title: Emphysema and Airflow Obstruction in Non-Smoking Coal Miners with Pneumoconiosis.
abstract: BACKGROUND Accumulating evidence shows that functional impairment in subjects with coal workers' pneumoconiosis (CWP) is principally due to emphysema and airflow obstruction, rather than underlying restrictive mechanisms. However, cigarette smoking has remained a major confounder. The aim of this study was to assess whether coal dust exposure was associated with emphysema and/or airflow obstruction in the absence of smoking history. MATERIAL AND METHODS The subjects evaluated for possible pneumoconiosis between 2013 and 2015 were retrospectively enrolled into this study. After excluding those with history of smoking, tuberculosis, or lung cancer, the study population was a total of 57 subjects. The emphysema severity and airflow obstruction were quantified by computed tomographic densitometry analysis and spirometry, respectively. For comparability regarding emphysema, 9 age- and sex-matched nonsmoker (n=9) control subjects without known lung disease were randomly selected from a radiology database. RESULTS Emphysema severity was significantly higher in the CWP group compared with the control group (15% vs. 4%, p<0.001). The median percent emphysema and percentage of those with FEV1/FVC <0.7 was 13% and 37% in subjects with simple CWP and 18% and 67% in subjects with complicated CWP, respectively. Percent emphysema and Perc15 (15th percentile of the attenuation curve) was correlated with FEV1/FVC (r=-0.45, r=-0.47) and FEF25-75 (r=-0.36, r=-0.56), respectively, but not with perfusion score. A linear regression analysis showed that factors associated with emphysema were FEV1/FVC (β=-0.24, p=0.009) and large opacity (β=-3.97, p=0.079), and factors associated with FEV1/FVC were percent emphysema (β=-0.51, p=0.018) and tenure (β=-0.63, p=0.044). CONCLUSIONS Our results support the observation that coal dust exposure is associated with emphysema and airflow obstruction, independent of smoking status.
authors.affiliation: Department of Pulmonary Medicine, Bulent Ecevit University, School of Medicine, Zonguldak, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Altınsoy
authors.affiliation: Department of Radiology, Bulent Ecevit University, School of Medicine, Zonguldak, Turkey.
authors.forename: İbrahim İlker
authors.initials: İİ
authors.lastname: Öz
authors.affiliation: Department of Pulmonary Medicine, Bulent Ecevit University, School of Medicine, Zonguldak, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Erboy
authors.affiliation: Department of Pulmonary Medicine, Bulent Ecevit University, School of Medicine, Zonguldak, Turkey.
authors.forename: Meltem
authors.initials: M
authors.lastname: Tor
authors.affiliation: Department of Pulmonary Medicine, Bulent Ecevit University, School of Medicine, Zonguldak, Turkey.
authors.forename: Figen
authors.initials: F
authors.lastname: Atalay
mesh_terms: D000368:Aged; D055008:Anthracosis / Q000150:complications / Q000503:physiopathology*; D016022:Case-Control Studies; D003032:Coal Mining; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D000067572:Miners; D009784:Occupational Diseases / Q000209:etiology / Q000503:physiopathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000209:etiology / Q000503:physiopathology*; D012189:Retrospective Studies; D012907:Smoking; D014797:Vital Capacity