Obesity, Inflammation and Oxidative Stress

Obesity Clinical Trial

Official title:

Obesity, Inflammation and Oxidative Stress

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01028976
• Other study ID #: DK062378-05
• Status: Completed
• Phase: Phase 3
• First received: December 8, 2009
• Last updated: November 30, 2015
• Start date: January 2010
• Est. completion date: July 2012

Study information

• Verified date: November 2015
• Source: University of California, Berkeley
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 512
• Est. completion date: July 2012
• Est. primary completion date: July 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• C-reactive Protein
• Inflammation
• Obesity
• Oxidative Stress

Intervention

Dietary Supplement:
• Vitamin C (ascorbic acid)
1000 mg/day (two 500-mg tablets), 8 weeks
• Placebo tablet
Placebo tablet (two 500-mg tablets), 8 weeks

Locations

Country	Name	City	State
United States	Kaiser Permanente of Northern California, Division of Research	Oakland	California

Sponsors (2)

Lead Sponsor	Collaborator
University of California, Berkeley	Kaiser Permanente

Country where clinical trial is conducted

United States, 

References & Publications (2)

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. — View Citation

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	high-sensitivity C-reactive protein		After 8 weeks of intervention	No
Secondary	CRP-related markers of inflammation and oxidative stress, including cytokines and F2-isoprostanes.		After 8 weeks of intervention.	No