Effect of occupational exposures on decline of lung function in early chronic obstructive pulmonary disease.
BACKGROUND
Several occupational exposures adversely affect lung function.


OBJECTIVE
This study reports the influence of continued occupational dust and fume exposures on the rate of decline of lung function in participants with early chronic obstructive pulmonary disease (COPD) studied in a population-based study.


METHODS
Subjects consisted of 5,724 participants in the Lung Health Study, a multicenter study of smoking cessation and anticholinergic bronchodilator administration in smokers with early COPD (3,592 men; 2,132 women). Average post-bronchodilator FEV1 at entry was 78.4% predicted for men and 78.2% predicted for women; all participants had an FEV1/FVC ratio less than 0.70.


RESULTS
Participants underwent a baseline evaluation and five annual follow-up assessments, including questionnaires and spirometry. The effect of ongoing dust or fume exposure on FEV1 in each follow-up year was statistically evaluated with a mixed-effects regression model, which was adjusted for FEV1 at entry, age, airway responsiveness to methacholine, baseline smoking intensity, and time-varying (yearly) smoking status during each follow-up year. In men with early COPD, each year of continued fume exposure was associated with a 0.25% predicted reduction in post-bronchodilator FEV1% predicted. Continued smoking and airway hyperresponsiveness were also associated with reduction in FEV1 during each year of follow-up in both men and women. Statistically significant effects of dust exposure on the rate of decline were not found, nor were effects of fume exposure noted in women.


CONCLUSIONS
These results suggest a need for secondary prevention by controlling occupational fume exposures.
Harber
Philip
P
Division of Occupational and Environmental Medicine, David Geffen School of Medicine at University of California, Los Angeles, California 90024, USA. pharber@ucla.edu
Tashkin
Donald P
DP
Simmons
Michael
M
Crawford
Lori
L
Hnizdo
Eva
E
Connett
John
J
D000328:Adult; D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use; D004391:Dust; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D009812:Odorants; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000503:physiopathology*; D016540:Smoking Cessation; D014797:Vital Capacity / Q000502:physiology
D001993:Bronchodilator Agents; D004391:Dust