Patterns of brain structural alteration in COPD with different levels of pulmonary function impairment and its association with cognitive deficits

Table 1 Demographic and clinical characteristics of the participants

Variables	Comparison group (n = 31)	Mild COPD (n = 29)	Moderate COPD (n = 29)	Severe COPD (n = 26)	F/χ² value	P value
Age	57.12 ± 8.66	59.38 ± 8.27	60.90 ± 10.63	63.42 ± 9.53	1.91	0.13^a
Sex (M/F)	(22/9)	(14/15)	(13/16)	(18/8)	6.69	0.08^b
Education level (year)	9.06 ± 2.13	9.28 ± 2.03	9.34 ± 1.97	9.19 ± 2.23	1.00	0.96^a
BMI (kg/m²)	24.17 ± 2.93	24.08 ± 4.50	23.19 ± 4.27	22.19 ± 3.27	1.64	0.19^a
Current smoking status (Y/N)	(17/14)	(11/18)	(14/15)	(16/10)	3.39	0.34^b
Smoking index (packs/year)	22.26 ± 1.12	22.69 ± 1.42	23.03 ± 1.32	23.35 ± 2.54	2.28	0.08^a
FEV₁%	105.34 ± 21.61	85.18 ± 4.21*	65.93 ± 8.19**	38.16 ± 7.63***	143.51	0.000^a
PaO₂ (mmHg)	116.76 ± 6.64	99.75 ± 7.88*	77.18 ± 4.94**	66.50 ± 3.92***	393.71	0.000^a
NormalPaO₂, n(%)	31 (100)	29 (100)	9 (31.0)	0 (0)	89.14	0.000^b
SaO₂%	98.14 ± 0.43	96.23 ± 0.60*	94.56 ± 0.83**	91.67 ± 1.15***	342.28	0.000^a
Normal SaO₂, n(%)	31 (100)	29 (100)	21 (72.4)	0 (0)	87.18	0.000^b
WMH score	1.64 ± 0.97	1.73 ± 0.81	1.69 ± 1.12	1.85 ± 1.09	1.13	0.94^a

Note: Data are presented as the means ± standard deviations, except where otherwise indicated. Abbreviations: a, analysis of variance; b, χ² test; BMI, body mass index; F, female; FEV1, forced expiratory volume in 1 s; M, male; N, no; PaO₂, arterial partial pressure of oxygen; SaO₂, oxygen saturation; WMH, white matter hyperintensity; and Y, yes. *Significantly different from controls (P < 0.001). **Significantly different from patients with mild COPD (P < 0.001). ***Significantly different from patients with moderate COPD (P < 0.001)

ISSN: 1471-2466