Study of Vitamin D and Uric Acid Lowering on Kidney and Blood Vessel Function (MODERATE)

May 31, 2017 updated by: John P. Forman, Brigham and Women's Hospital

Modifiable Effectors of Renin System Activation: Treatment Evaluation (MODERATE)

The investigators hypothesize that, among non-hypertensive overweight and obese individuals, treatment of vitamin D deficiency and lowering uric acid concentrations (by either xanthine oxidase inhibition or increased renal excretion) will attenuate renin angiotensin system (RAS) activation, improve endothelial function, and lower blood pressure.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

We have demonstrated that lower levels of 25-hydroxyvitamin D (25[OH]D) and higher concentrations of uric acid are both potentially modifiable factors that are independently associated with an increased risk of developing hypertension (high blood pressure) in humans. Other investigators have shown that vitamin D supplementation, or lowering uric acid with allopurinol, may reduce blood pressure. Animal experiments suggest that activation of both the systemic and local kidney-specific renin angiotensin systems (RAS) may be the principal mechanism linking 25(OH)D and uric acid with hypertension. In human parallels to these animal studies, we have shown in cross-sectional analyses that non-hypertensive individuals with lower 25(OH)D and higher uric acid levels have increased activation of their systemic and kidney-specific RAS, independent of other factors. However, whether vitamin D supplementation or uric acid lowering attenuates RAS activation has never been demonstrated in humans. Both lower 25(OH)D and higher uric acid concentrations are also associated with endothelial dysfunction in humans, and endothelial function may modulate the RAS and provide an alternate mechanism for the development of hypertension. It remains unclear, however, whether an intervention to increase 25(OH)D or decrease uric acid levels among non-hypertensive adults improves endothelial function; furthermore, it is unknown whether treatment of these individuals would lower blood pressure. Determining whether treatment of 25(OH)D and uric acid concentrations, per se, can attenuate RAS activation, improve endothelial function, and lower blood pressure among nonhypertensive individuals is critically important, with implications stretching beyond hypertension prevention, since RAS activation, endothelial dysfunction, and blood pressure are also implicated in the pathology of cardiovascular and chronic kidney disease. Individuals who are overweight and obese (two-thirds of US adults) represent an important population who are known to have lower 25(OH)D levels, higher uric acid concentrations, activation of the RAS, endothelial dysfunction, and an increased risk of hypertension, cardiovascular disease, and chronic kidney disease. Interestingly, our preliminary data demonstrate that among overweight and obese individuals with normal 25(OH)D or low uric acid levels, adiposity is no longer associated with activation of the RAS, suggesting that low 25(OH)D and high uric acid concentrations might be mediators of the adverse consequences of overweight and obesity.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
242

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham and Women's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 25(OH)D < 20 ng/mL OR Uric acid ≥ 5 mg/dL
  • Age ≥ 18, ≤ 75 years
  • Body Mass Index (BMI) ≥ 25 kg/m^2

Exclusion Criteria:

  • Hypertension, or on BP-lowering medicine
  • Diabetes
  • Coronary Heart Disease
  • estimated glomerular filtration rate (EGFR) <60 mL/min
  • Kidney stones
  • Active cancer (except non-melanoma skin cancer)
  • Pregnant
  • Taking vitamin D supplements and unwilling to stop
  • Osteoporosis
  • Hypo- or hypercalcemia
  • Hypo- or hyperphosphatemia
  • Known allergy to angiotensin-converting enzyme (ACE)-inhibitors
  • Taking medication for hyperuricemia
  • Gout, anemia, cirrhosis, active/chronic hepatitis, abnormal aspartate aminotransferase (AST), alanine aminotransferase (ALT) or total bilirubin levels, or anemia
  • Known allergy to either allopurinol or probenecid
  • Current use of didanosine, azothioprine, methotrexate, ketoprofen, ketorolac, mycophenolate, or ACE-inhibitors

