Effect of Dietary Supplements With Fish Oil on Mannitol-induced Airway Sensitivity & Inflammation in Persons With Asthma

• Status: Completed
• Trial end date: 2012-03-01
• Target enrollment: 0
• Participant gender: All

Summary

We wish to investigate the effects of 3 weeks of orally administered fish oil supplements on the airway sensitivity (provoking dose to cause a 15% fall in FEV1, PD15) to inhaled mannitol (AridolTM). Mannitol, an osmotic stimulus has been demonstrated as a useful model for exercise-induced asthma. We also wish to investigate if there is any associated improvement associated with selected markers of airway inflammation that can be measured in the sputum, blood, urine and exhaled breath condensate. Oral fish oil supplements have recently been demonstrated to be effective inhibitors of exercise-induced asthma, in association with an inhibition of markers of inflammation, over a 3 week treatment period. This finding has important implications in the treatment of asthma as this is a faster and more effective improvement than what is seen with inhaled corticosteroids on exercise-induced asthma. This observation requires validation and further investigation. We wish to study this in two patient groups; (a) steroid naïve asthmatics taking beta2 agonist when required and (b) asthmatics taking regular inhaled corticosteroids < 1000 mcg/day.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Firestone Institute for Respiratory Health
• Collaborator: McMaster University
• Treatments: Mannitol

Criteria

Inclusion Criteria:

• Male or female (medically or surgically postmenopausal or practicing an accepted form of barrier or hormonal contraception) subjects age 18-55.

• Stable, mild atopic asthma with forced expiratory volume in one second (FEV1) greater than 70% of predicted for age and height, and not requiring any medical treatment other than short acting inhaled beta2-agonists as required or for those on steroids, taking < 1000 mcg of inhaled corticosteroid per day.

• No recent or significant history of cigarette smoking (no smoking within six months prior to entry into the study; less than 10 pack-years cumulative history of cigarette smoking).

• Signed written informed consent to participate in the study; ability to return to the clinic for repeated visits.

• No history of asthma exacerbations or acute intercurrent respiratory illness (viral respiratory syndrome, bronchitis, pneumonia) for a four week period preceding entry into the screening phase of the study.

• Subjects who take inhales steroids regularly must demonstrate reproducibility to inhaled mannitol (PD15<1.0 doubling doses) during a 2 week run-in period.

• A PD15 to the mannitol challenge < 315mg

Exclusion Criteria:

• Significant gastrointestinal (including hepatic), hematological, cardiovascular, cerebrovascular, metabolic such as including type II diabetes or other body system disorder.

• Regular consumption of fish consisting more than 1 meal of fish per week or regular fish oil supplements during the trial and for at least 2 weeks prior to the first study visit.

• Subjects who have taken oral corticosteroids or a leukotriene receptor antagonist in 4 weeks prior to entry into the study.

• Psychosis, alcoholism, active substance abuse, or any personality disorder, which would make compliance with this protocol problematic.

• Pregnant or nursing females.

• Any other medical or social condition which, in the opinion of the investigator, could confound the interpretation of the data derived from this study.

• Subjects taking >1000 mcg of inhaled steroids daily in those subjects taking inhaled steroids.

• Subjects requiring regular anti-histamines for allergies.

• Subjects who have allergy to fish or any other ingredient in the study products.

• Subjects using anti-coagulants (warfarin, heparin)

• Subjects who have surgery planned over the course of the trial.

• Subjects who use medications to lower LDL cholesterol levels

• Subjects using non-steroidal anti-inflammatory medications (e.g., aspirin, ibuprofen)