To compare the levels of vitamin D in subjects with non-atopic asthma to those in subjects with atopic asthma and those in healthy non-atopic subjects
ID
Source
Brief title
panama deel 5
Condition
- Bronchial disorders (excl neoplasms)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The difference between vitamin D levels of patients with non-atopic asthma and
and patients with atopic asthma and the difference between vitamin D levels of
patients with non-atopic asthmaand healthy non-atopic subjects .
Secondary outcome
virus serology
Genetic tests
Pulmonary function testing: spirometry
ACQ (asthmatic patients)
Medical consumption (asthmatic patients)
Time spent outdoors
Background summary
Vitamin D levels have been linked to asthma and respiratory tract infections.
The mechanism of this association is not yet totally understood, but vitamin D
seems to have an immune modulatory effect and play a role in host defence
against infections. The role of vitamin D in asthma, could especially be
important in non-atopic patients, since non-atopic asthma often starts after a
respiratory tract infection. Data on vitamin D levels in non-atopic asthma are
lacking. By comparing vitamin D levels in non-atopic asthma patients to those
in atopic asthmatics and in healthy non-atopic controls , the role of vitamin D
might be better understood. We hypothesize that vitamin D levels in non-atopic
asthma are lower than those in atopic asthmatics and healthy non-atopic
controls .
Study objective
To compare the levels of vitamin D in subjects with non-atopic asthma to those
in subjects with atopic asthma and those in healthy non-atopic subjects
Study design
Case-control study
Study burden and risks
Most patients with asthma can control their disease with inhalation medication
and have relative few complaints. Some patients, in particular those with
non-atopic asthma, can*t control the disease with the usual medication and need
other therapies. Recently vitamin D has raised interest, since low levels of
vitamin D are related to markers of asthma severity, respiratory tract
infections and impaired steroid responsiveness, all factors that are
characteristic of non-atopic asthma. We hypothesize that decreased levels of
vitamin D play a crucial role in non-atopic asthma and if the case,
supplementation of vitamin D might become a promising alternative in this
subset of asthmatic patients. However, until now data on vitamin D levels in
non-atopic asthma are lacking. For a better understanding it is necessary to
determine if there is a difference in vitamin D levels between non-atopic and
atopic asthmatics and between non-atopic asthmatic patients and non-atopic
healthy subjects.
Patients with non-atopic asthma are already included in a large cohort study.
They will fill out one extra questionnaire. Participants in the other groups
will also fill out this questionnaire. They will be questioned about pulmonary
complaints and history. Also blood will be drawn and a short pulmonary test
will be performed. The total visit will take about 30 minutes.
Altogether we think that this study can help to understand the role of vitamin
D in asthma and hopefully, eventually, improve asthma therapy. Therefore we
think the discomfort for study subjects is justified by the possible benefits
for (non-atopic) asthmatic patients.
Postbus 888
8901BR Leeuwarden
NL
Postbus 888
8901BR Leeuwarden
NL
Listed location countries
Age
Inclusion criteria
Group 1:
- Outpatients with non-atopic asthma, determined by negative alatop
- Age * 18 yrs
- Pulmonologist*s diagnosis of asthma
- Documented reversibility in FEV1 of > 12% predicted OR airway hyperresponsiveness to inhaled methacholine
Group 2:
- Outpatients with atopic asthma, determined by known positive alatop or skin prick test
- Age * 18 yrs
- Pulmonologist*s diagnosis of asthma
- Documented reversibility in FEV1 of > 12% predicted OR airway hyperresponsiveness to inhaled methacholine
Group 3:
- Subjects without pulmonary history or pulmonary complaints
- Age * 18 yrs
- No signs of allergy and negative alatop
- Normal spirometry
Exclusion criteria
Group 1:
- Patients with smoking history of > 10 packyears and persistent airflow obstruction (post bronchodilator FEV1 < 80%pred): excluded if reversibility in FEV1 < 12% predicted OR TLCO < 80%pred
- Pregnancy
- Use of supplements containing vitamin D analogues in the last 6 months
- Other pulmonary diseases
Group 2:
- Patients with smoking history of > 10 packyears and persistent airflow obstruction (post bronchodilator FEV1 < 80%pred): excluded if reversibility in FEV1 < 12% predicted OR TLCO < 80%pred.
- Pregnancy
- Use of supplements containing vitamin D analogues in the last 6 months
- Other pulmonary diseases
Group 3:
- Pulmonary history or current pulmonary complaints
- Use of supplements containing vitamin D analogues in the last 6 months
- Pregnancy
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| CCMO | NL33519.099.10 |
| OMON | NL-OMON20191 |