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Increased Decline in Pulmonary Function Among Employees in Norwegian Smelters Reporting Work-Related Asthma-Like
Vidar Søyseth1, Helle Laier Johnsen, Paul K Henneberger
1Department of Medicine (Drs Søyseth, Johnsen, and Kongerud), Faculty Division Akershus University Hospital, University of Oslo, Lørenskog, Norway; Faculty of Medicine (Dr Søyseth), University of Oslo, Oslo, Norway; National Institute of Occupational Health (Dr Johnsen), Oslo, Norway; National Institute for Occupational Safety and Health (Dr Henneberger), Centers for Disease Control and Prevention, Morgantown, W Va; and Departement of Respiratory Medicine (Dr Kongerud), Faculty Division Rikshospitalet Radiumhospitalet, University of Oslo, Oslo, Norway.
Objective:
To investigate associations between work-related asthma-like symptoms (WASTH) and annual pulmonary function decline among employees of 18 Norwegian smelters.
Methods:
A 5-year longitudinal study in which WASTH was defined as a combination of dyspnea and wheezing that improved on rest days and vacation.
Results:
A total of 12,966 spirometry examinations were performed in 3084 employees. Crude annual decline in forced expiratory volume in 1 second (FEV1) (dFEV1) was 32.9 mL/yr (95% confidence interval, 30.5 to 35.3), and crude annual decline in forced vital capacity (FVC) (dFVC) was 40.9 mL/yr (37.8 to 43.9). After adjustment for relevant covariates, employees reporting WASTH showed higher dFEV1 by 16.0 m:/yr (3.4 to 28.6) and higher dFVC by 20.5 mL/yr (6.0 to 35.0) compared with employees not reporting WASTH.
Conclusion:
Work-related asthma-like symptom was associated with greater annual declines in FEV1 and FVC, indicating a restrictive pattern.

