Relationship of pulmonary function to radiographic interstitial fibrosis in 2,611 long-term asbestos insulators. An assessment of the International Labour Office profusion score.
Radiographic evidence of interstitial fibrosis (IF) secondary to asbestos inhalation (using the International Labour Office [ILO] profusion of small irregular opacities) was compared with FVC as an independent indicator of IF. In addition, spirometric indices of airflow (FEV1/FVC and FET25-75%) were correlated with the radiographic profusion score. A study of 2,611 long-term insulators was well designed for these analyses since all subjects were from the same trade, there were sufficient (n = 515) nonsmokers to assess the effects of asbestos exposure in the absence of smoking, most (60%, n = 1,557) of the workers had parenchymal abnormalities (scores greater than or equal to 1/0), and there was a greater prevalence of high scores than in other published series (347 workers or 13.3% had scores greater than or equal to 2/1). Looking at all subjects, the FVC decreased as profusion score increased. The FVC was abnormal (88.0% of predicted) even when the profusion score was clearly normal (0/0). The FVC was lower at any score in smokers and in workers with pleural thickening (more so with diffuse thickening). There was, however, no difference in FVC between intermediate scores 0/1 versus 1/0 and 1/2 versus 2/1. Airflow increased with greater profusion, tending to overcome a decrease seen at lesser profusion scores. These results provide a greater understanding of the relationships among profusion scores, smoking, pleural diseases, and pulmonary function.
Miller
A
A
Department of Community Medicine, Mount Sinai School of Medicine, City University of New York, NY 10029.
Lilis
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R
Godbold
J
J
Chan
E
E
Selikoff
I J
IJ
D001195:Asbestosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008450:Maximal Midexpiratory Flow Rate; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D011859:Radiography; D012907:Smoking; D013147:Spirometry; D014797:Vital Capacity