Association of vitamin D deficiency with arterial stiffness in newly diagnosed hypertension.

ABSTRACT

OBJECTIVE: Vitamin D has beneficial effects on vascular endothelial function, blood pressure (BP) and arterial stiffness. Arterial stiffness increases in early-stage hypertensive patients and it is a strong predictor of cardiovascular morbidity and mortality. The purpose of this study was to assess the association between serum 25-hydroxyvitamin D (25-OH D) levels and arterial stiffness in patients with newly diagnosed hypertension. METHOD: Our study included 100 newly diagnosed hypertensive patients (63 male, 37 female and mean age 51.7 ± 10.3 years) without cardiovascular disease, malignancy, chronic kidney disease and diabetes mellitus. Patients were divided into two groups vitamin D deficiency group (<20 ng/ml) and normal vitamin D group (≥20 ng/ml). Twenty-four-hour, daytime and nighttime ambulatory BP readings were recorded. Mobil-O-Graph ARC solver algorithm was used to evaluate arterial stiffness parameters of pulse wave velocity (PWV) (m/s), augmentation index normalized with 75/min heart rate (Alx@75). RESULTS: Patients with vitamin D deficency had higher values of Alx@75 and PWV values (20.9 ± 9 vs. 16.8 ± 6.9, P = 0.018 and 8.37 ± 1.16 vs. 6.9 ± 0.9, P = 0.001, respectively) despite similar 24-hour ambulatory BP monitoring in both groups. Level of serum calcium was significantly higher in vitamin D deficiency group (9.5 ± 0.23 vs. 9.3 ± 0.12, P = 0.007). Nighttime SBP was higher in vitamin D deficiency group (133.2 ± 14.3 mmHg vs. 126.3 ± 17.2 mmHg; P = 0.03) and also, vitamin D deficiency group had non-dipping SBP pattern compared to normal Vitamin D group (P = 0.013). CONCLUSION: Vitamin D deficiency is associated with increased arterial stiffness in newly diagnosed hypertensive patients in terms of increased PWV and Alx@75 values.