The unique alterations of hippocampus and cognitive impairment in chronic obstructive pulmonary disease

Respiratory Research

Table 1 Demographic characteristics in the control group and mild-to-moderate and severe COPD groups

Characteristic	Control group (n = 31)	Mild-to-moderate COPD group (n = 37)	Severe COPD group (n = 48)	P Value
Age, years	66.48 ± 6.96	69.27 ± 8.08	67.60 ± 7.63	0.31^a
Females/males, n	10/21	9/28	13/35	0.76^b
Smoking status, %				0.91^b
Never smoked	41.93	35.14	45.83
Current smoker	25.81	29.73	25.00
Ex-smoker	32.26	35.13	29.17
Cigarettes smoked, pack-years
Current smoker	34.13 ± 12.11	33.09 ± 8.11	34.13 ± 5.52	0.95^a
Ex-smoker	27.25 ± 8.68	29.00 ± 6.60	32.64 ± 7.81	0.22^a
Education, years	8.07 ± 4.97	9.49 ± 4.75	9.42 ± 4.01	0.35^a
BMI, kg/m²	22.51 ± 2.67	22.11 ± 3.66	21.91 ± 3.29	0.73^a
Cardiovascular disease, %	38.71	54.05	54.17	0.34^b

Data are presented as means ± SD, except where indicated otherwise. Cardiovascular diseases include hypertension, coronary artery disease and congestive heart failure. BMI = Body Mass Index.
^a: One-way analysis of variance. ^b: Analysis of Chi-Square test.

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