Examining the Role of Vitamin D in Asthma and Chronic Obstructive Pulmonary Disease (COPD)
Condition: Asthma; Pulmonary Disease; Chronic Obstructive
MeSH terms: Asthma; Lung Diseases
Study type: Observational

Summary: 
      Asthma and chronic obstructive pulmonary disease (COPD) are diseases that affect a person's
      ability to breathe normally. People who do not receive enough vitamin D may have a higher
      risk of developing asthma or COPD. This study will examine previously collected blood samples
      of participants in three studies to determine whether people with low vitamin D levels have
      an increased risk of severe asthma or COPD.
    

Detailed description: 
      Asthma and COPD are among the leading causes of illness in children and adults, respectively.
      Asthma is the most common long-term disease among children in the developed world, and
      approximately 16 million people in the United States have COPD, which is now the fourth most
      common cause of death in this country. Vitamin D, both a nutrient and a hormone, can be taken
      in through diet and exposure to sunlight. Many children and adults have a vitamin D
      deficiency and there is concern that current recommended intake levels may be inadequate. A
      vitamin D deficiency can cause immune system dysfunction and may increase the risk of
      developing immune-mediated disorders, such as multiple sclerosis, inflammatory bowel disease,
      rheumatoid arthritis, and various cancers. Because of its role in immune development and
      function, a vitamin D deficiency may also be related to the development of severe asthma in
      children and to greater lung function decline in adults, leading to COPD. Preliminary
      research shows that people with asthma who take vitamin D have an enhanced response to
      corticosteroids, a common medication used to treat asthma. This finding suggests that vitamin
      D could possibly be used to improve asthma treatment. The purpose of this study is to measure
      vitamin D levels in participants of three previous studies and determine whether lower
      vitamin D levels are related to the development of severe asthma or COPD.

      This study will examine previously collected blood samples from participants in three
      studies. There will be no study visits specifically for this study. The three studies include
      the following:

        -  Childhood Asthma Management Program, which is a study that examined the use of inhaled
           corticosteroids, nedocromil, and placebo in children with mild-to-moderate asthma

        -  Genetic Epidemiology of Asthma in Costa Rica, which is an ongoing study that is
           identifying genetic predictors of asthma in Costa Rican families with asthma

        -  Normative Aging Study, which is a study of aging that is being conducted in men living
           in Boston
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        For the Childhood Asthma Management Program, the study population was children with mild to
        moderate asthma, 5 to 12 years of age, living across the United States. For the Genetic
        Epidemiology of Asthma in Costa Rica study, the study population was children with asthma,
        5 to 12 years of age, living in Costa Rica. For the Normative Aging Study, the study
        population was a community sample of men living in the Boston area.
      
Biospecimen description: 
      Serum samples
    
Keywords: Lung Function Decline; Lung Function; Allergy; COPD; Vitamin D