Changing patterns in asbestos-induced lung disease.
OBJECTIVE
To determine patterns in asbestos-induced lung diseases found in older, less exposed workers.


METHODS
Review of a database evaluating lung function, smoking status, form of asbestos-induced lung disease, and radiograph abnormalities.


METHODS
Outpatient clinic.


METHODS
A total of 3383 asbestos-exposed workers referred for independent medical evaluation, including control subjects who lacked asbestos-specific radiograph abnormalities (n = 243), subjects with low International Labor Organization (ILO) scores (n = 2,685), high ILO scores (n = 312), bronchogenic cancer (n = 63), and mesothelioma (n = 80). Of these, 3,327 workers have specific smoking status information and 3,312 workers have lung volume measures.


METHODS
Chest radiographs were interpreted by a certified B-reader, and abnormalities were quantified according to the ILO scoring system. Spirometry and lung volume measurement were performed. Subjects completed a self-administered questionnaire that was reviewed at the time of examination. Control subjects were screened on two separate occasions at least 10 years apart to exclude subclinical or slowly progressive asbestos-induced lung disease.


RESULTS
The mean age of the population was 65.1 +/- 9.9 years, and the latency was 41.4 +/- 10.1 years (+/- SD). Most subjects (41.8%) had normal pulmonary function. Obstruction was the most common pulmonary function abnormality (25.4%), followed by restriction (19.3%) and a mixed pattern (6.0%). Most subjects (79.4%) had low ILO scores. Benign pleural abnormalities were the only findings in 54% of subjects with low ILO score. Subjects with high ILO scores were older, smoked more, and had a longer latency than subjects with low ILO scores and control subjects. Smokers were younger, had a shorter latency, and had paradoxically greater ILO scores than nonsmokers. Subjects with bronchogenic cancer and mesothelioma had longer latencies than control subjects and subjects with benign asbestos-induced lung disease.


CONCLUSIONS
Asbestos-induced lung disease today is characterized by low ILO scores, long latencies, greater disease magnitude in smokers, and a normal or obstructive pattern of pulmonary function abnormality. Spirometric evaluation in the absence of lung volume measurements caused misclassification that resulted in overestimation of the presence of a restrictive pattern of pulmonary function.
Ohar
Jill
J
Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1054, USA. johar@wfubmc.edu
Sterling
David A
DA
Bleecker
Eugene
E
Donohue
James
J
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001194:Asbestos / Q000009:adverse effects*; D001195:Asbestosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology*; D001707:Biopsy, Needle; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D011336:Probability; D011379:Prognosis; D012044:Regression Analysis; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects*; D013147:Spirometry; D014057:Tomography, X-Ray Computed
D001194:Asbestos