Vitamin D Deficiency Augments Renin-Angiotensin System Activity in Obesity
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Brigham and Women's Hospital
- Enrollment
- 26
- Locations
- 2
- Primary Endpoint
- The Change in the Mean Arterial Blood Pressure in Response to an Infusion of Angiotensin II
Study Overview
Brief Summary
Hypothesis: Vitamin D supplementation lower renin-angiotensin system activity in obesity.
Specific Aim: To investigate whether Vitamin D supplementation in obesity improves the vascular sensitivity to angiotensin II.
Detailed Description
Vitamin D deficiency and obesity are international epidemics that have both been associated with increased activity of the renin-angiotensin system (RAS). Because increased RAS activity is associated with cardiovascular disease, interventions to lower RAS will have favorable public health impacts.
This study aims to evaluate whether the supplementation of Vitamin D in obese subjects will lower local tissue RAS activity. RAS activity will be evaluated by cross-sectional measurement of RAS components and by quantifying the vascular response to an infusion of angiotensin II. Subjects will be studied while Vitamin D deficient, and will return for repeat study following Vitamin D supplementation, for comparison.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Other
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 64 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •age < 65,
- •Cr < 1.6,
- •25-hydroxyvitamin D < 25 ng/mL,
- •BMI > 30 kg/m2,
- •stage I hypertension.
Exclusion Criteria
- •diabetes,
- •coronary heart disease,
- •heart failure,
- •renal failure,
- •liver failure,
- •hyperparathyroidism,
- •granulomatous disease.
Outcomes
Primary Outcomes
The Change in the Mean Arterial Blood Pressure in Response to an Infusion of Angiotensin II
Time Frame: baseline and 1 month following vitamin D3 therapy
Secondary Outcomes
- The Change in Renal Blood Flow in Response to an Infusion of Angiotensin II(baseline and 1 month following vitamin D3 therapy)
Investigators
Jonathan S. Williams, MD, MMSc
Assistant Professor of Medicine
Brigham and Women's Hospital