Effects of Niacin Therapy on Lipoprotein Composition and Function
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases
Study type: Interventional
Phase: Phase 2

Summary: 
      Background:

      - Niacin is a vitamin in many foods, including meats, fish, fruits, and vegetables. It is
      often used as a dietary supplement that causes many improvements in the body. Researchers
      think it can affect heart health.

      Objective:

      - To better understand the good effects of niacin supplementation on cholesterol, fat
      metabolism, and vascular health.

      Eligibility:

      - Adults 18 years of age and older with fasting good cholesterol (HDL-C) below 60 mg/dL.

      Design:

        -  Participants will come to the clinic 4 times during the study.

        -  They will complete a 7-day food journal before visits 1 and 3.

        -  At visit 1, participants will be screened with questions about their diet and exercise,
           medical history, and any drugs and vitamins they take. Vital signs and body mass index
           will be measured.

        -  They will have a Cardio-Ankle Vascular Index (CAVI) test of the arteries. Blood pressure
           will be taken in the arms and legs and the heart will be monitored.

        -  Blood will be drawn. Participants will fast for 8 12 hours before this.

        -  Women will have a pregnancy test.

        -  Eligible participants will get a 2-week supply of niacin. They will take 2 tablets daily
           for one week, then 4 daily.

        -  Visit 2 will be 2 weeks after visit 1 and the niacin dose will be increased. Visit 3
           will be 16 weeks after visit 1, and participants will stop taking niacin. Visit 4 will
           be 4 6 weeks after stopping niacin.

        -  During study visits, participants will repeat visit 1 tests.
    

Detailed description: 
      This single center clinical pilot study will investigate the effects of niacin on blood
      lipids and lipoprotein composition in human subjects who are healthy. Niacin (vitamin B3 or
      nicotinic acid) is a common nutrient found in many foods and is currently sold over the
      counter as a nutritional supplement. Extended-release versions of niacin are available over
      the counter (e.g., Slo-Niacin) or by prescription (Niaspan) and help to alleviate symptoms of
      flushing associated with larger doses of the vitamin. Studies of the effects of niacin
      therapy on clinical lipid measures consistently indicate a shift toward a healthier
      lipoprotein profile with increased HDL-C and decreases in both triglyceride and LDL-C.
      Despite this favorable shift in lipid profile, cardiovascular outcome studies on patients
      receiving niacin alone or in combination with statin therapy have resulted in mixed results
      creating uncertainty of the value of niacin therapy. The proposed study will examine in
      detail the effects of niacin therapy on lipoprotein composition and function, while also
      tracking measures of vascular health.
    

Intervention name(s): Niacin Extended Release
Intervention type(s): Dietary Supplement
Intervention description(s): Subjects will receive a 2 week supply of the dietary supplement Rugby Extended Release Niacin (250 mg/tablet) Niacin and will be instructed to take 2 tablets per day (500 mg/day) for the first seven days and then increase to 4 tablets per day (1000 mg/day) during the following 7 days. Subjects will then be escalated to 2000 mg/day for 14 weeks.
Other intervention name(s): Niacin Extended Release (ER); Niacin
Intervention MeSH terms: Niacin; Niacinamide; Nicotinic Acids
Intervention model: Single Group Assignment
Intervention model description: This novel pilot study will be carried out at the NIH Clinical Center outpatient clinic 7 in healthy volunteers. We will screen up to 200 subjects, males and females, to obtain at least 32 completed studies. Participants will be recruited via flyer, and/or recruitment advertisement placed in the NIH Record, the NHLBI Recruitment website, the Clinical Center News and by email/listserv.
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Niacin; Cholesterol; High-Density Lipoprotein; Low-Density Lipoprotein; Lipoproteins