Patterns of pulmonary dysfunction in asbestos workers: a cross-sectional study

Abstract

BackgroundRestrictive patterns of pulmonary function abnormalities associated with asbestos exposure are well described. Studies are less consistent, however, regarding the association of asbestos inhalation with airway dysfunction and obstructive impairment.MethodsWe compared pulmonary function test results between 277 chrysotile exposed workers (22% non-smokers) and 177 unexposed controls (50.3% non-smokers). Information on exposure and smoking were collected using a standardized questionnaire. Standardized spirometric and DCLO Measurement methods were utilized. CXRs were read based on ILO pneumoconiosis guidelines.ResultsAsbestos exposed subjects had significantly reduced FVC, FEV1, FEV1/FVC and DLCO. Restricting the analysis to non-smokers, asbestos workers still had about 3% lower FEV1/FVC ratio than controls, but this difference did not reach statistical significance. Among exposed workers, the presence of radiographic evidence of asbestosis further lowered FVC and DLCO but not FEV1/FVC compared to asbestos exposure without radiographic asbestosis. Additionally, smoking asbestos workers had significantly lower DLCO compared to non-smoking workers.ConclusionAsbestos exposure, especially when radiographic evidence of interstitial fibrosis from asbestosis is present, leads to significant decreases in FVC, FEV1 and the DLCO. However, asbestos exposure alone is not significantly associated with a reduction of the FEV1/FVC. Smoking-asbestos workers had significantly lower DLCO than their non-smoking counterparts. Whether asbestos interacts with smoking additively or synergistically on DLCO needs further investigation. Similarly, further studies are needed to assess the progression and clinical significance of asbestos induced airway dysfunction.

Association between increased small airway obstruction and asbestos exposure in patients with asbestosis

“…Pleural abnormalities associated with asbestos exposure are caused by collagen deposition, which results in subpleural thickening that may subsequently calcify; additionally, the visceral pleura may exhibit parenchymal fibrosis in adjacent subpleural alveoli . Pleural thickening as a marker of asbestos exposure may be induced by relatively low exposure levels in comparison with asbestosis . In our cohort of patients with asbestosis, 88% of patients also had pleural abnormalities.…”

Lung diffusing capacity relates better to short‐term progression on HRCT abnormalities than spirometry in mild asbestosis

“…Smoking retards the lung clearance of asbestos fibers and may contribute to the severity and progression of asbestosis [Elmes, 1981]. In this context, exposure to cigarette smoking has been described as a confounding factor in the interpretation of HRCTabnormalities in subjects with asbestosis [Vehmas et al, 2003;Abejie et al, 2010]. More recently, Vierikko et al [2008] found that this might be the case even for subjects exposed to secondhand smoking.…”

Lower limit of normal based spirometric abnormalities associated with radiographic abnormality in an elderly cohort at low risk for exposure

“…[9][10][11] The correlation of categorical characterization of lung function abnormality in relatively unexposed workforces with subtle radiographic abnormalities, corresponding to low grade ILO profusion scores has been less extensively studied.…”