The epidemiology of sleep apnoea

We conducted a study of the prevalence of sleep-disordered breathing in subjects derived from a random sample of the population. A total of 2,202 subjects 35 to 69 yr of age were approached. Four hundred forty-one answered a questionnaire concerning their sleep symptoms, general health, and habits such as alcohol consumption, and they were monitored for sleep-disordered breathing (SDB). The sample was biased in favor of snorers and those with other subjective sleep complaints. Fifty-six percent of the subjects were men. Of the 441 subjects 79 (17.9%) had SDB (more than 15 episodes of apnea or hypopnea per hour: respiratory distress index [RDI] greater than or equal to 15), 289 were snorers but had RDI <15, and 73 were nonsnorers. The prevalence of SDB in this sample was therefore at least 3.6% (79 of 2,204). The minimum prevalence in men was 5.7%, and in women it was 1.2%. Logistic regression identified only male sex as an independent predictor of snoring without SDB (adjusted odds ratio [OR], 3.24; 95% Cl, 1.33 to 7.82), body mass index (adjusted OR for an increase of 5 kg/m(2), 0.95; 95% Cl, 0.85 to 1.05), and alcohol consumption (adjusted OR for an increase of 10 g/day, 1.05; 95% Cl, 0.84 to 1.37) were not significant predictors of snoring. The independent predictors of SDB among snorers were age (adjusted OR for an increase of 5 yr, 1.26; 95% Cl, 1.08 to 1.47) and neck circumference (adjusted OR for an increase of 2 cm, 1.53; 95% Cl, 1.16 to 2.00). Alcohol consumption was not a factor (adjusted OR for an increase of 10 g/day 0.98; 95% Cl, 0.86 to 1.12).