Study of the Effects of Vitamin C on Patients With Type 2 Diabetes
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT00001870|
Recruitment Status : Completed
First Posted : November 4, 1999
Last Update Posted : March 4, 2008
Diabetes is a disease characterized by decreased sensitivity to the action on insulin to promote sugar (glucose) use and blood vessel relaxation (vasodilation) in muscle. Insulin's ability to cause blood vessel relaxation is controlled, in part, by nitric oxide (NO).
Nitric oxide is a substance produced by the cells lining blood vessel walls (endothelium). Increased blood flow to the muscle accounts for increased sugar (glucose) to areas of the body. Therefore, if the cells of blood vessel walls (endothelium) are not functioning properly it may contribute to insulin resistance.
Injections of Vitamin C directly into the arteries have been shown to improve blood vessel reaction to nitric oxide in diabetic patients. Researchers believe this may be due to Vitamin C's ability to increase the levels of nitric oxide in blood vessels.
The goal of this study is to determine the effects of vitamin C on both insulin sensitivity and endothelium function of patients with type 2 diabetes. An additional goal of the study is to determine the effects of vitamin C on patients with vitamin C deficiency.
Patients participating in this study will undergo a series of testes to determine insulin sensitivity and blood vessel reactivity. Patients will be divided into two groups. One group will receive doses of oral vitamin C. The other group will receive doses of a placebo (inactive pill not containing vitamin C). Patients will receive the medications for four weeks and then be tested again for insulin sensitivity and blood vessel reactivity.
Researchers believe that doses of vitamin C in diabetics or patients with vitamin C deficiency will improve insulin sensitivity and function of endothelium. Results gathered form this study may provide information about vitamin C levels in diabetics and may lead to the development of new therapies to treat insulin resistance and endothelium dysfunction.
|Condition or disease||Intervention/treatment||Phase|
|Diabetes Mellitus, Non-Insulin Dependent Non-Insulin Dependent||Drug: Acetylcholine||Phase 2|
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||150 participants|
|Official Title:||An Exploratory Study of the Effects of Oral Vitamin C Administration on Insulin Sensitivity and Vascular Reactivity in Subjects With Type 2 Diabetes|
|Study Start Date :||January 1999|
|Estimated Study Completion Date :||December 2004|
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00001870
|United States, Maryland|
|National Center for Complementary and Alternative Medicine (NCCAM)|
|Bethesda, Maryland, United States, 20892|