30-Second Takeaway
- Chronic daily cannabis use is linked with objectively worse sleep continuity on PSG in sleep-clinic patients.
- Long COVID remains associated with short, poor-quality, and disturbed sleep for up to three years post-infection.
- OSA-related hypoxemia and reduced spindles jointly predict earlier dementia, suggesting a potentially modifiable pathway.
Week ending December 20, 2025
Cannabis, Long COVID, OSA, and AI tools: updating sleep medicine practice
Chronic daily cannabis use is associated with poorer PSG sleep continuity
In a retrospective sleep-clinic cohort of 1,449 adults, 151 long-term daily cannabis users were compared with 1,298 never-users on PSG metrics. Chronic cannabis use was associated with higher wake after sleep onset and lower sleep efficiency after extensive covariate adjustment. Users also spent a greater percentage of sleep in N1, and total sleep time was nominally lower. Effects persisted across sensitivity analyses, but most participants had moderate-to-severe sleep apnea, limiting generalizability.
Long COVID predicts shorter, poorer sleep up to three years later
A population-based Michigan cohort of 2,406 adults with COVID-19 examined longitudinal associations between Long COVID and sleep outcomes. Long COVID, defined as recovery time ≥90 days, was associated with 0.35 hours shorter sleep at ~1.5-year follow-up. Relative to 6–9 hours, Long COVID increased the risk of sleeping <6 hours at both ~1.5 and ~3 years post-infection. Long COVID was also associated with poor-to-very poor sleep quality and a 1.53-fold higher risk of moderate-to-severe sleep disturbance.
NREM oxygenation, sleep spindles, and dementia risk appear mechanistically linked
This mediation analysis in 2,023 SHHS participants linked NREM oxygenation, sleep spindles, and adjudicated dementia over a median 21-year follow-up. Lower NREM SpO2 and higher hypoxic burden predicted earlier dementia, with spindle density significantly mediating both associations. Better NREM SpO2 and lower hypoxic burden were associated with increased spindle density and modest delays in dementia diagnosis. Spindle density mediated roughly one-quarter of the NREM SpO2 effect and most of the hypoxic-burden effect on time-to-dementia.
CPAP reduces nocturnal arrhythmia avalanche burden in an adherence-dependent manner
A secondary analysis of the HeartBEAT randomized trial assessed nocturnal arrhythmia avalanches in 245 adults with moderate OSA. Compared with control and nocturnal supplemental oxygen, CPAP reduced nocturnal arrhythmia avalanche burden by about 40%, while other groups showed no significant change. Each additional day of CPAP use ≥4 hours per night was linked with a 14% reduction in arrhythmia avalanches, demonstrating a dose–response relationship. High BMI and smoking significantly attenuated CPAP’s anti-arrhythmic effect.
References
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Additional Reads
Optional additional studies from this edition.