Magnesium and Asthma - Clinical Trials
Condition: Asthma
MeSH terms: Asthma
Study type: Interventional
Phase: Phase 2

Summary: 
      Asthma currently affects an estimated 15 million Americans. A number of studies have found an
      association between low dietary magnesium (Mg) intake and increased asthma incidence and
      severity of symptoms. However, clinical intervention trials are necessary to directly assess
      whether there is a true protective or preventative causal relationship between low Mg and
      asthma. In our study, we will assess the effects of 6 1/2 months of oral Mg supplements or
      placebo on clinical markers of asthma control, indirect biomarkers of inflammation, bronchial
      hyperresponsiveness, and indices of oxidative defense and damage in subjects with mild to
      moderate persistent asthma.
    

Detailed description: 
      Over the past twenty years a number of studies of acute bronchial asthma have shown that i.v.
      or nebulized MgS04 may improve symptoms over a course of hours. With respect to dietary
      supplementation, short term (3 wk) oral Mg has been associated with a significant decrease in
      symptoms but no significant effect on measurements like FEV1 or bronchial hyperreactivity by
      methacholine challenge. Although a large number of studies have attempted to address this
      issue, we believe that major gaps still exist. One of the gaps is in the comparison of large
      numbers of asthmatics and non-asthmatics, with regard to dietary intake, and a variety of
      measures of Mg status. We will evaluate baseline Mg intake (diet, tap and bottled drinking
      water, vitamin-mineral supplements, laxatives, and antacids), and multiple measures of Mg
      status, such as total and free serum Mg, total erythrocyte Mg, and Mg retention after an IV
      Mg load in subjects with and without asthma. Furthermore there are no large-scale studies
      evaluating the effects of Mg supplementation on asthma control and clinical markers, and
      markers of inflammation. We propose to assess the effects of 6 1/2 months of oral Mg on
      clinical markers of asthma control (asthma symptom diary, monthly spirometry, asthma quality
      of life questionnaire (QOL)), indirect biomarkers of inflammation (exhaled nitric oxide and
      serum eosinophil cationic protein) and bronchial hyperresponsiveness (methacholine
      challenge)in subjects with mild to moderate persistent asthma. Dietary Mg will be assessed
      using the 24 hr recall. Our hypotheses are that 1.) subjects with mild to moderate persistent
      asthma, as defined by National Institutes of Health National Asthma Education and Prevention
      Program (NIH NAEPP) clinical guidelines will have poorer Mg status than nonasthmatics, and
      2.) that marginal Mg intake and status may modulate the severity of asthma. Thus, subjects
      with asthma who have marginal intake/status and thus relatively lower total and free plasma
      Mg, lower erythrocyte total Mg, and higher Mg retention will show improvement in the
      aforementioned clinical and indirect biomarkers. In contrast, Mg supplements will have little
      effect in subjects with highest intakes and Mg status. We do not anticipate that Mg
      supplementation will replace conventional treatment, but may complement and decrease the need
      for conventional medication.
    

Intervention name(s): Magnesium
Intervention type(s): Drug
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double
Primary purpose: Treatment