Abstract / Summary
Abstract Background The systemic manifestations of chronic obstructive pulmonary disease (COPD) are well established, but associations among systemic inflammation, pulmonary function, arterial oxygenation, and attention remain insufficiently characterized in coal miners. Methods This comparative cross-sectional study included 180 male underground coal miners: 90 with occupational COPD and 90 coal-dust-exposed miners without COPD. COPD was staged as GOLD 1–4; all COPD participants had a mixed chronic bronchitic–emphysematous phenotype, and pneumoconiosis and other interstitial lung diseases were excluded radiologically. CRP, total cholesterol, post-bronchodilator FEV₁, PaO₂, and selective attention using the Münsterberg test were assessed. Correlations were examined by group, and adjusted regression, hypoxemia-stratified, and exploratory ROC analyses were conducted within COPD. Results Compared with miners without COPD, the pooled COPD group had higher CRP (2.3 ± 2.5 vs. 0.9 ± 1.4 mg/L) and cholesterol (4.9 ± 0.9 vs. 4.4 ± 0.9 mmol/L), lower FEV₁ (56.0 ± 16.1% vs. 111.8 ± 13.9% predicted) and PaO₂ (64.3 ± 5.5 vs. 82.6 ± 5.2 mmHg; all P < 0.001), and lower attention scores (15.6 ± 4.1 vs. 17.3 ± 4.7 points; P = 0.007). Within COPD, attention correlated with PaO₂ (rₛ = 0.75; P < 0.00001), and participants with PaO₂ < 60 mmHg had lower scores than those with PaO₂ 60–79 mmHg (12.5 ± 3.4 vs. 16.4 ± 3.8; P < 0.001). PaO₂ was the only independently associated variable in the adjusted model (B = 0.528 points/mmHg; 95% CI, 0.406–0.650; P < 0.001). Exploratory discrimination was good (AUC = 0.878; 95% bootstrap CI, 0.762–0.961), but was not externally validated. Conclusions In this cross-sectional occupational sample, lower arterial oxygenation was the most consistent correlate of poorer selective attention among miners with occupational COPD. The observed relationships with CRP, cholesterol, airflow obstruction, and work experience are compatible with the proposed occupational–inflammatory–respiratory framework-decreased attention, but do not establish temporal sequence, mediation, or causality.