O041 Obstructive sleep apnoea worsens on weekends with irregular sleep patterns

Abstract Introduction Obstructive sleep apnoea (OSA) severity can vary markedly between nights, which may yield inaccurate diagnoses and is an independent predictor of poor health outcomes (e.g., hypertension). This study evaluates day-of-week variations in OSA severity and relationships with weekly changes in sleep duration and timing. Methods Multi-night data (January 2020-September 2023) were acquired from regular users of a validated under-the-mattress OSA monitor who showed an average apnoea-hypopnoea index (AHI) ≥5 events/hr. Non-linear logistic fixed effect models assessed the association between night of the week and the odds of OSA (AHI ≥ 15 events/hr). Results The study included 70 052 participants from 23 countries (81% male; mean ± SD age 53 ± 13 years; BMI 29 ± 6 kg/m2, AHI 18 ± 14 events/hr). OSA severity significantly increased on weekends. The likelihood (OR [95%CI]) of OSA was 18% (1.18 [1.18 to 1.19]) higher on weekends compared to weekdays. This effect was ~2-fold greater in men vs. women, ~4-fold greater in younger (<60 y/o) vs. older (≥60 y/o) participants, and ~ 3-fold greater in shorter (<7hr) vs. longer (≥8hr) sleepers. Weekend catch-up sleep (weekend vs. weekday difference in sleep duration) ≥45 min (Q4) and social jetlag (weekend vs. weekday difference in sleep midpoint) ≥60 min (Q4) were associated with a further ~55% increase in the weekend odds of OSA. Conclusions These novel findings indicate a global increase in OSA severity on weekends, particularly in people with irregular weekly sleep patterns. The “social apnoea” phenomenon is likely to carry significant population-level societal costs, given the high prevalence and wide-ranging health and safety implications of OSA.