INFLUENCE OF MODERATE ALCOHOL-CONSUMPTION ON OBSTRUCTIVE SLEEP-APNEA WITH AND WITHOUT AUTOSET(TM) NASAL CPAP THERAPY

Snoring worsens with high alcohol consumption. It is unclear whether m oderate alcohol intake worsens sleep and breathing in subjects with ob structive sleep apnoea syndrome (OSAS), and whether alcohol increases the pressure requirement for nasal continuous positive airway pressure (CPAP). Fourteen adult males with untreated OSAS but without heart or lung disease were studied (age 53+/-9 yrs, body mass index (BMI) 33+/ -5 kg . m(-2) (mean+/-SD). The subjects underwent overnight polysomnog raphy on four occasions: control alcohol, CPAP, and alcohol + CPAP. On the alcohol nights, the subjects drank 1.5 mL . kg(-1) body weight (B W) vodka (40% alcohol by volume) (blood alcohol with and without CPAP 0.45+/-0.1 and 0.47+/-0.2 mg . mL(-1) (mean+/-SD)). On the CPAP nights , the pressure required to prevent apnoea, snoring, and silent inspira tory airflow limitation was determined using an autotitrating nasal CP AP system (ResCare AutoSet(TM)). Alcohol and control nights were perfo rmed in random order. Without CPAP, alcohol produced a small non-signi ficant decrease in the percentage of rapid eye movement (REM) sleep (c ontrol 11+/-2 vs alcohol 8+/-1% (mean+/-SEM)), but with CPAP there was no such effect (control 15+/-2 vs 17+/-2%; CPAPxalcohol interaction p =0.015). With CPAP, slow-wave sleep in the first 2 h increased slightl y with alcohol (control 39+/-6 vs alcohol 51+/-4%; p=0.004). Arousal i ndex without CPAP increased slightly with alcohol (control 43+/-5 vs a lcohol 49+/-6 events . h(-1); p=0.02). There was little or no effect o f alcohol on other sleep stages, arousal index, apnoea index, apnoea/h ypopnoea index, mean or longest event duration, mean or worst arterial oxygen saturation, with or without CPAP, either for the full night or for the first 2 h. There was no change in the pressure requirement fo r CPAP (full night: control 11.9+/-0.9 vs alcohol 12.5+/-0.9 cmH(2)O; first 2 h: 10.9+/-0.6 vs 11.1+/-0.8 cmH(2)O). Moderate alcohol intake (in the form of vodka) has little effect on breathing or saturation du ring sleep in subjects with mild-to-severe obstructive sleep apnoea, a nd no effect on the pressure required for continuous positive ah-way p ressure in order to prevent apnoea, snoring, and flow limitation. Thes e results cannot be extrapolated to other doses or forms of alcohol, o r to subjects with concurrent heart or lung disease.