Background To study the prevalence of symptoms of obstructive sleep apnoea (OSA) in a large, French, middle-aged population and to establish the proportion of these subjects with a combination of several symptoms warranting further investigation in a sleep study.

Methods We carried out a cross-sectional study on 2,195 males and 2,247 females, aged 33 to 69 (D.E.S.I.R. Cohort), recording their responses to a self-administered “sleep” questionnaire and a general questionnaire giving details on their lifestyle and socio-economic characteristics.

Results The following prevalence of symptoms was found in males and females respectively: frequent snoring (28%, 14%), frequent daytime sleepiness (14%, 18%) and frequent apnoeas (5%, 2%). 8.5% of males and 6.3% of females reported symptoms that were highly suggestive of OSA, (habitual snoring, daytime sleepiness and/or apnoeas). For both sexes this pattern of symptoms was associated with age and body mass index; after adjustment for these two factors it was associated with a poor self-reported health status and treatment with benzodiazepines or other sedatives. For males only, the OSA pattern of symptoms was also associated with, hypertension, alcohol consumption and smoking.

Conclusions Snoring, daytime sleepiness and witnessed apnoeas are symptoms frequently observed in the general population. In our study, 7.5% of the population have a combination of these abnormalities suggesting a high probability of obstructive sleep apnoea and therefore warrant a sleep study.