TABLE 1

Associations of PM_2.5 deposition in the total lung and alveolar region of five lung lobes with lung function and percent emphysema in 86 COPD patients

	Mean±sd	Multivariate, beta coefficient (95% CI)
		Total lung	Alveolar region
		Total lung	Left upper lobe	Left lower lobe	Right upper lobe	Right middle lobe	Right lower lobe
Mean±sd PM_2.5 deposition in lung regions, µg·m⁻³		27.99±3.36	4.17±0.50	8.14±0.98	4.69±0.56	2.50±0.30	8.49±1.02
Lung function
FEV₁, %	56.6±19.8	−0.710 (−1.960–0.541)
FEV₁, L	1.3±0.5	−0.022 (−0.053–0.009)
FEV₁/FVC, %	52.3±10.0	−0.356 (−0.991–0.279)
Percent emphysema
Emphysema severity, point	2.1±0.5	0.059 (0.029–0.090)*
Total lung LAA, %	15.6±9.4	1.296 (0.782–1.811)*
Left upper lobe LAA, %	17.0±11.7		9.962 (5.523–14.402)*
Left lower lobe LAA, %	14.0±11.1			4.492 (2.314–6.671)*
Left lung LAA, %	15.8±10.8		9.561 (5.518–13.603)*	4.897 (2.824–6.970)*
Right upper lobe LAA, %	16.5±11.2				7.795 (4.039–11.552)*
Right middle lobe LAA, %	17.3±10.4					13.658 (6.964–20.353)*
Right lower lobe LAA, %	13.1±9.1						3.294 (1.646–4.942)*
Right lung LAA, %	15.4±9.0				6.888 (3.914–9.863)*	12.952 (7.366–18.537)*	3.804 (2.157–5.450)*

Adjusted for age, sex, body mass index, and smoking pack-years. Values in bold characters are deemed statistically significant. FEV₁: forced expiratory volume in the first second; FVC: forced vital capacity; LAA: low attenuation area; PM_2.5: particles with a 50% cut-off aerodynamic diameter of 2.5 μm. *: p<0.05.