Vitamin D Therapy to Reduce Blood Pressure and Left Ventricular Hypertrophy in Resistant Hypertension Randomized, Controlled Trial Original Article

R esistant hypertension, defined as an office systolic blood pressure of >140 mm Hg or diastolic blood pressure of >90 mm Hg, despite maximally tolerated treatment with ≥3 antihypertensive agents, affects 10% to 30% of patients with hypertension. 1 Resistance to treatment is associated with a high incidence of cardiovascular events. 2 Resistant hypertension is also associated with a high incidence of left ventricular (LV) hypertrophy, 3 itself a risk factor for cardiovascular events, arrhythmias, and death. Low vitamin D levels are associated with higher blood pressure 7 and a higher rate of both incident hypertension 8 and cardiovascular disease 9,10 in observational studies. Previous intervention trials 14,15 Therefore, we conducted a randomized controlled trial to test the effect of intermittent high-dose vitamin D on 24-hour ambulatory blood pressure and LV mass in patients with resistant hypertension. 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 4