An observational study in Asthma, sponsored by Imperial College London. Completed at 1 site in United Kingdom. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-10-21.
Sponsored by Imperial College London · Observational
The purpose of this study will be to determine whether there is any role for measuring Hydrogen Sulphide (H2S) in the exhaled breath in terms of management of the patient with asthma.
The investigators will recruit patients with a range of severity of asthma and health volunteers. Levels of Hydrogen Sulphide will be measured in exhaled breath and blood. Also exhaled Nitric Oxide, Spirometry and asthma symptom scores will be measured at each study visit. Participants will attend either 2 or 4 separate visits.
The investigators will determine whether there is a relationship between exhaled Hydrogen Sulphide and asthma severity.
Objectives:
We will recruit 30 health volunteers and 90 patients with a range of severity of asthma.
Particpants will attend for either 2 or 4 visits. At these visits the following measurements will be taken:
The investigators will use a Hydrogen Sulphide UV fluorescent machine Model T101 (0-50 ppb to 0-20 ppm) (Cal-Bay Control Inc, USA) to measure directly on line exhaled breath Hydrogen Sulphide. This method has been used previously in normal people, but we will first determine whether there is an exhaled flow-dependence on the measurement of H2S levels. The investigators will use a hand-held Nitric Oxide machine (NO Breath) to measure Nitric Oxide in exhaled breath.
Subjects must have asthma according to one or more of the following criteria documented in the last 12 months:
PLUS A history of wheeze occurring spontaneously or on exertion
3,921 studies on the registry are indexed under Asthma; 507 are open to participants now.
This study's enrollment of 70 is below the median of 150 across 970 observational studies indexed under Asthma.
Browse Asthma studies →Imperial College London is the lead sponsor of 824 studies on the registry; 178 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
The investigators will recruit a cohort healthy subjects by advertisement within the Hospital and within the general public (by newspaper advertisement). The investigators will also recruit subjects with asthma from paients attending Asthma Clinics at the Royal Brompton and Harefiled NHS Trust.
All patients must be able to give informed consent. The definition of the severity of their asthma will be according to the GINA (Global Initiative for Asthma) guidelines dependent on the amount of therapy needed to control asthma. The investigators will also include at least 45 patients with severe asthma defined on the basis of: Uncontrolled asthma: three or more of the following features present in any week in the previous 4 weeks:
Diagnosis of asthma for the asthma cohort: Subjects must have asthma according to one or more of the following criteria documented in the last 12 months
PLUS a history of wheeze occurring spontaneously or on exertion
Exclusion Criteria:
Healthy subjects will have no significant medical history and no previous history of asthma or other serious illnesses. They should be non-smokers. The investigators willl measure spirometry and ensure that the values lie within the normal predicted range.
Patients diagnosed as having asthma will be recruited from Royal Brompton Hospital Asthma Clinics. These patients will have a range of severity of asthma ranging from mild-moderate to severe asthma patients. The diagnosis of asthma is ascertained as described in the inclusion criteria.
Hydrogen Sulphide in Exhaled Breath
Level of hydrogen sulphide in exhaled breath measured as parts per billion
Time frame: At baseline visit
FEV1
Forced expiratory volume in one second as percent of predicted value (%)
Time frame: At baseline visit
FVC (Forced Vital Capacity)
Forced vital capacity as per cent of predicted
Time frame: At 4 visits which occur during the study duration, up to 1 year
Exhaled Nitric Oxide
Levels of nitric oxide in exhaled breath in parts per billion
Time frame: At 4 visits which occur during the study duration, up to 1 year
Blood Hydrogen Sulpide Level
Hydrogen Sulpide level measurements from blood
Time frame: At 4 visits which occur during the study duration, up to 1 year
| Milestone | Healthy | Mild-moderate | Severe |
|---|---|---|---|
| Started | 20 | 5 | 45 |
| Completed | 20 | 5 | 45 |
| Not completed | 0 | 0 | 0 |
Level of hydrogen sulphide in exhaled breath measured as parts per billion
| parts per billion | Healthy | Mild-moderate | Severe |
|---|---|---|---|
| Hydrogen Sulphide in Exhaled Breath | 5.0 ± 0.6 | 3.2 ± 1.0 | 4.9 ± 1.3 |
Forced expiratory volume in one second as percent of predicted value (%)
| per cent of predicted value | Healthy Subjects | Mild-moderate Asthma | Severe Asthma |
|---|---|---|---|
| FEV1 | 98.9 ± 4.1 | 92.0 ± 11.1 | 73.6 ± 4.3 |
Forced vital capacity as per cent of predicted
| per cent of predicted value (%) | Healthy | Mild-moderate | Severe |
|---|---|---|---|
| FVC (Forced Vital Capacity) | 105.1 ± 4.3 | 97.40 ± 15.3 | 88.22 ± 3.5 |
Levels of nitric oxide in exhaled breath in parts per billion
| parts per billion | Healthy Subjects | Mild-moderate Asthma | Severe Asthma |
|---|---|---|---|
| Exhaled Nitric Oxide | 25.41 ± 6.3 | 39.42 ± 13.6 | 39.45 ± 2.2 |
Hydrogen Sulpide level measurements from blood
No measurements were reported for this outcome.
Collected over 1 year. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Healthy | 0/20 (0%) | 0/20 (0%) | 0/20 (0%) |
| Mild-moderate | 0/5 (0%) | 0/5 (0%) | 0/5 (0%) |
| Severe | 0/45 (0%) | 0/45 (0%) | 0/45 (0%) |
| Age, Continuous(years) | Healthy | Mild-moderate | Severe | Total |
|---|---|---|---|---|
| Mean | 51.1 ± 3.5 | 55.6 ± 5.9 | 55.9 ± 11.5 | 54.5 ± 9.1 |
| Sex: Female, Male(Participants) | Healthy | Mild-moderate | Severe | Total |
|---|---|---|---|---|
| Female | 13 | 3 | 31 | 47 |
| Male | 7 | 2 | 14 | 23 |
| Race and Ethnicity Not Collected(Participants) | Healthy | Mild-moderate | Severe | Total |
|---|---|---|---|---|
| Count of participants | — | — | — | 0 |
| Region of Enrollment(participants) | Healthy | Mild-moderate | Severe | Total |
|---|---|---|---|---|
| United Kingdom | 20 | 5 | 45 | 70 |
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Imperial College London