Niacin to Improve Blood Flow in People With Sickle Cell Disease
Public ClinicalTrials.gov record NCT00508989. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Niacin Therapy to Improve Endothelial Function in Sickle Cell Disease
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This study will determine whether niacin can improve blood flow in people with sickle cell disease, in which abnormal red blood cells interfere with blood flow to cause the disease symptoms. Niacin, a drug that has been used to increase HDL (good cholesterol) levels, improves blood flow in people without sickle cell disease. This study will see if it can do the same in people with the disease. Patients with sickle cell disease between 18 and 65 years of age may be eligible for this study. Candidates are screened with a medical history, physical examination, blood tests, echocardiogram and 6-minute walk test of exercise capacity. Participants have the following baseline blood flow studies: * Flow-mediated dilation (FMD): An ultrasound picture of the artery in the forearm is obtained. A blood pressure cuff is then placed on the upper arm and inflated for 5 minutes. After the pressure cuff is released, the ultrasound is repeated. * Peripheral artery tonometry (PAT): A sensor is placed on the subject s finger. The sensor puts pressure on the finger and measures blood flow. * Standard forearm blood flow test: Small tubes are placed in the artery of the forearm at the inside of the elbow. Saline is infused into one tube. Pressure cuffs are applied to the wrist and upper arm. A strain gauge (rubber band device) is placed around the forearm. When the cuffs are inflated, blood flows into the arm, stretching the strain gauge, and the flow measurement is recorded. Blood samples are collected from the tube in the artery to measure blood counts, proteins and other chemicals. At various times, small doses of the following drugs are administered through the tube in the vein: * Sodium nitroprusside causes blood vessels to dilate and increases blood flow to the heart. * Acetylcholine causes blood vessels to dilate and slows heart rate. * LNMMA decreases blood flow by blocking the production of nitric oxide. Blood flow is measured after each dose of the different drugs. There are rest periods between injections of the different drugs. Pictures of the forearm are taken during the studies using an infrared camera and computer. -Drug Treatment. Participants are assigned to take three 4-week courses of niacin or placebo. They return to the Clinical Center at the following intervals from the time they start the test drug for followup: * Weeks 2, 6 and 10: Brief medical history, review of medication side effects and blood tests. * Weeks 4 and 8: Physical examination, brief medical history, review of medication side effects and blood tests, repeat FMD and PAT blood flow studies and 6-minute walk test. * Week 12: Same as weeks 4 and 8 plus standard blood flow studies and echocardiogram.
Study identification
- NCT ID
- NCT00508989
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 30 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 65 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jul 23, 2007
- Primary completion
- Dec 30, 2010
- Completion
- Dec 23, 2015
- Last update posted
- Sep 9, 2020
2007 – 2015
United States locations
- U.S. sites
- 2
- U.S. states
- 2
- U.S. cities
- 2
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Howard University Hospital | Washington D.C. | District of Columbia | 20060 | — |
| National Institutes of Health Clinical Center, 9000 Rockville Pike | Bethesda | Maryland | 20892 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00508989, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Sep 9, 2020 · Synced Sep 3, 2026
Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.
Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00508989 live on ClinicalTrials.gov.