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Vitamin D
Vitamin D ergocalciferol 50,000 unit soft gel capsule once per week for 8 weeks.
Drug: Vitamin D ergocalciferol
50,000 unit soft gel capsule once per week for 8 weeks
Other Names:
  • Vitamin D
Experimental: Probenecid
Probenecid 500 mg tablet once per day for 4 weeks, then either 500 mg tablet once per day for 4 weeks or 1000 mg once per day for 4 weeks (8 weeks total).
Drug: Probenecid
500 mg tablet once per day for 4 weeks, then either 500 mg tablet once per day for 4 weeks or 1000 mg once per day for 4 weeks (8 weeks total)
Experimental: Allopurinol
Allopurinol 300 mg tablet once per day for 4 weeks then either 300 mg once per day or 600 mg once per day for 4 weeks (8 weeks total).
Drug: Allopurinol
300 mg tablet once per day for 4 weeks then either 300 mg once per day or 600 mg once per day for 4 weeks (8 weeks total)
Placebo Comparator: Placebo- Vitamin D
Placebo soft gel once per week for 8 weeks.
Drug: Placebo
Placebo soft gel once per week for 8 weeks
Drug: Placebo
Placebo tablet once per day for 4 weeks then twice per day for 4 weeks (eight weeks total)
Placebo Comparator: Placebo- Uric Acid
Placebo tablet once per day for 4 weeks then twice per day for 4 weeks (eight weeks total).
Drug: Placebo
Placebo soft gel once per week for 8 weeks
Drug: Placebo
Placebo tablet once per day for 4 weeks then twice per day for 4 weeks (eight weeks total)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Renal Plasma Flow (RPF) in Response to Captopril in High Sodium Balance [Vitamin D]
Time Frame: Week 8 (pre and post captopril)
Change in RPF in response to captopril is a measure of the vasodilator effect from inhibiting angiotensin II (AngII)- mediated vascular tone and therefore the degree of kidney specific Renin Angiotensin System (RAS) activity. Participants consumed a high sodium diet 3 days prior to the test. Following an 8 hour fast, participants remained in a supine (lying down) position and had an intravenous (IV) catheter inserted in each arm, one for infusion and one for blood collection. An 8 milligrams (mg)/kilogram(kg) loading dose of para-aminohippuric acid (PAH) was given, immediately followed by a continuous PAH infusion at 12 mg/minute. After 60 minutes a single dose of 25 mg of captopril was administered. Three pre-captopril measurements and three post-captopril measurements of RPF were made. RPF was normalized to body surface area of 1.73 meters squared (m^2). The change in RPF was calculated as post-captopril RPF- pre-captopril RPF.
Week 8 (pre and post captopril)
Plasma Renin Activity (PRA) [Vitamin D]
Time Frame: Week 8
PRA is a measure of systemic renin angiotensin system (RAS) activation. Blood was collected and plasma PRA was analyzed using a competitive binding radioimmunoassay (RIA) laboratory test.
Week 8
Angiotensin II (ATII) Concentration [Vitamin D]
Time Frame: Week 8
ATII concentration is a measure of systemic renin angiotensin system (RAS) activation. Blood was collected and plasma ATII was analyzed using a double-antibody radioimmunoassay (RIA) laboratory test.
Week 8
Change in Renal Plasma Flow (RPF) Response to Captopril in High Sodium Balance [Uric Acid]
Time Frame: Week 8 (pre and post captopril)
RPF in response to captopril iis a measure of the vasodilator effect from inhibiting angiotensin II (AngII)- mediated vascular tone and therefore the degree of kidney specific Renin Angiotensin System (RAS) activity. Participants consumed a high sodium diet 3 days prior to the test. Following an 8 hour fast, participants remained in a supine (lying down) position and had an intravenous (IV) catheter inserted in each arm, one for infusion and one for blood collection. An 8 milligrams (mg)/kilogram(kg) loading dose of para-aminohippuric acid (PAH) was given, immediately followed by a continuous PAH infusion at 12 mg/minute. After 60 minutes a single dose of 25 mg of captopril was administered. Three pre-captopril measurements and three post-captopril measurements of RPF were made. RPF was normalized to body surface area of 1.73 meters squared (m^2). The change in RPF was calculated as post-captopril RPF- pre-captopril RPF.
Week 8 (pre and post captopril)
Plasma Renin Activity (PRA) [Uric Acid]
Time Frame: Week 8
PRA is a measure of systemic renin angiotensin system (RAS) activation. Blood was collected and plasma PRA was analyzed using a competitive binding radioimmunoassay (RIA) laboratory test.
Week 8
Angiotensin II (ATII) Concentration [Uric Acid]
Time Frame: Week 8
ATII concentration is a measure of systemic renin angiotensin system (RAS) activation. Blood was collected and plasma ATII was analyzed using a double-antibody radioimmunoassay (RIA) laboratory test.
Week 8

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Endothelium-Dependent Vasodilation (EDV)
Time Frame: Baseline and Week 8 (pre and post ischaemic stimulus)
Endothelial function was assessed by EDV using brachial artery ultrasonography. Measurements of brachial artery diameter were made under basal conditions and reactive hyperemia following ischaemic stimulus. A blood pressure cuff on the forearm was pumped up for 5 minutes then released. Images were taken at baseline and after reactive hyperemia (increased blood flow). The maximum diameter was determined by the investigator. Change in EDV was expressed as a percent of brachial luminal diameter calculated as post-ischaemic brachial artery diameter - pre-ischaemic brachial artery diameter/pre-ischaemic brachial artery diameter * 100.
Baseline and Week 8 (pre and post ischaemic stimulus)
Mean 24-Hour Ambulatory Blood Pressure (ABP)
Time Frame: Baseline and Week 8
A 24-hour mean ambulatory blood pressure was monitored using a 24 hour ABP device. The ABP device is a small box that is worn on the belt or pant/skirt line with a line that connect under the clothing to the cuff on the upper arm. Blood Pressure was recorded every 30 minutes during the day and every 60 minutes during the night for 24 hours.
Baseline and Week 8
Mean 24-Hour Ambulatory Blood Pressure (ABP) Nocturnal Dipping
Time Frame: Baseline and Week 8
A 24-hour mean ambulatory blood pressure was monitored using a 24 hour ABP device. The ABP device is a small box that is worn on the belt or pant/skirt line with a line that connect under the clothing to the cuff on the upper arm. Blood Pressure was recorded every 30 minutes during the day and every 60 minutes during the night for 24 hours. Nocturnal dipping is the percent change lower between the daytime and nighttime values.
Baseline and Week 8

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Brigham and Women's Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Heart, Lung, and Blood Institute (NHLBI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: John P Forman, MD, MSc, Brigham and Women's Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2011

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2015

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2015

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 21, 2011

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 21, 2011

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 22, 2011

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 29, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 31, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2010-P-002049
  • 1R01HL105440 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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