Asthma
Conditions
Keywords
asthma, sleep apnea
Brief summary
We hypothesize that the nocturnal use of continuous positive airway pressure in adults and children with asthma will decrease airway reactivity.
Detailed description
Deep inspirations have been shown to decrease the sensitivity of airways to narrowing (airway reactivity) after inhalation of agents that induce constriction of the bronchi in healthy adults. This response is absent in adult asthmatics; however, there is data demonstrating that use of continuous positive airway pressure (CPAP) for short periods of time may decrease airway reactivity in adult asthmatics. This suggests that although deep inspirations may not result in decreased airway reactivity, sustained lung inflation may lead to changes in asthmatic airway smooth muscle structure that lead to a decrease in airway reactivity. The purpose of our study is to determine whether short and long term use of CPAP in children and adults leads to decreased airway reactivity. If airway reactivity is decreased with CPAP, this may provide a novel therapeutic strategy for patients with asthma.
Interventions
DEVICECPAP-Continuous Positive Airway Pressure
Cpap will be worn at night by subjects 6 to 7 days duration.
DEVICESHAM
SHAM will be worn at night by subjects 6 to 7 days duration.
Sponsors
Indiana University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
8 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
Inclusion criteria for children 8-18 * Children 8-18 years of age scheduled to start CPAP for obstructive sleep apnea. * Subjects can have clinically stable asthma, with no plans by their physician to change asthma therapy over the next month Inclusion criteria adults 18-60 * Adults 18-60 years of age, seen in adult Pulmonary Clinic for sleep related problems who may require treatment with nocturnal continuous positive pressure (CPAP), which will be determined by polysomnography(PSG) will be approached to participate in the study.
Exclusion criteria
Exclusions for Children category age 8-18 include: 1. Cyanotic congenital heart disease. 2. History of acute respiratory symptoms for 3 weeks prior to testing. 3. Inability to perform pulmonary function testing adequately. 4. Escalation in asthma medication at time of recruitment. 5. SaO2 \<93% while awake and breathing room air 6. Baseline FEV1 \<75% predicted Exclusions for adults 18-60 include: 1. Gastro-Esophageal Reflux requiring Medical management. 2. Chronic Obstructive Pulmonary Disease. 3. Use of Supplemental Oxygen. 4. Ischemic Heart Disease or Hypertension requiring treatment with medications other than diuretics. 5. Use of systemic corticosteroid therapy during the past 6 months. 6. Acute Respiratory Illness in the previous 8 weeks. Exclusions/Inclusion criteria for adults with asthma include: 1. Juniper Score \<1.5 2. Baseline FEV1 \> or equal to 70% 3. Non-smoking for 6 months 4. Less than 10 pack year smoking history 5. No change in asthma medications for the last 2 months 6. Negative pregnancy test 7. Subject cannot have sleep apnea
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Provocative Concentration of Methacholine Causing a 20% Fall in Forced Expiratory Volume in 1 Second (FEV1) | 7 to 10 nights after cpap is started. | Methacholine is an inhaled medication used to assess asthma and reactive airways. It was given at increasing concentrations (beginning with 0.0625 mg/ml and ending with 16.0 mg/ml). Each dose was followed by a lung measurement until a change of FEV1 of 20% occurs or until a maximum dose was reached, whichever came first. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| CPAP Subjects used CPAP set at 8-10 cmH20 for 7-10 nights. | 16 |
| Sham Subjects used SHAM set at 0-2 cmH20 for 7-10 nights | 9 |
| Total | 25 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 0 | 2 |
Baseline characteristics
| Characteristic | CPAP | Sham | Total |
|---|---|---|---|
| Age, Continuous | 27 years STANDARD_DEVIATION 6 | 32 years STANDARD_DEVIATION 9 | 29 years STANDARD_DEVIATION 7 |
| Sex: Female, Male Female | 11 Participants | 6 Participants | 17 Participants |
| Sex: Female, Male Male | 5 Participants | 3 Participants | 8 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 16 | 0 / 9 |
| serious Total, serious adverse events | 0 / 16 | 0 / 9 |
Outcome results
Primary
Change in Provocative Concentration of Methacholine Causing a 20% Fall in Forced Expiratory Volume in 1 Second (FEV1)
Methacholine is an inhaled medication used to assess asthma and reactive airways. It was given at increasing concentrations (beginning with 0.0625 mg/ml and ending with 16.0 mg/ml). Each dose was followed by a lung measurement until a change of FEV1 of 20% occurs or until a maximum dose was reached, whichever came first.
Time frame: 7 to 10 nights after cpap is started.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| CPAP | Change in Provocative Concentration of Methacholine Causing a 20% Fall in Forced Expiratory Volume in 1 Second (FEV1) | 0.406 log mg/ml | Standard Error 0.066 |
| Sham | Change in Provocative Concentration of Methacholine Causing a 20% Fall in Forced Expiratory Volume in 1 Second (FEV1) | 0.003 log mg/ml | Standard Error 0.193 |