Dietary and Genetic Factors in Asthma & Chronic Bronchitis in a Cohort of Chinese Singaporeans
Condition: Chronic Bronchitis; Asthma
MeSH terms: Bronchitis; Bronchitis, Chronic; Asthma; Acute Disease
Study type: Observational

Summary: 
      There is suggestive evidence for a role of dietary in the etiology of asthma and chronic
      bronchitis. However, there are few prospective data. We propose to expand our collaboration
      with the Singapore Chinese Health Study to examine dietary, environmental, and genetic
      factors, along with their interactions, in relation to the risk of developing asthma and
      chronic bronchitis. The Singapore Chinese Health Study is a cohort of 63,257 men and women of
      Chinese ethnicity in Singapore who were aged 45-74 years at enrollment from 1993 to 1998.
      Telephone follow-up of the cohort to update and outcome information began in 1999 and is
      ongoing. We expect to identify 538 cases of incident asthma and 672 cases of incident chronic
      bronchitis when the current follow-up questionnaire cycle is complete in 2004. In this
      proposal, we would validate self-reports of incident asthma, obtain follow-up data from the
      entire cohort to perform analyses of dietary and smoking in relation to these outcomes, and
      analyze genetic material on cases of incident asthma and chronic bronchitis and controls from
      the cohort. In this proposal we will examine the following hypotheses:

        1. Higher intake of fruits and/or antioxidant micronutrients decreases the risk of
           developing asthma and chronic bronchitis.

           a. Effects if fruit and/or antioxidant micronutrients may differ by smoking history.

        2. Common polymorphisms in genes involved in the response to oxidative stress influence the
           risk of asthma and chronic Bronchitis. We initially propose to examine polymorphisms in
           three genes--glutathione S-tranferase M1, glutahione S-transferase P1, and matrix
           metalloproteinase-1. However, we plan to examine additional relevant polymorphisms in
           the future, especially taking advantage of high throughput screens of candidate genes
           for asthma and chronic bronchitis. It is possible that by 2004 when the sample set will
           be available that more compelling candidates and high throughput screens may be
           available to us at a low cost. Thus we will re-evaluate our choice when the samples are
           available.

        3. Polymorphisms in these and other genes interact with fruit/antioxidant intake and/or
           smoking to influence the risk of asthma and chronic bronchitis.
    

Detailed description: 
      There is suggestive evidence for a role of diet in the etiology of asthma and chronic
      bronchitis. However, there are few prospective data. We propose to expand our collaboration
      with the Singapore Chinese Health Study to examine dietary, environmental, and genetic
      factors, along with their interactions, in relation to the risk of developing asthma and
      chronic bronchitis. The Singapore Chinese Health Study (NIH grant CA080205) is a cohort of
      63,257 men and women of Chinese ethnicity in Singapore who were aged 45-74 years at
      enrollment from 1993 to 1998. Telephone follow-up of the cohort to update and outcome
      information began in 1999 and is ongoing. We expect to identify 538 cases of incident asthma
      and 672 cases of incident chronic bronchitis when the current follow-up questionnaire cycle
      is complete in 2004. In this proposal, we would validate self-reports of incident asthma,
      obtain follow-up data from the entire cohort to perform analyses of diet and smoking in
      relation to these outcomes, and analyze genetic material on cases of incident asthma and
      chronic bronchitis and controls from the cohort. In this proposal we will examine the
      following hypotheses:

        1. Higher intake of fruits and/or antioxidant micronutrients decreases the risk of
           developing asthma and chronic bronchitis.

           a. Effects of fruit and/or antioxidant micronutrients may differ by smoking history

        2. Common polymorphisms in genes involved in the response to oxidative stress influence the
           risk of asthma and chronic bronchitis. We initially propose to examine polymorphisms in
           three genes -- glutathione S-tranferase M1, glutathione S-transferase P1, and matrix
           metalloproteinase-1. However, we plan to examine additional relevant polymorphisms in
           the future, especially taking advantage of high throughput screens of candidate genes
           for asthma and chronic bronchitis. It is possible that by 2004 when the sample set will
           be available that more compelling candidates and high throughput screens may be
           available to us at a low cost. Thus we will re-evaluate our choice when the samples are
           available.

        3. Polymorphisms in these and other genes interact with fruit/antioxidant intake and/or
           smoking to influence the risk of asthma and chronic bronchitis.
    

Keywords: Respiratory; Polymorphism; Fruit; COPD; Prospective; Diet