Table 2.

Polysomnographic data (N = 44)

	All Patients (N = 44)	COPD and OSA (n = 29)	COPD no OSA (n = 15)	P Value
Sleep efficiency, %	80.8 ± 14.2	80.2 ± 15.8	81.9 ± 10.8	0.71
N1, %	22.5 ± 15.0	25.8 ± 16.8	16.0 ± 7.4	0.04
N2, %	58.5 ± 13.6	55.9 ± 14.1	63.5 ± 11.4	0.08
N3, %	7.1 ± 8.7	7.4 ± 8.1	6.6 ± 10.0	0.77
REM, %	11.9 ± 7.8	10.9 ± 7.8	13.8 ± 7.8	0.24
Arousal index, events/h	29.4 ± 17.3	34.5 ± 17.9	19.4 ± 10.5	0.004
AHI, events/h	18.3 ± 20.8	26.4 ± 21.5	2.5 ± 1.4	<0.001

Definition of abbreviations: AHI = apnea–hypopnea index; COPD = chronic obstructive pulmonary disease; N1–N3 = sleep stages; OSA = obstructive sleep apnea; REM = rapid eye movement.

Data are presented as mean ± SD.