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Genetics of Airway Responsiveness and Lung Function

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00005537
First Posted: May 26, 2000
Last Update Posted: March 16, 2016
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
  Purpose
To perform a genome-wide search for genes affecting two phenotypes related to asthma and chronic obstructive pulmonary disease (COPD) in a Chinese population.

Condition
Asthma Lung Diseases, Obstructive Chronic Obstructive Pulmonary Disease

Study Type: Observational

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: July 1997
Study Completion Date: June 2002
Detailed Description:

DESIGN NARRATIVE:

Airway responsiveness and lung function, endpoints with a strong genetic basis, are central to the obstructive airway diseases (asthma and COPD). In contrast, the dissection of the underlying genes requires unique sample resources, accurate and comprehensive phenotyping, and an efficient study design. To address to this three-pronged challenge, a genomic screen brought together a large, homogenous, mostly untreated sample from Anhui, China, a wealth of expertise in asthma phenotypes, and a potent study design based on extreme discordant sib pairs.

Since this approach utilized an extant asthmatic family population, no support for data collection was required. The primary focus of the study was two intermediate phenotypes related to asthma and COPD: airway responsiveness (characterized by increased responsiveness to histamine methacholine or other nonspecific agonists and measured by the slope of the dose response relationship) and forced expiratory volume in 1 second (FEV1). Since both traits are continuous, the appropriate study design considered only siblings with extremely discordant phenotypes. For many studies, this strategy was not feasible due to the thousands of families that must be phenotyped to identify a sample of such siblings. The plan was to utilize the organization of a well-established network in China to collect 150 extreme discordant sib pairs of each intermediate phenotype. For airway responsiveness, the estimated power from this sample, equivalent to roughly 600 concordant sib pairs, was intended to surpass the power of all existing studies, including the U.S. Collaborative Study on the Genetics of Asthma. Further, with similar power, this was the first study to test for linkage to FEV1. Moreover, to further augment power, potential phenotypic heterogeneity was reduced by stratifying the analyses by total and specific serum IgE levels, skin test reactivity, peripheral blood eosinophilia, respiratory symptoms, age, gender, bronchodilator response, and cigarette smoking.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria
No eligibility criteria
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00005537


Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Investigators
OverallOfficial: Xiping Xu Brigham and Women's Hospital
  More Information

Publications:

ClinicalTrials.gov Identifier: NCT00005537     History of Changes
Other Study ID Numbers: 5071
R01HL056371 ( U.S. NIH Grant/Contract )
First Submitted: May 25, 2000
First Posted: May 26, 2000
Last Update Posted: March 16, 2016
Last Verified: August 2004

Additional relevant MeSH terms:
Lung Diseases
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases