Table 2. Protein expression of PARC in lung tissue and intercostal arteries, according to groups.

Tissue	Parameters	COPD	NOS	NS	Overall P-value
Lung
	Number of arteries measured in each subject	10.2±1.6	12.4±1.6	9.9±1.9	0.365
	% Positive immunoreaction	72.3 ± 8.1	57.6 ± 8.1	42.9 ± 9	0.063
	Endothelial layer *	0.02 ± 0.03	0.07 ± 0.03	0.08 ± 0.03	0.443
	Intimal thickening *	0.20 ± 0.07	0.13 ± 0.07	0.16 ± 0.08	0.772
	Muscular layer *	1.23 ± 0.15	0.86 ± 0.15	0.61 ± 0.16	0.023
	Adventitial layer*	0.15 ± 0.08	0.1 ± 0.08	0.05 ± 0.09	0.68
	Alveolar parenchyma*	1.33 ± 0.13	1.13 ± 0.13	0.83 ± 0.15	0.059
	Bronchial structures
	% Positive immunoreaction	79.9 ± 9	59.9 ± 8.7	68.7 ± 9.4	0.293
	Bronchial epithelium*	0.59 ± 0.12	0.41 ± 0.12	0.6 ± 0.12	0.441
	SEBM*	0.1 ± 0.06	0.05 ± 0.06	0.03 ± 0.06	0.7
	Connective tissue*	0.49 ± 0.14	0.53 ± 0.14	0.3 ± 0.15	0.511
	ASM*	0.1 ± 0.08	0.21 ± 0.08	0.03 ± 0.08	0.242
Intercostal artery
	Endothelial layer*	0.38 ± 0.2	0.31 ± 0.23	0.33 ± 0.24	0.975
	Intimal thickening*	0.31 ± 0.16	0.15 ± 0.18	0.42 ± 0.19	0.597
	Muscular layer*	1.19 ± 0.23	1.08 ± 0.26	1.58 ± 0.27	0.362
	Adventitial layer*	0.56 ± 0.17	0.54 ± 0.19	0.75 ± 0.2	0.694

Data are presented as LSM ± SEM. The reported p-value comes from the overall comparison with ANCOVA method with a general linear model using as covariables: gender, pack-years and the presence of diabetes mellitus.

*Label intensity was scored as negative (0), mild (1), moderate (2), and strongly positive (3). The percentage of positive structures and the average score were computed for pulmonary muscular arteries and bronchial structures in each subject. COPD: Chronic Obstructive Pulmonary Disease; NOS: non-obstructed smokers; NS: never-smokers.