Pleural abnormality as a cause of impairment and disability

Our plain-English summary of Pleural abnormality as a cause of impairment and disability, by P. Ernst, J. Bourbeau, M.R. Becklake (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: P. Ernst, J. Bourbeau, M.R. Becklake
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:157-61
• Type of article: Review
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004852).

In plain English

This short conference paper presented results from the authors' own study, published in full elsewhere (Bourbeau and colleagues, 1990), on whether asbestos-related pleural disease lowers lung function on its own. The study examined 110 active insulation workers from the construction industry, aged 35 to 50, who did not have obvious asbestosis. About 58% had some pleural abnormality, mostly pleural plaques. 5.5% had diffuse pleural thickening shown by blunting of the costophrenic angle. Workers with any pleural change (64) were compared with those without (46). The comparison was adjusted for age, height, smoking, chest X-ray profusion and a gallium lung-scan index of lung-tissue disease. Any pleural abnormality was linked to an average deficit of 200 ml in FEV1 (air blown out in one second) and 400 ml in forced vital capacity. Unilateral costophrenic angle involvement was associated with an average 500-ml reduction in forced vital capacity. The authors could not demonstrate disability on exercise testing. The authors concluded that asbestos-related pleural disease harms lung function, most markedly with costophrenic angle blunting.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional study of an active workforce, comparing workers with and without pleural abnormality using resting and exercise lung function. This paper summarizes results first published by Bourbeau et al. (1990).
• Who was studied: 110 active insulation workers from the construction industry, aged 35 to 50, without obvious asbestosis. 64 had any pleural change and 46 had none. The article does not state where or when the workers were studied.
• Exposure: Work as an insulation worker in the construction industry. Mean years in the trade were 23 for workers without pleural change and 24 for those with pleural change. No fiber types or doses are given.
• Main results:
  • About 58% of the 110 workers had some pleural abnormality, mostly pleural plaques.
  • 5.5% of workers had diffuse pleural thickening, shown by blunting of the costophrenic angle.
  • Ninety percent of workers had a category-0 chest film for parenchymal (lung-tissue) abnormalities. The highest ILO profusion grade was 1/1.
  • Both groups were similar in age, weight, height, smoking and years in the trade. X-ray profusion and gallium index were higher in workers with pleural change, so the lung comparisons were adjusted for these.
  • After adjusting for age, height, smoking, X-ray profusion and gallium index, any pleural abnormality was associated with an average FEV1 deficit of 200 ml.
  • After the same adjustment, forced vital capacity (FVC) was on average 400 ml lower in workers with any pleural abnormality.
  • The largest deficit was seen with costophrenic angle blunting. Unilateral costophrenic angle involvement was associated with an average 500-ml reduction in FVC.
  • The only exercise abnormality was excessive ventilation as a percentage of predicted. The authors were unable to demonstrate any disability on exercise testing.
• The authors' conclusion: The authors concluded that asbestos-related pleural disease has a detrimental effect on the level of lung function, and that this effect is most pronounced in workers with costophrenic angle blunting, a marker of diffuse pleural fibrosis.
• Limitations the authors state:
  • The workers were relatively young and active and did not report exercise limitation. The authors said this makes the lack of a demonstrable exercise disability unsurprising.
  • The excess ventilation finding was partly due to the fact that predicted ventilation is based on measured vital capacity.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis.

Related studies

• The relationship between respiratory impairment and asbestos-related pleural abnormality in an active work force — J. Bourbeau, P. Ernst, et al. (1990)
• Causes of pulmonary impairment in asbestos-exposed individuals with diffuse pleural thickening — S.T. Kee, G. Gamsu, et al. (1996)
• Between- and within-reader variability in the assessment of pleural abnormality using the ILO 1980 international classification of pneumoconioses — J. Bourbeau, P. Ernst (1988)
• Do asbestos-related pleural plaques on HRCT scans cause restrictive impairment in the absence of pulmonary fibrosis? — B. Clin, C. Paris, et al. (2011)
• The relationship between respiratory impairment and asbestos-related pleural abnormality in an active work force — J.E. Cotes, B. King (1991)
• Exercise impairment in asbestos-induced pleural fibrosis. Is it really just interstitial fibrosis? — E.T. Mannix, W.J. Martin (1994)

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