Small airway changes in workers exposed to asbestos

Our plain-English summary of Small airway changes in workers exposed to asbestos, by A. Miller (Respiration; International Review of Thoracic Diseases, 1985).

The study

• Author: A. Miller
• Journal: Respiration; International Review of Thoracic Diseases
• Published: 1985;48(2):190-1
• Type of article: Letter
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001259).

In plain English

This item was a letter to the editor, not an original study. The author, of the Mount Sinai Medical Center in New York, disputed a 1984 paper in the same journal by Cohen et al. that reported 'small airway changes' in asbestos-exposed workers. The author objected that Cohen et al.'s subjects were successful litigants, not a meaningful sample of exposed workers. The author added that the paper gave no data on asbestos exposure (fiber type, fiber burden, industries or processes) or on clinical and X-ray findings. Citing Cohen et al.'s figures for nonsmokers exposed over 30 years, the author noted mean FVC was 79.7% of predicted, versus 85.5% for FEV1, 84.7% for MEFR and 88.1% for FEF75%. The author argued this pattern indicated restrictive rather than obstructive impairment. The author also noted two things. Nonsmokers employed 15 to 30 years had FVC, FEV1 and flows as good as or better than those employed under 15 years. Smokers did as well as or better than nonsmokers on FEF75%. The author concluded that the paper did not provide meaningful information.

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: Letter to the editor critiquing a previously published study (Cohen et al., Respiration 1984); no new data
• Who was studied: No population of its own. The letter discusses the subjects of Cohen et al.'s study, whom the author describes as successful litigants.
• Exposure: Asbestos exposure in Cohen et al.'s subjects. The author states that the paper gave no details of fiber type, fiber burden, industries or processes.
• Main results:
  • Citing Cohen et al.'s data for nonsmokers exposed more than 30 years: mean FVC was 79.7% of predicted, versus 85.5% for FEV1, 84.7% for MEFR and 88.1% for FEF75%. The author argued this indicates restrictive rather than obstructive impairment.
  • The author noted that in Cohen et al.'s data, nonsmokers employed 15 to 30 years had FVC, FEV1 and flows better than or about the same as those employed less than 15 years. The author called this at variance with the dose-response relationship found in other studies.
  • The author pointed out that Cohen et al. found FEF75% significantly reduced only in workers exposed more than 30 years. The author considered this inconsistent with published evidence that small airways obstruction is an early change.
  • The author noted that in Cohen et al.'s data, FEF75% was consistently better or the same in smokers compared with nonsmokers. This was despite smoking being, in the author's words, the most prevalent cause of small airways obstruction.
  • The author argued that Cohen et al.'s additional measures (increased CC and a nitrogen-based measure) reflect elastic properties of the lung. In the author's view, they cannot show small airways obstruction when FVC is decreased.
• The authors' conclusion: The author concluded that Cohen et al.'s paper did not provide meaningful information about small airways in asbestos workers. The author stated that it could even be used to argue that such changes do not exist.

Related studies

• Inhalation of rod-like carbon nanotubes causes unconventional allergic airway inflammation — E.M. Rydman, M. Ilves, et al. (2014)
• Cigarette smoke increases the penetration of asbestos fibers into airway walls — D. McFadden, J. Wright, et al. (1986)
• Real-time non-invasive detection of inhalable particulates delivered into live mouse airways — M. Donnelley, K.S. Morgan, et al. (2009)
• Pathologic changes in the small airways of the guinea pig after amosite asbestos exposure — D. Filipenko, J.L. Wright, et al. (1985)
• Railroad workers with pleural plaques: II. Small airway dysfunction among asbestos-exposed workers — U. Hjortsberg, P. Orbaek, et al. (1988)
• Does asbestos exposure (asbestosis) cause (clinical) airway obstruction (small airway disease)? — A. Miller, W.N. Rom (2010)

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