTru) following a standardized protocol. Anthropometric measures were taken and fasting blood samples were obtained for the determination of serum 25(OH) D and parathyroid hormone (PTH). Both hormones were determined by chemiluminescence immunoassay method (DiaSorin, Italy). Linear regression models were used to determine the independent correlation between 25(OH) D level and BP.
Results: Vitamin D deficiency was highly prevalent among the studied women with 96.7% having 25(OH) D levels< 50 nmol/l and 70% having levels <25 nmol/l. Linear regression analysis showed that 25(OH) D concentrations were negatively correlated to both systolic (β=− 5.962, P=0.001) and diastolic BP (β=−3.483, P=0.029) in models adjusted for age and PTH. When adding BMI to the model, this correlation was attenuated for the systolic BP (β=−4.848, P=0.005), but became stronger for the diastolic BP (β=−4.291, P=0.004).
Conclusion: In young Saudi women, the correlation between 25(OH) D and BP is independent of BMI. Since both vitamin D deficiency and obesity are prevalent among Saudi women, proper measures for the management of these health problems have to be taken in order to prevent future hypertension and other cardiovascular events. Longitudinal studies to confirm these findings, and intervention studies to assess the BP lowering effects of 25(OH) D on hypertensive and obese subjects are needed.
17 May 2014 - 20 May 2014