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Effects of L-arginine Supplementation in Adults With Moderate to Severe Asthma

This study has been completed.
Sponsor:
Collaborator:
National Institutes of Health (NIH)
Information provided by (Responsible Party):
Nicholas Kenyon, University of California, Davis
ClinicalTrials.gov Identifier:
NCT00280683
First received: January 19, 2006
Last updated: July 2, 2012
Last verified: July 2012
History of Changes
  Purpose

Nitric oxide is an important marker of airway inflammation in asthma. Nitric oxide may have a protective role in patients with moderate to severe asthma. The investigators believe that a natural amino acid, L-arginine, that augments nitric oxide levels can decrease asthma exacerbations and improve the asthma care of moderate to severe asthma patients.

This study is a randomized, placebo controlled trial in which subjects will receive either 3 months of L-arginine supplementation or a placebo. The investigators will monitor subjects' symptoms, the number of asthma exacerbations, and lung function. In addition, we will draw blood, obtain induced sputum samples and measure exhaled breath nitric oxide levels at each monthly visit.


Condition Intervention Phase
Asthma
 Drug: L-Arginine
 Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Phase 2 Study: GCRC: Effects of L-arginine Supplementation on Exhaled Nitric Oxide and Clinical Exacerbations in Adults With Moderate to Severe Asthma

Resource links provided by NLM:

MedlinePlus related topics: Asthma
U.S. FDA Resources

Further study details as provided by University of California, Davis:

Primary Outcome Measures:
  • Number of asthma exacerbations in 3 months [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  • asthma exacerbations [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Lung function [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  • Exhaled nitric oxide levels [ Time Frame: 3 months ] [ Designated as safety issue: No ]

Enrollment: 20
Study Start Date: December 2004
Study Completion Date: December 2008
Primary Completion Date: November 2008 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: L-Arginine
    subjects will take L-arginine orally, at 0.1 g/kg/ day, in divided doses, for 3 months.
Detailed Description:

The primary objective of this 3 month clinical study is to determine if supplemental L-arginine can decrease the number of asthma exacerbations in patients with severe asthma. L-arginine, a natural amino acid, produces nitric oxide (NO) when it is converted to L-citrulline in the presence of the nitric oxide synthase enzymes. We and others have found that NO can protect against allergic airway inflammation, airway hyperresponsiveness and airway fibrosis in various animal models. In addition, we have found that arginase I expression correlates strongly with the lymphocyte and eosinophil influx into the lung and this enzyme may regulate the airway inflammatory response. Our central hypothesis is that L-arginine will increase NO levels in the lung and decrease the number of acute exacerbations of asthma. It may do this by either decreasing the number of Th2 lymphocytes or down-regulating arginase I expression or both.

Our specific aims are, therefore,

  1. To test the hypothesis, in a randomized, double-blinded, placebo controlled trial, that 3 months of L-arginine supplementation will decrease the number of acute asthma exacerbations in severe asthmatic patients,
  2. To determine whether L-arginine decreases the ratio of peripheral blood Th2 to Th1 lymphocytes and
  3. To determine whether L-arginine will modulate serum arginase I/II levels and their downstream products.

Patients will be recruited primarily from the UC Davis Asthma Network (UCAN) clinics, which focus on the care of severe asthmatics, and the study will be performed at the UC Davis/VA General Clinical Research Center.

  Eligibility

Ages Eligible for Study:   18 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Moderate to severe persistent asthma
  • Subject is stable on same asthma medications for at least one month
  • If the subject is a woman of child-bearing age, a negative pregnancy test

Exclusion Criteria:

  • Less than 18 yrs/ age
  • Baseline Forced Expiratory Volume in 1 second (FEV1) <40% predicted
  • Known or suspected allergy to L-arginine
  • Pregnant women, nursing women, or women actively trying to achieve pregnancy
  • Current smokers
  • Subjects with more than a 15 pack-year history of smoking
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00280683

Locations
United States, California
University of California, Davis General Clinical Research Center
Sacramento, California, United States, 95817
Sponsors and Collaborators
University of California, Davis
National Institutes of Health (NIH)
Investigators
Principal Investigator: Nicholas Kenyon, MD University of California, Davis
  More Information

No publications provided

Responsible Party: Nicholas Kenyon, Associate Professor of Medicine, University of California, Davis
ClinicalTrials.gov Identifier: NCT00280683     History of Changes
Other Study ID Numbers: K30-04-Z001
Study First Received: January 19, 2006
Last Updated: July 2, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by University of California, Davis:
Airway Inflammation
Moderate persistent asthma
Severe Persistent Asthma

Additional relevant MeSH terms:
Asthma
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
 Respiratory Hypersensitivity
Hypersensitivity, Immediate
Hypersensitivity
Immune System Diseases

ClinicalTrials.gov processed this record on May 19, 2013