Obesity, Inflammation and Oxidative Stress

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. Identifier: NCT01028976
Recruitment Status : Completed
First Posted : December 9, 2009
Last Update Posted : December 2, 2015
Kaiser Permanente
Information provided by (Responsible Party):
Gladys Block, University of California, Berkeley

Brief Summary:
The purpose of this study is to determine whether or not Vitamin C (1000 mg/day) can reduce markers of inflammation, especially C-reactive protein (CRP), in obese persons with baseline CRP greater than 1 mg/dl.

Condition or disease Intervention/treatment Phase
C-reactive Protein Inflammation Obesity Oxidative Stress Dietary Supplement: Vitamin C (ascorbic acid) Dietary Supplement: Placebo tablet Phase 3

Detailed Description:

The long-term objective of this project is to identify nutritional factors that can reduce the inflammatory component of obesity. Therapies to minimize obesity-related comorbidities are needed, and targeting inflammation may help slow the progression of obesity towards cardiovascular disease and insulin resistance.

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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 512 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Obesity, Inflammation and Oxidative Stress
Study Start Date : January 2010
Actual Primary Completion Date : July 2012
Actual Study Completion Date : July 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin C
U.S. FDA Resources

Arm Intervention/treatment
Placebo Comparator: Placebo
Two tablets, daily, for 8 weeks
Dietary Supplement: Placebo tablet
Placebo tablet (two 500-mg tablets), 8 weeks
Experimental: Vitamin C
Two tablets, daily, for 8 weeks
Dietary Supplement: Vitamin C (ascorbic acid)
1000 mg/day (two 500-mg tablets), 8 weeks

Primary Outcome Measures :
  1. high-sensitivity C-reactive protein [ Time Frame: After 8 weeks of intervention ]

Secondary Outcome Measures :
  1. CRP-related markers of inflammation and oxidative stress, including cytokines and F2-isoprostanes. [ Time Frame: After 8 weeks of intervention. ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • BMI ≥ 30
  • hsCRP ≥ 1 mg/L
  • Age 18+
  • Member of Kaiser Permanente Health Plan of Northern California

Exclusion Criteria:

  • Smoker
  • 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

Information from the National Library of Medicine

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 identifier (NCT number): NCT01028976

United States, California
Kaiser Permanente of Northern California, Division of Research
Oakland, California, United States, 94612
Sponsors and Collaborators
University of California, Berkeley
Kaiser Permanente
Principal Investigator: Gladys Block, PhD University of California, Berkeley

Responsible Party: Gladys Block, Professor Emerita, University of California, Berkeley Identifier: NCT01028976     History of Changes
Other Study ID Numbers: DK062378-05
First Posted: December 9, 2009    Key Record Dates
Last Update Posted: December 2, 2015
Last Verified: November 2015

Keywords provided by Gladys Block, University of California, Berkeley:
randomized controlled trial
primary prevention
Vitamin C
C-reactive protein
anti-inflammatory agents

Additional relevant MeSH terms:
Nutrition Disorders
Body Weight
Signs and Symptoms
Pathologic Processes
Ascorbic Acid
Growth Substances
Physiological Effects of Drugs
Molecular Mechanisms of Pharmacological Action
Protective Agents