Dietary and Genetic Factors in Asthma & Chronic Bronchitis in a Cohort of Chinese Singaporeans

NCT ID: NCT00342030

Last Updated: 2017-07-02

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 63257 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2002-11-01
• Study Completion Date: 2012-04-12

Brief 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.

Conditions

Chronic Bronchitis; Asthma

Eligibility Criteria

Inclusion Criteria

No new subjects are being enrolled for this proposal.

Subjects are the 63,257 participants in the Singapore Chinese Health Study. That study includes men and women aged 45-74 at enrollment of Chinese ethnicity living in Singapore.

• Minimum Eligible Age: 45 Years
• Maximum Eligible Age: 74 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute of Environmental Health Sciences (NIEHS)

NIH

Sponsor Role: lead

Principal Investigators

Frederick W Miller, M.D.

Role: PRINCIPAL_INVESTIGATOR

National Institute of Environmental Health Sciences (NIEHS)

Locations

National University of Singapore

Kent Ridge, , Singapore

Countries

Singapore

References

Buist AS, Vollmer WM. Reflections on the rise in asthma morbidity and mortality. JAMA. 1990 Oct 3;264(13):1719-20. No abstract available.

Reference Type: BACKGROUND

PMID: 2398613 (View on PubMed)

Ng TP, Hui KP, Tan WC. Prevalence of asthma and risk factors among Chinese, Malay, and Indian adults in Singapore. Thorax. 1994 Apr;49(4):347-51. doi: 10.1136/thx.49.4.347.

Reference Type: BACKGROUND

PMID: 8202905 (View on PubMed)

Karjalainen A, Kurppa K, Martikainen R, Klaukka T, Karjalainen J. Work is related to a substantial portion of adult-onset asthma incidence in the Finnish population. Am J Respir Crit Care Med. 2001 Aug 15;164(4):565-8. doi: 10.1164/ajrccm.164.4.2012146.

Reference Type: BACKGROUND

PMID: 11520716 (View on PubMed)

Other Identifiers

03-E-N044

Identifier Type: -

Identifier Source: secondary_id

999903044

Identifier Type: -

Identifier Source: org_study_id