Lung function in asbestos-exposed workers, a systematic review and meta-analysis

Abstract

BackgroundA continuing controversy exists about whether, asbestos exposure is associated with significant lung function impairments when major radiological abnormalities are lacking. We conducted a systematic review and meta-analysis in order to assess whether asbestos exposure is related to impairment of lung function parameters independently of the radiological findings.MethodsMEDLINE was searched from its inception up to April 2010. We included studies that assessed lung function parameters in asbestos exposed workers and stratified subjects according to radiological findings. Estimates of VC, FEV1 and FEV1/VC with their dispersion measures were extracted and pooled.ResultsOur meta-analysis with data from 9,921 workers exposed to asbestos demonstrates a statistically significant reduction in VC, FEV1 and FEV1/VC, even in those workers without radiological changes. Less severe lung function impairments are detected if the diagnoses are based on (high resolution) computed tomography rather than the less sensitive X-ray images. The degree of lung function impairment was partly related to the proportion of smokers included in the studies.ConclusionsAsbestos exposure is related to restrictive and obstructive lung function impairment. Even in the absence of radiological evidence of parenchymal or pleural diseases there is a trend for functional impairment.

Reduced lung function in smokers in a lung cancer screening cohort with asbestos exposure and pleural plaques

“…A subgroup analysis designed to compare pulmonary function in those asbestos‐exposed subjects with and without pleural plaques revealed significant decrease in FVC, and a trend for decrease in FEV 1, in those with isolated pleural plaques. This result is consistent with multiple prior studies that demonstrate lower FEV 1 and FVC in cohorts with high levels of asbestos exposure and presence of pleural plaques [Jarvholm and Sanden, ; Oliver et al, ; Bourbeau et al, ; Lilis et al, ; Wilken et al, ; Kopylev et al, ]. Lockey and colleagues [Lockey et al, ] reported a relationship between cumulative fiber exposure and localized pleural thickening at lifetime exposure levels 3–10 times less than the 45‐year working lifetime U.S. Occupational Safety and Health Administration standard of 4.5 fiber‐year/cm 3 for commercial asbestos exposure.…”

“…The American Thoracic Society, in considering pulmonary function changes due to asbestos‐related pleural plaques, concluded that studies of large cohorts showed a significant 5% reduction in FVC attributable to the plaques [ATS Statement, ]. Wilken and colleagues [Wilken et al, ] performed a systematic review and meta‐analysis of 9,921 workers exposed to asbestos and found a statistically significant reduction in FVC in those without radiological changes [94.9% predicted (95%CI 92.9–96.9)], those with pleural fibrosis [87.1% predicted (95%CI 83.9–90.4)], and asbestosis [84.8% predicted (95%CI 80.8–88.8)].…”

Descriptive analysis of the respiratory health status of persons exposed to Libby amphibole asbestos

“…Although the American Thoracic Society Statement41 addresses the relationship of chronic airway obstruction to asbestos exposure, the frequency and severity have been observed to be greater in the Libby cohort. Thus, contributions to significant airway obstruction decreased FEV 1 and/or low FEV 1 /FVC could arise from asbestos42 as well as smoking. Differences in DL CO were associated with gender, age, smoking history and radiographic findings.…”

Commentary to the article lung function not affected by asbestos exposure in workers with normal Computed Tomography scan, by Schikowsky, Felten, et al., 2017

“…It is well‐known that exposure to all kinds of dusts results in a decrease in lung function. There is no reason to assume that this is different for asbestos exposure . The latter is especially clarified in the meta‐analysis of Wilken et al summarizing all available work, demonstrating a small, but statistically significant impairment in FVC, FEV 1 , and FEV 1 /VC in asbestos workers with normal chest X‐ray or Computed Tomography findings (see Figure and Table ).…”