Dietary Supplementation With Soy Isoflavones in Asthma

NCT00277446 | Completed Results

• 1 other identifier: 0456-035
• Study Type: interventional
• Target: 13
• Locations: 1 country
• Sites: 1

Brief Summary

An epidemiologic study of patients with asthma has shown that increased intake of soy isoflavones correlates with less severe asthma. In experimental animals, treatment with the soy isoflavone genistein reduces airways inflammation and hyper-responsiveness. In vitro studies performed by us have shows that genistein reduces release of inflammatory compounds by human blood eosinophils. The purpose of this pilot study is to determine whether dietary supplementation with soy isoflavones has effects in patients with asthma. 20 patients with asthma will supplement their diet with a soy isoflavone capsule for 4 weeks. Before and after the supplementation period, we will measure lung function, exhaled nitric oxide (a marker for airway inflammation), collect exhaled breath condensate to measure levels of inflammatory mediators in the airways, and isolate peripheral blood eosinophils to assess the impact of soy isoflavones on their function. We hypothesize that dietary supplementation with soy isoflavones will reduce exhaled nitric oxide level, reduce the inflammatory mediators in the exhaled breath condensate, and reduce the ability of eosinophils to release inflammatory molecules. Identifying if these hypothesized effects of soy isoflavones exist in asthma will provide a justification for further clinical studies.

Conditions

Asthma

Keywords

Asthma; Soy isoflavones; Eosinophils; Exhaled nitric oxide

Outcome Measures

Primary Outcomes (1)

• Exhaled Nitric Oxide

  Exhaled nitric oxide at baseline (week 0) and at 4 weeks

  0 and 4 weeks

Secondary Outcomes (2)

• Eosinophil LTC4 Synthesis

  0 and 4 weeks

• Forced Expiratory Volume in One Second (FEV1)

  0 and 4 weeks

Interventions

Soy isoflavones DRUG

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Ages 18-50, males and females
• Physician diagnosis of asthma; requires daily asthma medication
• Moderate persistent disease (NAEPP guidelines)
• FEV1 65 to 90% of predicted
• At least 12% increase in FEV1 15-30 minutes after inhaling 2-4 puffs of albuterol or positive methacholine challenge (20% fall in FEV1 at less than 8 mg/ml) - either of these can available from the previous 2 years
• Generally good health

You may not qualify if:

• Oral corticosteroid use within the past 3 months
• Use of high dose inhaled corticosteroids (greater than 500 mcg of fluticasone per day or greater)
• Current or former smoker (quit less than 6 months prior to study enrollment or greater than 10 pack years)
• Recent asthma exacerbation (within 6 weeks)
• Current consumption of soy isoflavone supplements
• Known adverse reaction to genistein, other phytoestrogens, or soy products
• Pregnant
• Unintentional weight loss of more than 10 pounds within the year
• Major or unstable medical condition
• Use of an investigational drug in the previous 30 days

Sponsors & Collaborators

• Northwestern University: lead

Study Sites (1)

Northwestern University

Chicago, Illinois, 60611, United States

Location

MeSH Terms

Conditions

Asthma

Interventions

Soybean Proteins

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Intervention Hierarchy (Ancestors)

Plant Proteins; Proteins; Amino Acids, Peptides, and Proteins; Plant Proteins, Dietary; Dietary Proteins; Food; Diet, Food, and Nutrition; Physiological Phenomena; Soy Foods; Vegetable Products; Vegetables; Food and Beverages

Results Point of Contact

• Title: Lewis J. Smith
• Organization: Northwestern University

ljsmith@northwestern.edu

312-503-0501

Study Officials

• Lewis J Smith, MD

  Northwestern University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: January 13, 2006
• First Posted: January 16, 2006
• Study Start: January 1, 2006
• Primary Completion: April 1, 2007
• Study Completion: April 1, 2007
• Last Updated: February 25, 2011
• Results First Posted: February 24, 2011

Record last verified: 2011-02

Locations

US (1)