Table 1—

Anthropometric and sleep data

No treatmentAcute CPAP OSA all
OSA smokersOSA nonsmokersOSA all
Patients n1081818
Age yrs42.7±7.145.0±10.543.7±8.6
Body mass index kg·m−236.8±4.633.7±7.635.5±6.1
Office systolic BP mmHg135.0±8.7127.5±11.3131.5±10.4
Office diastolic BP mmHg87.7±5.780.0±7.1#84.1±7.3
Apnoea/hypopnoea index n·h−181±1278±2780±204±3
BP recording time min272±59280±48275±53157±50
Nocturnal wakefulness % of BP recording time+17.0±9.912.3±5.814.9±8.512.7±16.0
NREM stage 2 sleep % of BP recording time+62.6±10.867.8±13.064.9±11.851.2±18.1
NREM stage 3–4 sleep % of BP recording time+0.9±2.74.2±7.42.4±5.413.9±15.0
REM sleep % of BP recording time+8.2±4.58.6±4.78.4±4.420.1±14.3
Sa,O2 during wakefulness %95.3±1.396.0±1.395.7±1.396.2±1.4
Mean lowest Sa,O2 NREM sleep %76.7±6.984.9±4.4#80.2±7.395.8±1.4
Mean lowest Sa,O2 REM sleep %60.6±11.271.5±12.964.9±13.095.3±1.6
  • BP: blood pressure; CPAP: continuous positive airway pressure; OSA: obstructive sleep apnoea; REM: rapid eye movement; NREM: nonrapid eye movement; Sa,O2: arterial oxygen saturation. +: sum of % BP recorded time is <100 because NREM stage 1 sleep is not reported (see Methods); #: p<0.05 versus smokers (unpaired t-test); : p<0.05 between baseline and acute CPAP application (paired t-test).