Table 2—

Mean systolic and diastolic blood pressure(SBP and DBP) and pulse interval (PI), and their variability (standard deviation) in the entire group (n = 18)

Sleep stageNocturnal wakefulnessNREM stage 2REM
Mean SBP mmHg
 No treatment132.5±13.3133.1±13.6143.4±18.9
 Acute CPAP134.3±18.3127.8±19.2134.2±20.8
 p-valuensnsns
sd of SBP mmHg
 No treatment11.2±4.0#15.3±3.514.7±3.4
 Acute CPAP7.8±1.1#5.7±1.35.9±1.2
 p-valuens<0.0001<0.0001
Mean DBP mmHg
 No treatment77.8±9.074.7±8.981.2±10.4
 Acute CPAP78.3±9.875.7±9.877.6±10.7
 p-valuensnsns
sd of DBP mmHg
 No treatment6.7±2.09.0±2.09.5±2.4
 Acute CPAP4.6±0.9#3.3±0.73.5±0.9
 p-value<0.05<0.0001<0.0001
Mean PI ms
 No treatment769±99840±102871±99
 Acute CPAP846±124862±133851±136
 p-valuensnsns
sd of PI ms
 No treatment56±19#88±32117±62
 Acute CPAP52±1836±1437±16
 p-valuens<0.0001<0.0001
  • The p-values refer to paired t-test applied to no treatment and acute continuous positive airway pressure (CPAP) data in each column. NREM: nonrapid eye movement; REM: rapid eye movement. #: wakefulness significantly different from NREM stage 2 and REM sleep (ANOVA to test differences among sleep stages); : wakefulness significantly different from REM sleep; p-value <0.05 in all comparisons.