Vitamins C and Vitamin E and Cardiovascular Risk

This study has been completed.
Sponsor:
Collaborator:
American Diabetes Association
Information provided by:
University of New Mexico
ClinicalTrials.gov Identifier:
NCT00362518
First received: August 9, 2006
Last updated: September 2, 2008
Last verified: September 2008
  Purpose

The proposed study will examine the hypothesis that vitamin C and vitamin E given to type 2 diabetic individuals will provide effective anti-inflammatory, anti-thrombotic, and anti-oxidative atherosclerotic protection when administered at the optimal dose as determined by surrogate markers of inflammation, hypercoagulability, and oxidation.


Condition Intervention Phase
Diabetes
Dietary Supplement: Study Arm A
Dietary Supplement: Study Arm B
Dietary Supplement: Study Arm C
Dietary Supplement: Study Arm D
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacodynamics Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Vitamin C and Vitamin E Therapy in Type 2 Diabetes and Cardiovascular Risk

Resource links provided by NLM:


Further study details as provided by University of New Mexico:

Primary Outcome Measures:
  • The goal is to determine the effects of the vitamin C and vitamin E on surrogate markers of atherosclerosis following an atherogenic meal in type 2 diabetes [ Time Frame: 2 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • To determine changes in surrogate markers of atherosclerosis in type 2 diabetes [ Time Frame: 2 months ] [ Designated as safety issue: No ]

Enrollment: 12
Study Start Date: July 2004
Study Completion Date: March 2008
Primary Completion Date: June 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: 1
Study Arm A - Control: no vitamins (placebo only).
Dietary Supplement: Study Arm A
Control: no vitamins (placebo only). This study will provide baseline metabolic and surrogate marker changes that are caused by the high fat meal. Study arms B, C, and D will be statistically compared to this study.
Other Name: Study Arm A
Active Comparator: 2
Study Arm B - Low Dose: Vitamin C 250 mg, Vitamin E 200 IU
Dietary Supplement: Study Arm B
This study arm will provide information on the response of atherogenic surrogate markers to a high fat supper when a low dosage form of vitamin C is administered (250 mg) and Vitamin E (200 IU).
Other Name: Study Arm B
Active Comparator: 3
Study Arm C - Medium Dose: Vitamin C 500 mg, Vitamin E 400 IU
Dietary Supplement: Study Arm C
This study arm will provide information on the response of atherogenic surrogate markers to a high fat supper when a medium dosage form of vitamin C administered (500 mg)and Vitamin E (400 IU).
Other Name: Study Arm C
Active Comparator: 4
Study Arm D - High Dose: Vitamin C 1000 mg, Vitamin E 800 IU.
Dietary Supplement: Study Arm D
This study arm will provide information on the response of atherogenic surrogate markers to a high fat supper when a high dosage form of vitamin C is administered (1000 mg) and Vitamin E (800 IU).
Other Name: Study Arm D

Detailed Description:

This American Diabetes Association research project is to determine why there are discrepant results between individual studies of Vitamin E and C in both animals and humans compared with the results obtained in large randomized human trials using Vitamin E.

Subjects: The study will enroll subjects (both men and women) with type 2 diabetes of at least six months duration. An outpatient screening test will utilize the following: a complete history and physical examination, an EKG, a urine hcG (only for women of childbearing age), and the following blood tests: CBC, Chem-20, lipid profile, hemoglobin A1C, and C-peptide stimulation test. Subjects will be excluded if they have known vascular disease, uncontrolled hypertension (>140/90 mmHg) or marked hyperlipidemia (serum low density lipoprotein > 4.1 mmol/L or serum triglycerides > 7.8 mmol/L). Eligible patients must have normal electrocardiogram tracings and normal screening test results (described above). Other important exclusion criteria are cigarette smoking, volunteers taking Coumadin, and recent use of antioxidant supplements or aspirin. All patients will provide written informed consent before enrollment as approved by the University of New Mexico Human Research Review Committee.

Surrogate Markers: Based on our preliminary data and the published medical literature, it is extremely likely that vitamins C and E will modify all three contributors to atherosclerosis: Oxidative stress, Hypercoagulability, and Inflammation. Therefore, as shown in the table above, we have included standard surrogate markers for all three of these contributors.

Specific Aim: Determine the optimal oral dose of vitamin C and vitamin E relative to the consumption of an atherogenic high fat supper in type 2 diabetic individuals. These data are necessary in order to design prospective clinical trials in which vitamins are given to prevent or delay atherosclerotic events. One reason that published clinical trials demonstrate conflicting results may be the different dosages of vitamins that have been utilized. In the following study, we will utilize our high fat (simulated Big Mac) meal to assess the beneficial effects of these vitamins on surrogate markers of atherosclerosis. Three dosages of vitamins will be utilized in order to determine the optimal dosage.

The three dosages to be tested are 1) low dose - vitamin C 250mg, vitamin E 200 IU 2) medium dose - vitamin C 500 mg, vitamin E 400 IU and 3) high dose - vitamin C 1000mg, vitamin E 800 IU. The results will be compared to a control meal study in which only placebo (hence, no vitamins) is administered. The vitamins will be administered before breakfast on each study day.

  Eligibility

Ages Eligible for Study:   18 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • The study will enroll subjects, both men and women with type 2 diabetes of at least six months duration. The age of enrolled subjects will range from 21-60 years old. An HbA1c blood test must show that the person's diabetes is under control. Eligible subjects must have normal electrocardiogram tracings and normal hematological, electrolyte and liver laboratory results at screening. Females of childbearing age must agree to use an effective form of birth control throughout the study period.

Exclusion Criteria:

  • Subjects will be excluded if they have known vascular disease, uncontrolled hypertension (>140/90 mmHg), marked hyperlipidemia (serum low density lipoprotein > 4.1 mmol/L or serum triglycerides > 7.8 mmol/L), and a body mass index greater than 40 kg/m2 (range 27-40). Other important exclusion criteria are cigarette smoking, volunteers taking Coumadin, and recent use of antioxidant supplements or aspirin. Females who are pregnant or breastfeeding will be excluded. People cannot participate in this study if they are taking medications (other than antidiabetic medications) which may affect blood sugar.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00362518

Locations
United States, New Mexico
University of New Mexico Health Sciences Center
Albuquerque, New Mexico, United States, 87131
Sponsors and Collaborators
University of New Mexico
American Diabetes Association
Investigators
Principal Investigator: David S Schade, M.D. University of New Mexico School of Medicine
  More Information

No publications provided by University of New Mexico

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: David S. Schade, University of New Mexico
ClinicalTrials.gov Identifier: NCT00362518     History of Changes
Other Study ID Numbers: 04-319, 7-04-CR-41
Study First Received: August 9, 2006
Last Updated: September 2, 2008
Health Authority: United States: Institutional Review Board

Keywords provided by University of New Mexico:
atherosclerosis
vitamin C
vitamin E

Additional relevant MeSH terms:
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Ascorbic Acid
Vitamin E
Alpha-Tocopherol
Tocopherols
Tocotrienols
Vitamins
Antioxidants
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Protective Agents
Physiological Effects of Drugs
Micronutrients
Growth Substances

ClinicalTrials.gov processed this record on August 28, 2014