Vitamin E and C to Slow Progression of Common Carotid Artery Plaque Build-Up

Antioxidants and Prevention of Early Atherosclerosis

This study will evaluate the effects of vitamin E supplementation in retarding the progression of common carotid artery intima-media thickening in African Americans.

Study Overview

Detailed Description

BACKGROUND:

Evidence from epidemiologic studies, and from one unpublished study, suggests that greater intake of antioxidant vitamins is associated with reduced risk of coronary heart disease and stroke. Findings from an animal model indicate that increased intake of antioxidant vitamins prevents progression of aortic fatty streaks induced by an atherogenic diet, but not from more advanced injury-induced lesions. These observations suggest the hypothesis that increased antioxidant vitamin intake may prevent further progression of early atherosclerosis, possibly by means of reduced susceptibility of low density lipoprotein to oxidative modification and consequent cytotoxic, chemotactic, chemostatic, and unregulated uptake effects.

A new, automated, low-cost, portable ultrasound system for determining intima-media thickness of the common carotid artery makes it feasible to test the primary prevention impact of antioxidant vitamins on early atherosclerosis. Results of two studies at the University of Southern California suggest that the low-density lipoprotein effects on common carotid artery intima-media thickness can be detected by automated methods within 12 to 24 months in small patient samples. Retardation of intima-media thickness progression was achieved in both studies without significant changes in average vessel diameter, which suggests effects on early atherosclerotic lesions.

DESIGN NARRATIVE:

Patients will be screened for carotid intima-media thickness at home or at schools in mobile vans equipped with portable ultrasound equipment. After 12 months, those patients above the age and sex-adjusted 66th percentile at Screen I will be re-screened (Screen II), and those showing the greatest progression in intima-media thickness will be invited to participate in a trial run-in to assess vitamin E compliance. Patients will be randomized to the following four groups: 1) vitamin E (573 mg/day); 2) vitamin C; 3) Vitamin E and C combined; and 4) placebo. Common carotid artery intima-media thickness will be observed by ultrasound at 12- and 24-month follow-ups. The primary outcome is 24-month rate of change in average common carotid artery intima-media thickness.

The study completion date listed in this record was obtained from the Query/View/Report (QVR) System.

Study Type

Interventional

Phase

  • Phase 2

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

Ages Eligible for Study

35 years to 59 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • African American

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: Prevention
  • Allocation: Randomized

What is the study measuring?

Primary Outcome Measures

Outcome Measure
rate of change in average common carotid artery intima-media thickness (measured over 24 months)

Collaborators and Investigators

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

Investigators

  • Principal Investigator: James H. Dwyer, III, University of Southern California

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

June 1, 1995

Study Completion (Actual)

May 1, 2000

Study Registration Dates

First Submitted

October 27, 1999

First Submitted That Met QC Criteria

October 27, 1999

First Posted (Estimate)

October 28, 1999

Study Record Updates

Last Update Posted (Estimate)

December 13, 2013

Last Update Submitted That Met QC Criteria

December 12, 2013

Last Verified

October 1, 2006

More Information

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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