Effect of Vitamin D Replacement During Winter Months in Patients With Hypertension

Study Overview
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Brief Summary
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High blood pressure is related to increased risk of cardiovascular disease and death, and accounts for approximately 8 mill deaths worldwide each year. Blood pressure exhibits a seasonal variation with a tendency to increase during winter months. Vitamin D deficiency is more common during months where UVB radiation from the sun is absent, and vitamin D has been associated with high blood pressure. This study will evaluate the effect of vitamin D replacement during winter months on blood pressure and vasoactive hormones in patients with high blood pressure.

Official Title
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Effect of Cholecalciferol on 24-hr ABPM and Vasoactive Hormones in Patients With Hypertension.

Conditions
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Hypertension, Vitamin D Deficiency

Intervention / Treatment
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* Drug: Cholecalciferol
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Well-regulated arterial hypertension Office blood pressure > 120/70 mmHg Exclusion Criteria: Pregnancy or nursing Cancer Alcohol abuse Continuous glucocorticoid or NSAID treatment 24-hour blood pressure > 150/95 mmHg Hypercalcemia

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: Cholecalciferol<br> | Drug: Cholecalciferol<br>* 3 tablets of 1000 IU daily for 20 weeks<br>|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* 3 placebo tablets daily for 20 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-hour systolic blood pressure |  | 20 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma renin concentration |  | 20 weeks | 
| Plasma concentration of angiotensin II |  | 20 weeks | 
| Plasma concentration of aldosterone |  | 20 weeks | 
| Plasma concentration of c-reactive protein |  | 20 weeks | 
| Urine albumin creatinine ratio |  | 20 weeks | 
| Urine calcium creatinine ratio |  | 20 weeks | 
| Plasma concentration of 25-hydroxycholecalciferol |  | 5 weeks | 
| Serum concentration of FGF-23 |  | 20 weeks | 
| Augmentation index and central blood pressure |  | 20 weeks | 
| Pulse wave velocity |  | 20 weeks | 
| Heart rate variability |  | 20 weeks | 
| Plasma concentration of ionized calcium |  | 5 weeks | 
| Plasma concentration of phosphate |  | 5 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypertension, blood pressure, vitamin d, winter, cholecalciferol, arterial stiffness, renin, angiotensin, aldosterone, calcium