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Hypertension reduced 6.8 mmHg with 3,000 IU of vitamin D daily – RCT May 2012

VITAMIN D SUPPLEMENTATION DURING WINTER MONTHS REDUCES CENTRAL BLOOD PRESSURE IN PATIENTS WITH HYPERTENSION

22nd European Meeting on Hypertension and Cardiovascular Protection. April 2012
T. Larsen1, F. Mose1, E. Pedersen 1, O. Aagaard 2.
I Department of Medical Research, Holstebro Hospital, Holstebro, Denmark,
2 Department of Medical Biochemistry, Holstebro Hospital, Holstebro, Denmark
Oral 7A.02

Objective: In the northern hemisphere vitamin D deficiency is highly prevalent during winter months, and observational studies have associated hypertension with poor vitamin D status. We tested the hypothesis that vitamin D supplementation in the winter lowers blood pressure (BP) in patients with hypertension.

Design: Randomized, placebo-controlled, double-blind study.

Method: 130 patients with hypertension were randomized to a daily oral dose of 75 ug cholecalciferol or placebo for 20 weeks. The study population consisted of Caucasians residing in Denmark at the 56th northern latitude. Baseline examinations took place from October to November where cutaneous vitamin D synthesis is absent. Primary endpoints were 24-h ambulatory BP, pulse wave velocity (PWV) and central BP obtained by applanation tonometry. Other endpoints were p-25(OH)D, p-Ca++, p-iPTH and components of the renin-angiotensin system. Plasma concentrations of renin, angiotensin II and aldosterone were measured using RIAs. Data were analyzed using unpaired t-test and Mann-Whitney test when appropriate.

Results: 112 patients (mean age 61 ± 10) with a baseline p-25(OH)D of 57 ± 26 nmol/l completed the study. Compared with placebo, cholecalciferol caused a significant increase in p-25(OH)D (62 nmol/l, p < 0.001) and p-Ca++ (0.01 mmol/l, p < 0.05), and a significant suppression of p-PTH (0.97 pmol/l, p < 0.001). No significant differences were observed in 24-h ambulatory BP.

However, in patients with p-25(OH)D <75 nmol/l (n = 92), the cholecalciferol group showed a borderline reduction in both systolic BP (3.7 mmHg, p = 0.08) and diastolic BP (2.7 mmHg, p = 0.02) compared to placebo.

Furthermore, in all patients, central systolic and diastolic BP was reduced 6.8 mmHg (p = 0.007) and 1.7 mmHg (p = 0.15), respectively, compared to placebo. No statistically significant difference between groups was observed in pulse wave velocity.

Conclusion: In hypertensive Caucasians residing at the 56th northern latitude, 75 ug of cholecalciferol daily during winter months caused a significant reduction in central systolic blood pressure. In a sub-analysis of patients with p-25(OH)D <75 nmol/l, a marginal reduction in both systolic and diastolic 24-h ambulatory BP was observed.
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Note: same authors also presented this information as:
ANTIHYPERTENSIVE EFFECT OF CHOLECALCIFEROL DURING WINTER MONTHS IN PATIENTS WITH HYPERTENSION
49th ERA-EDTA CONGRESS, MAY 24-27, 2012, PARIS, France
Introduction and Aims: Vitamin D deficiency is highly prevalent globally. In Northern Europe UVB-induced cutaneous cholecalciferol synthesis comes to a halt in early October, and as a result 25- hydroxy-vitamin D (25(OH)D) levels decrease during winter months. Observational studies have associated low 25(OH)D levels with a higher risk of hypertension. However, randomized controlled trials are few and inconsistent. The aim of this study was to test the hypothesis that vitamin D supplementation in the winter lowers blood pressure (BP) in patients with hypertension.

Methods: We studied the effect of 75 ?g (3000 IU) cholecalciferol daily for 20 weeks in a randomized, placebo-controlled, double-blind study in 130 patients with hypertension. The study population consisted of Caucasians residing in Denmark at the 56th northern latitude. Baseline examinations took place in October and November, and follow-up was conducted no later than end of March. Primary endpoints were changes in 24-hr ambulatory BP (ABP), pulse wave velocity (PWV) and central BP obtained by applanation tonometry (SphygmoCor®). Other endpoints were changes in p-25(OH)D, p-Ca++, p-iPTH and components of the renin- angiotensin system. Plasma concentrations of renin, angiotensin II and aldosterone were measured using RIAs.

Results: 112 patients (mean age 61±10) with a baseline p-25(OH)D of 57±26 nmol/l completed the study. Compared with placebo, cholecalciferol caused a significant increase in p-25(OH)D (62 nmol/l, p<0.001) and p-Ca++ (0.01 mmol/l, p<0.05), and a significant suppression of p- iPTH (0.97 pmol/l, p<0.001). A non-significant reduction in systolic and diastolic ABP was observed. In patients with p-25(OH)D<75 nmol/l (n=87) at baseline, this effect was augmented (systolic ABP: 3.7 mmHg, p=0.08; diastolic ABP: 2.7 mmHg, p=0.02). Central systolic and diastolic BP was reduced 6.8 mmHg (p=0.007) and 1.7 mmHg (p=0.15), resp., compared to placebo. No statistically significant difference between groups was observed in pulse wave velocity.

Conclusions: In hypertensive Caucasians residing at the 56th northern latitude, 75 ?g of cholecalciferol daily during winter months caused a significant reduction in central systolic blood pressure. Cholecalciferol also tended to lower both systolic and diastolic 24-hr ABP, especially in patients with baseline p-25(OH)D below 75 nmol/l.
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