The HypnoLaus study aimed to assess the prevalence of sleep-disordered breathing (SDB) and its associated clinical features in a large, population-based sample using modern polysomnographic techniques and updated scoring criteria. Between September 1, 2009, and June 30, 2013, 2121 participants from the CoLaus/PsyCoLaus study cohort underwent polysomnography at home. The median apnea-hypopnea index was 6-9 events per hour in women and 14-9 events per hour in men. The prevalence of moderate-to-severe SDB (≥5 events per hour) was 23-4% in women and 49-7% in men. After multivariable adjustment, the upper quartile of the apnea-hypopnea index (>20.6 events per hour) was independently associated with hypertension, diabetes, metabolic syndrome, and depression. These findings suggest that SDB is highly prevalent and that the definition of the disorder should be revised to reflect its severity spectrum. The study highlights the importance of identifying individuals at high risk of complications due to SDB and emphasizes the need for a comprehensive clinical approach to treatment.The HypnoLaus study aimed to assess the prevalence of sleep-disordered breathing (SDB) and its associated clinical features in a large, population-based sample using modern polysomnographic techniques and updated scoring criteria. Between September 1, 2009, and June 30, 2013, 2121 participants from the CoLaus/PsyCoLaus study cohort underwent polysomnography at home. The median apnea-hypopnea index was 6-9 events per hour in women and 14-9 events per hour in men. The prevalence of moderate-to-severe SDB (≥5 events per hour) was 23-4% in women and 49-7% in men. After multivariable adjustment, the upper quartile of the apnea-hypopnea index (>20.6 events per hour) was independently associated with hypertension, diabetes, metabolic syndrome, and depression. These findings suggest that SDB is highly prevalent and that the definition of the disorder should be revised to reflect its severity spectrum. The study highlights the importance of identifying individuals at high risk of complications due to SDB and emphasizes the need for a comprehensive clinical approach to treatment.