Table 1.

Baseline characteristics of all patients (n = 51)

Variable	Overall (n = 51)	OSA (n = 29)	No OSA (n = 22)	P Value*
Sex, female/male	33/18	17/12	16/6	0.38
Age, yr	59 ± 9	56 ± 8	62 ± 9	0.01
BMI,† kg/m2	32 ± 9	35 ± 9	29 ± 7	0.007
Pack-years‡	43 ± 24	42 ± 28	45 ± 19	0.37
BODE index	3.0 ± 1.7	3.4 ± 1.8	2.5 ± 1.4	0.04
FEV1, % predicted, L	1.4 ± 0.5 (57 ± 21)	1.4 ± 0.6 (54 ± 24)	1.5 ± 0.5 (63 ± 17)	0.61
FVC, % predicted, L	2.4 ± 0.7 (76 ± 18)	2.4 ± 0.7 (71 ± 19)	2.6 ± 0.8 (83 ± 13)	0.52
FEV1/FVC, %	58 ± 14	58 ± 16	58 ± 12	0.91
CT-derived percent emphysema†	11.1 ± 13.1	10.2 ± 14.1	12.3 ± 12.1	0.11
CT-derived percent gas trapping†	31.6 ± 24.1	28.1 ± 26.3	35.6 ± 21.4	0.11
AHI, events/h	11 ± 12	18 ± 12	2 ± 1	<0.0001
Non–REM AHI, events/h	9 ± 14	15 ± 16	2 ± 2	<0.0001
REM AHI, events/h	22 ± 25	33 ± 26	4 ± 7	0.0001
TST, min	296 ± 74	293 ± 83	299 ± 62	0.95
Sleep efficiency, %	72 ± 19	69 ± 22	76 ± 14	0.28
Arousal index, events/h	20 ± 19	25 ± 23	15 ± 11	0.04
Mean SaO2, %	93 ± 3	93 ± 3	94 ± 3	0.17
Lowest SaO2, %	83 ± 8	81 ± 7	85 ± 8	0.02
Percent TST SaO2 <90%	13 ± 23	15 ± 25	10 ± 21	0.10
Sleep architecture, % TST
Stage N1	13.5 ± 8.7	12.8 ± 7.5	14.3 ± 10.2	0.82
Stage N2	61.5 ± 14.1	62.5 ± 13.4	60.2 ± 15.1	0.68
Stage N3	7.7 ± 9.7	8.7 ± 11.1	6.4 ± 7.6	0.37
Stage REM	17.4 ± 8.9	16.0 ± 8.7	19.2 ± 8.9	0.35

Definition of abbreviations: AHI = apnea–hypopnea index; BMI = body mass index; BODE = body mass index, airflow obstruction, dyspnea, and exercise capacity; CT = computed tomography; OSA = obstructive sleep apnea; REM = rapid eye movement; TST = total sleep time.

Data are presented as the mean ± SD unless otherwise indicated.

^*Based on Fisher’s exact test or Wilcoxon rank-sum test.

^†Missing values for BMI, CT-derived percent emphysema, and CT-derived percent gas trapping for the OSA/no OSA groups: 1/0, 5/4, and 10/5, respectively.

^‡According to American Thoracic Society guidelines.