Bronchial Challenge Test of Magnesium-treated Asthmatics

Study Overview
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Brief Summary
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The present study is part of a project titled 'Magnesium in asthma and chronic obstructive pulmonary disease'. The hypothesis of the main project is that a daily magnesium supplement will benefit patients with asthma and chronic obstructive pulmonary disease. The aim of this part of the project is to study the effect of a daily magnesium supplement on the grade of bronchial hyperreactivity in asthmatics.

Official Title
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Metacholine-provocation of Mablet-treated Asthmatics

Conditions
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Asthma

Intervention / Treatment
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* Dietary Supplement: Magnesium supplement (magnesium hydroxide/ -oxide)
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Asthma with annual symptoms, bronchial hyperreactivity and positive metacholine-test (PD20<1000 microgram Exclusion Criteria: Se-Mg > 2,00 mmol/L, smoking cessation less than 1 year prior to study start, major changes in eating habits within three months prior to study start and during the study period of approx. one year, various conditions (e.g. gastrointestinal disease, kidney disease, pregnancy/lactation) that may affect the study results.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Washout<br> | |
| Active Comparator: Mablet<br> | Dietary Supplement: Magnesium supplement (magnesium hydroxide/ -oxide)<br>* 3 tablets of Mablet (360 mg per tablet) daily for 12 weeks Produced by: Gunnar Kjems APS<br>* Other names: Mablet;|
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* 3 placebo-tablets daily for 12 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PD20 for metacholine | Bronchial hyperreactivity is expressed by the dose of inhaled metacholine necessary to achieve a decline of 20 % in FEV1 (Bronchial challenge test). | Two years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Impulse Oscillometry for measurement of pulmonary impedance | A characteristic feature of Impulse Oscillometry is that pulmonary impedance is not derived from the respiratory signals but from the pressure-flow relationship of artificial impulse-shaped test signals which are produced by an external generator. The advantage of artificial test signals is the incomparably higher frequency contents with a relatively high consistency as far as frequency range and amplitude are concerned, so that a thorough differentiation of pulmonary function is possible. | Two years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bronchial challenge test, Hyperreactivity, PD20 for metacholine, Daily magnesium supplement