Long-term CPAP treatment partially improves the link between cardiac vagal influence and delta sleep

BMC Pulmonary Medicine

Table 2 Sleep parameters for the entire night and the first three sleep cycles

	SAHS patients	SAHS patients	Healthy controls
	before CPAP	with CPAP
Parameters for entire night
TIB (min)	470 ± 36	471 ± 44	466 ± 56
SPT (min)	444 ± 56	446 ± 58	444 ± 64
TST (min)	397 ± 48	401 ± 55	414 ± 61
Sleep efficiency (%)	84 ± 8	85 ± 8	87 ± 5
Sleep latency (min)	19 ± 9	23 ± 9	16 ± 10
Amount of nocturnal awakenings	74 ± 56	38 ± 14	38 ± 16
Amount of sleep changes	231 ± 99	167 ± 57	218 ± 81
NREM duration (min)	337 ± 35	309 ± 58	322 ± 47
REM duration (min)	63 ± 28*	89 ± 11	91 ± 24
WASO duration (min)	44 ± 30	48 ± 33	30 ± 18
NREM duration (% SPT)	76 ± 8	69 ± 8	73 ± 3
Deep sleep duration (% SPT)	3 ± 4	4 ± 7	7 ± 6
REM duration (% SPT)	14 ± 6**	20 ± 5	21 ± 4
WASO duration (% SPT)	10 ± 7	10 ± 6	7 ± 4
*Parameters for the first three NREM-REM cycles*
Sleep cycles duration (min)	331 ± 55	316 ± 60	296 ± 35
NREM duration (min)	253 ± 43	229 ± 55	221 ± 24
Light sleep duration (min)	237 ± 65*	216 ± 58	190 ± 30
Deep sleep duration (min)	16 ± 25	13 ± 20	31 ± 24
REM duration (min)	47 ± 25	63 ± 21	63 ± 19
WASO duration (min)	31 ± 24	25 ± 17	12 ± 6

SAHS, Sleep apnea-hypopnea syndrome; CPAP, Continuous positive airway pressure; TIB, Time in bed; SPT, Sleep period time; TST, Total sleep time; NREM, Non rapid eye movement sleep; REM, Rapid eye movement sleep; WASO, Wake after sleep onset; light sleep: sleep stages 1 + 2; deep sleep: sleep stages 3 + 4; min: minutes. Results were expressed as mean ± standard deviation. * P < 0,05, ** P < 0,01 vs. healthy controls.
Patients suffering from severe SAHS showed decreased overnight REM duration, expressed in minutes (min) or in percentage of the SPT (% SPT), and increased light sleep duration over the first three NREM-REM cycles, in comparison to healthy controls. All other sleep variables were similar between untreated apneic patients and controls as well as between CPAP treated apneic patients and controls.

ISSN: 1471-2466