Styrian Vitamin D Hypertension Trial

Study Overview
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Brief Summary
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In this randomized, double-blind, placebo-controlled trial we plan to enrol 200 vitamin D deficient hypertensive patients. Our main objective is to evaluate whether vitamin D3 supplementation with 2,800 IU daily for 8 weeks has an effect on 24-hour systolic ambulatory blood pressure (ABP) compared to placebo. In addition, we also aim to evaluate whether vitamin D3 supplementation alters 24-hour diastolic ABP, pulse wave velocity, N-terminal-pro-brain natriuretic peptide (NT-pro-BNP), corrected QT interval (Bazett formula), renin, aldosterone, 24-hour urinary albumin excretion, HOMA-IR (HOmeostatic Model Assessment: Insulin Resistance), triglycerides and HDL-cholesterol.

Official Title
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Styrian Vitamin D Hypertension Trial: A Randomized, Double-blind, Placebo Controlled Trial to Evaluate the Effects of Vitamin D Supplementation on Systolic Ambulatory Blood Pressure in Vitamin D Deficient Hypertensive Patients

Conditions
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Arterial Hypertension, Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: Vitamin D3
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 25-hydroxyvitamin D levels below 30 ng/ml (75 nmol/L) Arterial hypertension defined according to recent guidelines as an average office blood pressure on at least two occasions of systolic ≥ 140 and/or diastolic ≥ 90 mmHg or a mean 24-hour ABP of systolic ≥ 125 and/or diastolic ≥ 80, or a home blood pressure of systolic ≥ 130 and/or diastolic ≥ 85 or ongoing antihypertensive treatment which was initiated due to arterial hypertension Age of ≥ 18 years Written informed consent. Exclusion Criteria: Hypercalcemia defined a serum calcium >2.65 mmol/L Pregnancy or lactating women Drug intake as part of another clinical study Acute coronary syndrome or cerebrovascular events in the previous 2 weeks Glomerular filtration rate (GFR) according to the MDRD formula < 15 ml/min/1.73m² Systolic 24-hour ABP > 160 mm Hg or < 120 mm Hg Diastolic 24-hour ABP > 100 mm Hg Change of antihypertensive treatment (drugs and/or lifestyle) in the previous 4 weeks or planned changes of antihypertensive treatment during the study Any disease with an estimated life expectancy below 1 year Any clinically significant acute disease requiring drug treatment Chemotherapy or radiation therapy during the study Regular intake of more than 880 International Units (IU) vitamin D per day in the last four weeks before study entry or during the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Vitamin D3<br>The treatment group receives 2,800 IU vitamin D3 per day as oily drops (Oleovit D3; producer: Fresenius Kabi Austria, A-8055 Graz) for 8 weeks | Dietary Supplement: Vitamin D3<br>* The treatment group receives 2,800 IU vitamin D3 per day as oily drops (Oleovit D3, producer: Fresenius Kabi Austria, A-8055 Graz) for 8 weeks<br>|
| Placebo Comparator: Placebo<br>Oily drops as placebo | Dietary Supplement: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-hour systolic ambulatory blood pressure |  | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-hour diastolic ambulatory blood pressure |  | 8 weeks | 
| N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) |  | 8 weeks | 
| corrected QT interval (Bazett formula) |  | 8 weeks | 
| Renin | Plasma renin concentration | 8 weeks | 
| Aldosterone | Plasma aldosterone concentration | 8 weeks | 
| 24-hour urinary albumin excretion |  | 8 weeks | 
| HOMA-IR | HOMA-IR (HOmeostatic Model Assessment: Insulin Resistance) | 8 weeks | 
| Triglycerides |  | 8 weeks | 
| HDL-cholesterol |  | 8 weeks | 
| Pulse wave velocity |  | 8 weeks |