COPD P-004 : The Difference on Chest CT Findings of COPD Patients Considering Regional Effect: Urban and Rural Area Near Cement Plant with Specific Dust Exposure

Purpose The clinical and radiological presentation of chronic obstructive pulmonary disease (COPD) has proposed heterogeneity according to the sources of inflammation characterized in COPD. This study tried to evaluate COPD phenotypes for specific dust exposure. Method This study was designed to compare characteristics and clinical outcomes with radiological findings between the two prospective COPD cohorts representing a distinguishing region in the Korea; COPD in Dusty Area (CODA) and the Korean Obstructive Lung Disease (KOLD) cohort. A total of 733 participants (n=186 for CODA, and n=547 for KOLD, for each) were included in the final analysis. Multivariate analysis for the comparison of lung function and CT measurements of both study groups after adjusting for age, gender, education, body mass index, smoking status, pack-year, charlson comorbity index, and the frequency of exacerbation were done entering the level of FEV1(%), biomass exposure and COPD medication into the model in stepwise. Result There was no differences in mean wall area (70.2±1.26 in CODA vs. 67.07±0.90 in KOLD, p=0.121). KOLD, where the COPD subjects from urban and metropolitan area, showed higher emphysema index (6.07±3.06 in CODA vs. 20.0±2.21 in KOLD, p<0.001, respectively). This significance in emphysema index was consistent even after further adjustment for FEV1 (6.12±2.88 in CODA vs. 17.3±2.10 in KOLD, p=0.002, respectively). Mean wall area was also found to be significantly lower in KOLD (70.2±1.21 in CODA vs. 66.8±0.88 in KOLD, p=0.028) after including FEV1 into the model. However, there was no difference in lung density between the two groups (p=0.077). Additional adjustment for biomass parameter and medication for COPD did not alter the statistical significance after entering into the analysis with COPD medication. Conclusion Higher mean wall area and lower emphysema index were observed in dust exposure region. These Results suggest that imaging phenotype of COPD is influenced by the environmental exposure.