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Bronchial hyperreactivity is associated with enhanced grain dust-induced airflow obstruction
J N Kline1, P J Jagielo, J L Watt
1Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA. joel-kline@uiowa.edu
Journal of Applied Physiology (Bethesda, Md. : 1985)
|August 24, 2000
Summary
Individuals with bronchial hyperreactivity (BHR) experience greater lung function decline after corn dust exposure, but show similar airway inflammation compared to healthy individuals. This suggests BHR primarily impacts airflow limitation, not the inflammatory response itself.
Area of Science:
- Occupational Medicine
- Pulmonary Immunology
- Environmental Health
Background:
- Bronchial hyperreactivity (BHR) is linked to airway inflammation in asthma and occupational exposures.
- Grain dust exposure is known to cause respiratory symptoms and potentially BHR.
Purpose of the Study:
- To investigate the relationship between BHR and pulmonary inflammation following occupational corn dust exposure.
- To compare physiological and inflammatory responses to corn dust extract (CDE) in subjects with and without BHR.
Main Methods:
- An inhalation challenge study using corn dust extract (CDE) was conducted.
- Seven subjects with BHR and seven matched controls were exposed to CDE.
- Physiological parameters (FEV(1)) and bronchoalveolar lavage fluid inflammatory markers were assessed.
Main Results:
- Subjects with BHR reported more chest tightness and dyspnea post-CDE exposure.
- A significantly greater decline in forced expiratory volume in 1 second (FEV(1)) was observed in the BHR group up to 4 hours.
- While inflammation markers increased in all subjects, no significant differences were found between BHR and control groups.
Conclusions:
- Bronchial hyperreactivity (BHR) leads to a more pronounced airflow limitation (FEV(1) decline) after corn dust exposure.
- The underlying pulmonary inflammatory response to corn dust extract appears similar in individuals with and without BHR.