Asbestos-Related Pleural Thickening is Independently Associated With Lower Levels of Lung Function and with Shortness of Breath

Abstract

This study investigated the relative contribution of asbestos-related pleural thickening (PT) to lung function indices and to respiratory symptoms. A group of 828 former asbestos cement workers enrolled in a cross-sectional and cohort study of respiratory morbidity and submitted to a detailed occupational history, respiratory symptoms questionnaire, spirometry, postero-anterior chest x-ray, and high-resolution computed chest tomography (HRCT). Asbestos exposure was assessed by years of exposure (a semi-quantitative method), cumulative exposure, and latency time from first exposure. Smoking was assessed in pack-years. PT and asbestosis were assessed according to HRCT criteria. Statistical analysis included descriptive analysis, univariate and multivariate analysis of variance for comparisons of factors related to PT, stepwise multiple regression analysis for continuous dependent variables, and logistic regression analysis for dichotomous dependent variables. Mean age was 51.4 (SD 10.5) years, mean years of exposure 12.4 (SD 8.8), mean cumulative exposure 79.9 (SD 68.5), and mean latency time 25.2 yr (SD 10.4). Of the 828, 238 (28.7%) were smokers, 288 (34.8%) former smokers, and 302 (36.2%) nonsmokers. PT was present in 246 (29.7%) and asbestosis in 74 (8.9%); 97 (11.9%) had shortness of breath of Grade III or more. PT subjects had lower height-adjusted forced vital capacity (FVC) and forced expiratory volume in I s (FEV1) and lower FEV1/FVC% (p < .00001 for all). Variables significantly related to PT were age (p < .000 1), years of exposure (p < .0000 1), cumulative exposure (p < .00001), latency time (p < .00001), pack-years (p < .0000 1), and asbestosis (p < .00 1). In a multiple stepwise regression model, after controlling for confounders, height adjusted FEV1 and FVC were in versely and significantly associated with PT, mainly when associated with asbestosis. A logistic regression model with shortness of brea th as the dependent va riable, con trolled for confounders, showed that PT was significa ntly associated with the symptom, even without asbestosis. In conclusion, PT is independently associated with lower va lues of FEV1 and FVC. PT is also independently associated with an increased risk of shortn ess of breath report. PT should be considered as a disease for clinical follow up and for compensa tion claims.

Longitudinal decline in lung function in former asbestos exposed workers

“…It is noteworthy that higher scores of pleural thickening conferred substantial losses of FVC, that is, 247 ml in subjects in score 3 (pleural thickening extent 3, affecting both chest walls plus both diaphragms). In a previous cross-sectional report of 828 former A/C workers, the presence of pleural thickening was significantly associated with lower levels of height-adjusted FVC 38. This report also reinforced the detrimental association of higher BMI with lower levels of FVC.…”

High frequency and severity of pleural changes in former workers exposed to anthophyllite associated with other contaminating amphibole asbestos in Brazil

“…Similarly, studies conducted in Brazil in a cohort of asbestos cement workers exposed to various types of asbestos fiber demonstrated an association between reduced values of FVC, adjusted for height, and presence of pleural thickening, confirmed in subsequent analysis by the association of FVC decline with the extent of pleural thickening. The small number of workers followed in our study might explain the absence of significant decrease in the lung function parameters.…”

Causes of death in former asbestos‐cement workers in the state of São Paulo, Brazil

“…Detailed cohort descriptions were previously published in studies that assessed the frequency of nonmalignant respiratory morbidities related to asbestos and longitudinal changes in lung function. [20][21][22] In summary, workers answered a structured respiratory symptoms questionnaire, including data on smoking, chest auscultation, spirometry, and chest imaging. A detailed occupational history, including age at first exposure, year of first exposure, and exposure duration, was obtained.…”