YKL-40 expression in chronic obstructive pulmonary disease: relation to acute exacerbations and airway remodeling

Respiratory Research

Table 1 Baseline characteristic of subjects

		Patients with COPD			P value
	Controls (n = 47)	All (n = 81)	Stable (n = 44)	Exacerbation (n = 37)	Control vs. all patients	Stable vs. exacerbation
Age, yrs	57.7 ± 1.5	58.3 ± 1.0	56.8 ± 1.3	60.0 ± 1.5	0.402	0.116
Male/female, n	28/19	54/27	27/17	27/10	0.297	0.270
Smoking history, packs/year	37.0 ± 1.7	42.9 ± 1.2	41.6 ± 1.1	44.3 ± 2.3	0.067	0.258
Smoking status Never/current/former, n	25/12/10	0/49/32	0/28/16	0/21/16	0.420	0.528
FEV₁/FVC, %	82.9 ± 0.8	53.1 ± 1.4	56.1 ± 1.8	49.7 ± 2.2	<0.001	0.027
FEV₁, % predicted	96.6 ± 1.6	54.7 ± 2.4	61.4 ± 3.2	46.7 ± 3.3	<0.001	0.002
PaO₂, mmHg	N/D	74.2 ± 1.0	77.5 ± 1.0	70.3 ± 1.5	―	<0.001
PaCO₂, mmHg	N/D	43.1 ± 0.6	40.6 ± 0.7	45.9 ± 0.9	―	<0.001
CRP, mg/L	3.5 ± 0.3	36.7 ± 3.6	14.2 ± 1.1	63.5 ± 4.5	<0.001	<0.001
Severity of COPD^a	N/A				―	0.489
GOLD I/II, n (%)		47 (58.0)	24 (54.5)	23 (62.2)
GOLD III/IV, n (%)		34 (42.0)	20 (45.5)	14 (37.8)
COPD treatments, n (%)	N/A				―	0.935
ICS/LABA		58 (71.6)	32 (72.7)	26 (70.3)
SABA or SAMA		71 (87.7)	38 (86.4)	33 (89.2)
Theophylline		51 (63.0)	29 (65.9)	22 (59.5)

Data are presented as mean ± SEM, unless otherwise stated
^aCOPD severity was graded into GOLD I, Mild (FEV₁ ≥ 80 % predicted); GOLD II, Moderate (50 % ≤ FEV₁ < 80 % predicted); GOLD III, Severe (30 % ≤ FEV₁ < 50 % predicted); and GOLD IV, Very severe (FEV₁ < 30 % predicted) following the GOLD
FEV ₁ forced expiratory volume in 1 s, FVC forced vital capacity, PaO ₂ arterial partial oxygen pressure, PaCO ₂ arterial partial carbon dioxide pressure, CRP C reactive protein, COPD chronic obstructive pulmonary disease, GOLD Global Initiative for Chronic Obstructive Lung Disease, ICS inhaled corticosteroid, LABA long-acting β agonist, SABA short-acting β agonist, SAMA short-acting muscarinic agonist, N/D not done, N/A not applicable

ISSN: 1465-993X