Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study

Background Sleep-disordered breathing is associated with major morbidity and mortality. However, its prevalence has mainly been selectively studied in populations at risk for sleep-disordered breathing or cardiovascular diseases. Taking into account improvements in recording techniques and new criteria used to define respiratory events, we aimed to assess the prevalence of sleep-disordered breathing and associated clinical features in a large population-based sample. Methods Between Sept 1, 2009, and June 30, 2013, we did a population-based study (HypnoLaus) in Lausanne, Switzerland. We invited a cohort of 3043 consecutive participants of the CoLaus/PsyCoLaus study to take part. Polysomnography data from 2121 people were included in the final analysis. 1024 (48%) participants were men, with a median age of 57 years (IQR 49-68, range 40-85) and mean body-mass index (BMI) of 25.6 kg/m(2) (SD 4.1). Participants underwent complete polysomnographic recordings at home and had extensive phenotyping for diabetes, hypertension, metabolic syndrome, and depression. The primary outcome was prevalence of sleep-disordered breathing, assessed by the apnoea-hypopnoea index. Findings The median apnoea-hypopnoea index was 6-9 events per h (IQR 2.7-14.1) in women and 14.9 per h (7.2-27.1) in men. The prevalence of moderate-to-severe sleep-disordered breathing (>= 15 events per h) was 23.4% (95% CI 20.9-26.0) in women and 49.7% (46.6-52.8) in men. After multivariable adjustment, the upper quartile for the apnoea-hypopnoea index (>20.6 events per h) was associated independently with the presence of hypertension (odds ratio 1.60, 95% CI 1.14-2.26; p=0.0292 for trend across severity quartiles), diabetes (2.00, 1.05-3.99; p=0.0467), metabolic syndrome (2.80, 1.86-4.29; p<0.0001), and depression (1.92, 1.01-3.64; p=0.0292). Interpretation The high prevalence of sleep-disordered breathing recorded in our population-based sample might be attributable to the increased sensitivity of current recording techniques and scoring criteria. These results suggest that sleep-disordered breathing is highly prevalent, with important public health outcomes, and that the definition of the disorder should be revised.