The Study of the Effects of Vitamin A on Immune System in Patients With Atherosclerosis

NCT ID: NCT00963222

Last Updated: 2012-06-05

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: PHASE4
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-09-30
• Study Completion Date: 2013-03-31

Brief Summary

The aim of this study is the comparison between the effects of supplementation with 25000 IU preformed vitamin A (retinyl palmitate) or placebo for 3 months on immune system and Th1/Th2 balance in patients with and without atherosclerosis (documented with angiography).

Detailed Description

Atherosclerosis, the leading cause of death and disability in the world, is considered an inflammatory disease with a complex etiology. The immune system has a prominent role in the formation, development and destabilization of atherosclerotic plaques. A whole range of identified cytokines have been shown to play a part in atherogenesis, some with proatherogenic properties while others having antiatherogenic properties. With increasing evidence for the significant role of inflammation and the cytokines involved together with the Th1/Th2 imbalance in atherosclerosis and its progression to Coronary artery diseases (CADs), the control of cytokine production may become potential therapeutic targets and modulation of the Th1/Th2 balance may provide a new pharmacological tool to treat this disease. Vitamin A (VA) or VA-like analogs known as retinoids, are potent hormonal modifiers of type 1 or type 2 responses but a definitive description of their mechanism(s) of action is lacking. high level dietary vitamin A enhances Th2 cytokine production and IgA responses, and is likely to decrease Th1 cytokine production. Retinoic acid inhibits IL 12 production in activated macrophages, and RA pretreatment of macrophages reduces IFNγ production and increases IL4 production in antigen primed CD4 T cells. Supplemental treatment with vitamin A or retinoic acid (RA) decreases IFNγ and increases IL5, IL10, and IL4 production. Thus, vitamin A deficiency biases the immune response in a Th1 direction, whereas high level dietary vitamin A may bias the response in a Th2 direction.

Conditions

Atherosclerosis

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: QUADRUPLE

Study Groups

with atherosclerosis/ vitamin A

patients with angiographically confirmed CAD (defined as luminal stenosis ≥50% in at least one major coronary artery branch)who receive 25000 IU/day vitamin A

Group Type: ACTIVE_COMPARATOR

vitamin A

Intervention Type: DRUG

1 cap vitamin A 25000 IU/day for 3 month

with atherosclerosis/ placebo

patients with angiographically confirmed CAD (defined as luminal stenosis ≥50% in at least one major coronary artery branch)who receive placebo

Group Type: PLACEBO_COMPARATOR

placebo

Intervention Type: DRUG

1 cap placebo/day for 3 month

without atherosclerosis/ vitamin A

patients in whom significant (e.g. stenosis ≥ 50%) CAD is ruled out by coronary angiography, who receive 2500 Iu/day vitamin A

Group Type: ACTIVE_COMPARATOR

vitamin A

Intervention Type: DRUG

1 cap vitamin A 25000 IU/day for 3 month

without athrosclerosis/ placebo

patients in whom significant (e.g. stenosis ≥ 50%) CAD is ruled out by coronary angiography, who receive placebo

Group Type: PLACEBO_COMPARATOR

placebo

Intervention Type: DRUG

1 cap placebo/day for 3 month

Interventions

vitamin A

1 cap vitamin A 25000 IU/day for 3 month

Intervention Type: DRUG

placebo

1 cap placebo/day for 3 month

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• The criteria for enrollment of the patients and control subjects is consecutive patients of both sexes referred to the Division of Cardiology of the one of the Hospitals of Tehran University of Medical Sciences for coronary angiography for investigation of chest pain and/or suspected CAD.

Exclusion Criteria

• Patients who have diseases which affect on Th1/Th2 balance such as asthma, active viral infections, and autoimmune diseases, OR
• Patients who have allergy to vitamin A compounds, OR
• Patients who have used vitamin supplements in last 3 months.

• Minimum Eligible Age: 35 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Tehran University of Medical Sciences

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Ali Akbar saboor Yaraghi, PhD

Role: STUDY_CHAIR

Tehran University of Medical Sciences

Maryam Mahmoudi, MD, PhD student

Role: PRINCIPAL_INVESTIGATOR

Tehran University of Medical Siences

Fereidon Siassi, PhD

Role: STUDY_CHAIR

Tehran University of Medical Sciences

Locations

Tehran University of Medical Sciences, School of Public Health

Tehran, Tehran Province, Iran

Countries

Iran

Other Identifiers

86-04-27-6617

Identifier Type: -

Identifier Source: org_study_id