Diaphragmatic Straightness In 302 Asbestos-Exposed Patients

Our plain-English summary of Diaphragmatic Straightness In 302 Asbestos-Exposed Patients, by A. Hirsch, L. Di Menza, A. Carre, et al (1980).

The study

• Authors: A. Hirsch, L. Di Menza, A. Carre, F. Dorbon, J. Bignon
• Published: Biological Effects Of Mineral Fibres (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 30, Pp. 523-526 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002177. The article is still under copyright, so we describe it here rather than post it.

In plain English

This study, from a respiratory research laboratory in Créteil, France, looked at an X-ray sign the authors call diaphragmatic straightness: one or more flat stretches that interrupt or replace the normal curve of the diaphragm, with no thickening. It covered 302 people in four groups: 48 patients having chest surgery (37 with bronchial carcinoma), 172 asbestos-exposed electric-power plant workers, 36 hospitalized patients with asbestos-caused respiratory diseases, and 46 asbestos-spray workers. The authors judged exposure to rise from the first group to the last. In the surgical group, straightness on X-ray and plaques found by the surgeon on the diaphragm were both present in six cases and both absent in 32. Five had straightness without plaques, and four had plaques without straightness. Except for the spray workers, straightness on side views rose with exposure: 27%, 42% and 69% in the first three groups. Straightness was related to exposure intensity judged by questionnaire. It was not related to ferruginous body counts or to length or latent period of exposure. The authors said the sign may interest public health if confirmed as a sensitive indicator of asbestos exposure.

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: Radiological comparison study of four groups of patients and workers, with comparison against surgical findings in one group
• Who was studied: 302 subjects in France: (A) 48 consecutive thoracotomy patients, 37 with bronchial carcinoma; (B) 172 asbestos-exposed electric-power plant workers; (C) 36 hospitalized patients with asbestos-caused respiratory diseases; (D) 46 asbestos-spray workers. Study dates are not given.
• Exposure: Asbestos exposure (fiber types not stated) among electric-power plant workers, asbestos-spray workers and patients. Intensity was assessed by occupational questionnaire and by ferruginous body counts in sputum or broncho-alveolar lavage fluid, and was judged to increase from group A to group D.
• Main results:
  • Surgical group (A): diaphragmatic straightness on X-ray and surgical diaphragmatic plaques were both present in 6 cases and both absent in 32 cases. 5 had straightness without surgical plaques and 4 had surgical plaques without straightness.
  • Except for group D (spray workers), straightness on lateral X-ray views increased with exposure: group A 27%, group B 42%, group C 69%. Frontal-view figures are partly unreadable in the scan; group A was 29%.
  • Straightness was most often located in the middle of the diaphragm, on both frontal and lateral views.
  • In group C, 42% showed straightness on high-KV frontal views. The authors report that oblique high-KV views allowed better diagnosis of plaques.
  • By questionnaire-assessed exposure intensity (Table 1, 302 subjects), diaphragmatic straightness was seen in 50%, 54% and 56% of the three exposed categories and in 9% of those with exposure absent (p 0.01). Fibrosis was seen in 55%, 31%, 12% and 0% (p 0.001). Pleural thickening was not significantly related.
  • Straightness and fibrosis were related to questionnaire-assessed exposure intensity but not to ferruginous body counts (Table 2, 72 subjects). No relationship was found with length or latent period of exposure.
• The authors' conclusion: The authors concluded that diaphragmatic straightness increased with increasing intensity, but not with length or latency, of asbestos exposure. They suggested it appears to be an earlier sign than diaphragmatic calcification and would be of public health interest if confirmed as a sensitive indicator of asbestos exposure.
• Limitations the authors state:
  • The authors attribute the disagreements between surgical plaques and X-ray straightness to the limits of the surgical and radiological methods. A diaphragm that looks normal at surgery may not be normal under the microscope.

Topics

Medical terms in this study, explained in our Lexicon: Diaphragm, Carcinoma, Ferruginous body, Asbestos Exposure.

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