Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
PHASE3
512 participants
INTERVENTIONAL
2010-01-31
2012-07-31
Brief Summary
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Detailed Description
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Adipose tissue is a source of inflammatory cytokines, and obesity is now viewed as a chronic, low-grade inflammatory state. Inflammation itself is a contributor to the chronic diseases associated with obesity. C-reactive protein (CRP) is a key marker of inflammation, and as a downstream marker it provides functional integration of upstream cytokine activation associated with inflammation. We have previously shown that vitamin C, but not vitamin E, reduces CRP in active and passive smokers and in nonsmokers. The reduction is seen primarily in persons with CRP ≥1.0 mg/L, the CDC threshold for elevated cardiovascular disease risk. We also found that 75% of obese nonsmokers had CRP ≥1.0 mg/L.
The important observation of reduction in elevated CRP by vitamin C now needs to be confirmed in a rigorous study with adequate sample size, to permit justifiable conclusions about the potential usefulness of this agent in reducing inflammation in the obese. We will conduct a placebo-controlled, randomized trial in 552 healthy obese individuals with moderate CRP elevations (CRP ≥1.0 mg/L). Participants will be randomized to either 1000 mg/day vitamin C or placebo for a period of 2 months. We will also characterize the pathways through which this effect takes place by measuring cytokines and oxidative stress.
This project is important because if our previous finding is confirmed in this population, it could offer a low-cost alternative to use of statins to reduce inflammation in persons without other risk factors.
Conditions
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Study Design
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RANDOMIZED
PARALLEL
PREVENTION
QUADRUPLE
Study Groups
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Placebo
Two tablets, daily, for 8 weeks
Placebo tablet
Placebo tablet (two 500-mg tablets), 8 weeks
Vitamin C
Two tablets, daily, for 8 weeks
Vitamin C (ascorbic acid)
1000 mg/day (two 500-mg tablets), 8 weeks
Interventions
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Vitamin C (ascorbic acid)
1000 mg/day (two 500-mg tablets), 8 weeks
Placebo tablet
Placebo tablet (two 500-mg tablets), 8 weeks
Eligibility Criteria
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Inclusion Criteria
* hsCRP ≥ 1 mg/L
* Age 18+
* Member of Kaiser Permanente Health Plan of Northern California
Exclusion Criteria
* Unwilling to discontinue vitamin supplements for study duration
* Unwilling/unable to use acetaminophen in place of OTC anti-inflammatory medications
* Use of certain medications
* History of certain medical conditions
18 Years
ALL
Yes
Sponsors
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Kaiser Permanente
OTHER
University of California, Berkeley
OTHER
Responsible Party
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Gladys Block
Professor Emerita
Principal Investigators
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Gladys Block, PhD
Role: PRINCIPAL_INVESTIGATOR
University of California, Berkeley
Locations
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Kaiser Permanente of Northern California, Division of Research
Oakland, California, United States
Countries
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References
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Block G, Jensen CD, Dalvi TB, Norkus EP, Hudes M, Crawford PB, Holland N, Fung EB, Schumacher L, Harmatz P. Vitamin C treatment reduces elevated C-reactive protein. Free Radic Biol Med. 2009 Jan 1;46(1):70-7. doi: 10.1016/j.freeradbiomed.2008.09.030. Epub 2008 Oct 10.
Block G, Jensen C, Dietrich M, Norkus EP, Hudes M, Packer L. Plasma C-reactive protein concentrations in active and passive smokers: influence of antioxidant supplementation. J Am Coll Nutr. 2004 Apr;23(2):141-7. doi: 10.1080/07315724.2004.10719354.
Other Identifiers
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DK062378-05
Identifier Type: -
Identifier Source: org_study_id