Pleural plaques and asbestosis: dose and time-response relationships based on HRCT data

¹ INSERM U954, Vandoeuvre-les-Nancy - France; and Nancy-University, Nancy, France
² INSERM U954, Vandoeuvre-les-Nancy - France
³ LSTE -Occupational Diseases Dept, University Hospital, Bordeaux, France
⁴ Occupational Diseases Dept, University Hospital, Caen, France
⁵ ERSM Rhone-Alpes, Regional Security Insurance, Lyon, France
⁶ Occupational Diseases Dept, AP-HP, Raymond Poincaré Hospital, Garches, France
⁷ IIMTPIF, Paris, France
⁸ Inserm U955, Creteil, France

^* To whom correspondence should be addressed. E-mail: christophe.paris{at}nancy.inserm.fr.

	Abstract

Most studies on asbestos-related diseases are based on chest X-Rays and dose-response relationships are still controversial. The aim of this study was to describe the most relevant parameters of asbestos exposure linked to pleural plaques and asbestosis diagnosed by High Resolution Computed Tomography (HRCT).

A large screening programme including systematic HRCT examinations was organized from 2003 to 2005 in France for former asbestos-exposed workers. Time since first exposure (TSFE), level, duration, and cumulative exposure (CE) to asbestos were used in adjusted unconditional logistic regression to model the relationships of the two diseases.

Analysis of a population of 5,545 subjects demonstrated that TSFE (p<0.0001) and CE (p=0.02) (or level, depending on the models used), were independently associated with the frequency of pleural plaques. Only CE (p<0.0001) or level of exposure (p=0.02) were significantly associated with asbestosis. All trend tests were significant for these parameters.

To date, this study is at our knowledge the largest programme based on HRCT for the screening of asbestos-exposed subjects. Both "time-response" and "dose-response" relationships were demonstrated for pleural plaques, while only "dose-response" relationships were demonstrated for asbestosis. These parameters must be included in the definition of high-risk populations for HRCT-based screening programmes.