Asbestos-induced visceral pleural fibrosis reduces pulmonary compliance

Our plain-English summary of Asbestos-induced visceral pleural fibrosis reduces pulmonary compliance, by E.H. Valkila, M.M. Nieminen, A.K. Moilanen, et al (American Journal of Industrial Medicine, 1995).

The study

• Authors: E.H. Valkila, M.M. Nieminen, A.K. Moilanen, P.A. Kuusisto, A.H. Lahdensuo, J.I. Karvonen
• Journal: American Journal of Industrial Medicine
• Published: 1995;28(3):363-72
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

To determine the nature of respiratory functional impairment caused by asbestos-induced visceral pleural fibrosis (VPF) and to discover which pulmonary physiological variable best reveals it, we examined 59 asbestos-exposed construction workers having asbestos-related changes on chest radiographs. Computed tomography scans of the thorax were also performed. Visceral pleural fibrosis was diagnosed in 29 subjects: seven had only VPF, 17 had VPF and pleural plaques, and five had VPF, plaques, and asbestosis. In subjects without VPF, 23 had plaques, six had plaques and asbestosis, and one had only minor fibrotic parenchymal changes insufficient for a diagnosis of asbestosis. Flow-volume spirometry, body plethysmography, static and dynamic compliance, and pulmonary diffusing capacity for carbon monoxide were measured. The subjects with VPF had significantly lower static (p = 0.005) and dynamic (p = 0.007) compliance values than those without. Other respiratory function variables failed to show any significant differences. We conclude that the measurement of static and dynamic compliance is a useful method in assessing pulmonary function impairment caused by visceral pleural fibrosis.

In plain English

This Finnish study measured lung function in 59 construction workers with asbestos-related changes on chest X-rays. They were referred from an occupational asbestos screening program to Tampere University Hospital. They were aged 41 to 81, and 93% were male. The article does not name the asbestos fiber types involved. Chest X-rays and CT scans showed visceral pleural fibrosis (scarring of the lung's own lining) in 29 workers (49%); the other 30 did not have it. Many in both groups also had pleural plaques, and some had asbestosis. Workers with visceral pleural fibrosis had significantly lower static (p = 0.005) and dynamic (p = 0.007) lung compliance, a measure of how easily the lungs stretch. Other breathing tests and lung volumes did not differ significantly between the groups. In regression analyses, age and visceral pleural fibrosis were the main factors linked to lower static compliance. Smoking was not linked to compliance values. The authors noted that their models explained only 27% and 20% of the variation in compliance. They concluded that measuring compliance is a useful way to show lung impairment caused by visceral pleural fibrosis when other tests may not yet show differences.

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 clinical comparison of lung function in exposed workers with and without visceral pleural fibrosis, with regression analysis
• Who was studied: 59 asbestos-exposed construction workers in Finland with asbestos-related changes on chest radiographs. They were drawn from 115 workers with an asbestos-induced lung disorder in the Institute of Occupational Health Asbestos Program and examined at Tampere University Hospital. Age range 41 to 81 years, mean age 61.4, 93% male.
• Exposure: Occupational asbestos exposure in construction trades: carpenters, pipefitters, laborers, concrete workers, concrete reinforcement workers, bitumen insulators and a pipe insulator. Duration was estimated in workdays from interviews. Fiber types are not specified.
• Main results:
  • Visceral pleural fibrosis was found on chest radiographs and CT scans in 29 of the 59 subjects (49%).
  • Subjects with visceral pleural fibrosis had significantly lower static (p = 0.005) and dynamic (p = 0.007) compliance than subjects without it.
  • Other lung function variables, including spirometry, lung volumes and diffusing capacity, showed no significant differences between subjects with and without visceral pleural fibrosis.
  • In multiple regression, age and visceral pleural fibrosis were the most important factors explaining reduced static compliance. The association of visceral pleural fibrosis with dynamic compliance had p = 0.065.
  • Pack-years of smoking and the presence of pleural plaques showed no correlation with compliance values.
  • Age was the only significant factor explaining reduced forced vital capacity (FVC).
• The authors' conclusion: The authors concluded that measuring static and dynamic compliance is a useful method for demonstrating lung function impairment caused by visceral pleural fibrosis, when other methods may not yet show significant differences.
• Limitations the authors state:
  • The regression models explained only 27% of the variation in static compliance and 20% in dynamic compliance.
  • Asbestosis was not included in the regression analyses because only 11 subjects had it.

Topics

Medical terms in this study, explained in our Lexicon: Fibrosis, Chest X-Ray, Thorax, Pleural Plaques, Spirometry, Diffusing Capacity (DLCO).

Related studies

• Mineral fibres, fibrosis, and asbestos bodies in lung tissue from deceased asbestos cement workers — M. Albin, L. Johansson, et al. (1990)
• Epithelial-mesenchymal transition involved in pulmonary fibrosis induced by multi-walled carbon nanotubes via TGF-beta/Smad signaling pathway — T. Chen, H. Nie, et al. (2014)
• Cytokine regulation of lung fibroblast proliferation. Pulmonary and systemic changes in asbestos-induced pulmonary fibrosis — I. Lemaire, H. Beaudoin, et al. (1986)
• Changes in autacoid and neuropeptide contents of lung cells in asbestos-induced pulmonary fibrosis — R. Day, S. Lemaire, et al. (1987)
• Immunoregulation of lung fibroblast growth: alteration in asbestos-induced pulmonary fibrosis — I. Lemaire, C. Dubois, et al. (1986)
• The validity of static lung compliance in asbestos-induced diseases — J. Schneider, R. Arhelger, et al. (2012)

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