title: Vitamin D therapy to reduce blood pressure and left ventricular hypertrophy in resistant hypertension: randomized, controlled trial.
abstract: Low 25-hydroxyvitamin D levels are associated with higher prevalent blood pressure. We tested whether high-dose intermittent oral vitamin D therapy could reduce blood pressure and left ventricular mass in patients with hypertension resistant to conventional treatment. We conducted a parallel-group, double-blind, randomized placebo-controlled trial. Patients with supine office blood pressure >140/90 mm Hg on ≥3 antihypertensive agents received 100 000 U oral vitamin D3 or matching placebo every 2 months. Office and 24-hour ambulatory blood pressure, glucose, and cholesterol were measured at baseline, 2, 4, and 6 months; left ventricular mass index was measured by cardiac MRI on a subgroup at baseline and 6 months. The primary outcome was mean 24-hour ambulatory blood pressure at 6 months. A total of 68 participants were randomized, 34 in each group. Mean age was 63 (SD 11) years, mean baseline office blood pressure was 154/84 (13/10) mm Hg, and mean baseline 25-hydroxyvitamin D level was 42 (16) nmol/L. Treatment with vitamin D did not reduce 24-hour ambulatory blood pressure (adjusted treatment effects: systolic, +3 mm Hg; 95% confidence interval, -4 to +11; P=0.33; diastolic, -2 mm Hg; 95% confidence interval, -6 to +2; P=0.29); similar results were seen for office blood pressure. Left ventricular mass index was measured in a subgroup (n=25); no reduction was seen with vitamin D treatment (adjusted treatment effect, +4 g/m(2); 95% confidence interval, 0 to +7; P=0.04). There was no significant change in cholesterol or glucose levels. Thus, 6 months of intermittent, high-dose oral vitamin D3 did not reduce blood pressure or left ventricular mass in patients with resistant hypertension.
authors.affiliation: Ageing and Health, Ninewells Hospital, University of Dundee, Dundee DD1 9SY, United Kingdom. m.witham@dundee.ac.uk.
authors.forename: Miles D
authors.initials: MD
authors.lastname: Witham
authors.forename: Sheila
authors.initials: S
authors.lastname: Ireland
authors.forename: J Graeme
authors.initials: JG
authors.lastname: Houston
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gandy
authors.forename: Shelley
authors.initials: S
authors.lastname: Waugh
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Macdonald
authors.forename: Isla S
authors.initials: IS
authors.lastname: Mackenzie
authors.forename: Allan D
authors.initials: AD
authors.lastname: Struthers
mesh_terms: D000284:Administration, Oral; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: blood pressure; hypertension resistant to conventional therapy; vitamin D