Positive Airway Pressure for the Treatment of Asthma

NCT ID: NCT01154699

Last Updated: 2017-05-17

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 31 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2010-07-31
• Study Completion Date: 2014-12-31

Brief Summary

Asthma is an extremely common disorder, which is becoming more prevalent. The purpose of this study is to examine how nocturnal lung volumes contribute to asthma severity, which may explain part of the link between asthma and obesity. The investigators seek to test the hypothesis that raising lung volumes during the night will improve asthma symptoms. The investigators work may lead to new targets for therapy.

Detailed Description

Asthma is a chronic respiratory disease characterized by airway inflammation and airway hyperresponsiveness, which causes airflow obstruction. It is extremely prevalent, affecting an estimated 22 million Americans, and costly with loss of productivity and direct healthcare costs in the billions of dollars. The incidence and prevalence of asthma are increasing, both in the US and around the world. This increase comes despite greater understanding of the inflammatory and allergic basis for asthma, and despite better antiinflammatory medications. One explanation for the increasing prevalence of asthma is the concomitant increase in obesity, with the majority of Americans now overweight or obese. Numerous studies have convincingly linked asthma and obesity, and demonstrated increased obstruction with weight gain and decreased obstruction with weight loss. However, the mechanisms that underlie this linkage are not known.

We believe that low lung volumes contribute to the pathogenesis and severity of asthma. End-expiratory lung volume is decreased in obesity, and likely falls further during sleep, particularly in overweight and obese patients. Both upper and lower airway resistance increase with decreasing lung volumes, as airways become smaller. However, prior work has shown that lower airway resistance increases out of proportion to the decrease in lung volume that occurs during sleep in asthma patients. This difference between controls and people with asthma has not been further explored, yet may provide insight into asthma pathogenesis and provide potential targets for therapy.

Therefore, we propose a series of experiments to define the impact of lung volumes during sleep on airway resistance. One of these experiments will be to to test the hypothesis that lung stretch can be used therapeutically by tonically and dynamically increasing lung volumes during sleep using bi-level positive airway pressure. This research can help delineate asthma pathogenesis and may help improve therapeutic options in this exceedingly common disease.

Conditions

Asthma; Sleep Apnea

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Usual Care first, then Bilevel PAP

Subjects will begin the study by continuing their usual care for 4 weeks. They will complete questionnaires and breathing tests at the start and end of this 4 week period. After a "Washout Period" of an additional 4 weeks of usual care, they will then start Bilevel PAP therapy for 4 weeks. Just before and after the Bilevel PAP they will complete questionnaires and breathing tests.

Group Type: EXPERIMENTAL

Bilevel PAP (4 weeks)

Intervention Type: DEVICE

Subjects will use bilevel PAP each night for 4 weeks. The pressure levels will be adjusted by the investigators to increase lung volumes during the night.

Usual Care (4 weeks)

Intervention Type: OTHER

Subjects will continue with their usual asthma care. Investigators will make no changes to their medications or other habits.

Washout Period (4 weeks)

Intervention Type: OTHER

Subjects will continue with their usual asthma care in between the Usual Care and Bilevel PAP periods. Investigators will make no changes to their medications or other habits.

Bilevel PAP first, then Usual Care

Subjects will begin the study by starting on Bilevel PAP for 4 weeks. Just before and after the Bilevel PAP they will complete questionnaires and breathing tests. After a 4 week "Washout Period" of usual care, they will start a Usual Care period for 4 weeks. They will complete questionnaires and breathing tests at the start and end of this 4 week period.

Group Type: EXPERIMENTAL

Bilevel PAP (4 weeks)

Intervention Type: DEVICE

Subjects will use bilevel PAP each night for 4 weeks. The pressure levels will be adjusted by the investigators to increase lung volumes during the night.

Usual Care (4 weeks)

Intervention Type: OTHER

Subjects will continue with their usual asthma care. Investigators will make no changes to their medications or other habits.

Washout Period (4 weeks)

Intervention Type: OTHER

Subjects will continue with their usual asthma care in between the Usual Care and Bilevel PAP periods. Investigators will make no changes to their medications or other habits.

Interventions

Bilevel PAP (4 weeks)

Subjects will use bilevel PAP each night for 4 weeks. The pressure levels will be adjusted by the investigators to increase lung volumes during the night.

Intervention Type: DEVICE

Usual Care (4 weeks)

Subjects will continue with their usual asthma care. Investigators will make no changes to their medications or other habits.

Intervention Type: OTHER

Washout Period (4 weeks)

Subjects will continue with their usual asthma care in between the Usual Care and Bilevel PAP periods. Investigators will make no changes to their medications or other habits.

Intervention Type: OTHER

Other Intervention Names

Bilevel positive airway pressure

Eligibility Criteria

Inclusion Criteria

• mild to moderate asthma, diagnosed by a physician, OR
• mild to moderate asthma and CPAP treated OSA. Must be compliant with CPAP therapy (greater than 4 hours per night, at least 4 nights/week)

Exclusion Criteria

• lung disease other than asthma or OSA
• medications known to affect respiratory function (apart from asthma and rhinitis therapy)
• abnormal nasal anatomy
• current smokers and ex-smokers (quit within the last 3 months, or >10 pack-years)
• pregnant women - women of child bearing age will undergo a urine pregnancy test before enrollment and during the course of the study, as some of the study procedures cannot be performed during pregnancy and because pregnancy often changes asthma symptoms and severity.
• severe asthma - defined as a recent exacerbation (doctor or ER visit for asthma, or oral steroid use, within the previous 4 weeks) or frequent exacerbations (>4 exacerbations in the last year.
• severe obstructive sleep apnea requiring supplemental oxygen in addition to CPAP therapy.
• the regular use of prescription (e.g. zolpidem) or over-the-counter sleep aids (e.g. Benadryl).
• Central sleep apnea

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: collaborator

Brigham and Women's Hospital

OTHER

Sponsor Role: lead

Responsible Party

Robert L. Owens

Instructor in Medicine

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Robert L Owens, MD

Role: PRINCIPAL_INVESTIGATOR

Brigham and Women's Hospital

Locations

Brigham and Women's Hospital

Boston, Massachusetts, United States

Countries

United States

Other Identifiers

1F32HL097578-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

5K23HL105542

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2009-P-001733/1

Identifier Type: -

Identifier Source: org_study_id