Symptom severity of obstructive sleep apnea (OSA) worsens significantly on the weekends and is likely associated with increased alcohol use and smoking, irregular sleep schedules, and lack of OSA treatment adherence, a new study showed. 

Individuals with at least mild OSA were 18% more likely to experience moderate-to-severe OSA on Saturdays compared with midweek. The effect, which investigators called “social apnea,” was especially pronounced in men and younger adults.

The findings offer “the first large-scale evidence that OSA severity increases on weekends,” lead author Lucía Pinilla, PhD, research fellow, Adelaide Institute for Sleep Health and FHMRI Sleep Health, Flinders University, Adelaide, Australia, and colleagues wrote.

The weekend spike could have health and safety consequences, they noted, adding that the findings hold implications for the therapeutic management of OSA. 

“Most clinical diagnostic testing is done on a single night, typically a weeknight, missing the weekend effect we’re now calling ‘social apnea,’” Pinilla said in a press release. “Sleep apnea is already a major public health issue, but our findings suggest its true impact may be underestimated.”

The study was published online on August 13 in American Journal of Respiratory and Critical Care Medicine. 

Weekend Effect

OSA, which affects an estimated one billion people worldwide, is characterized by repeated upper airway collapse during sleep. It raises risks for cardiovascular disease, diabetes, cognitive decline, depression, and accidents.

To study symptom severity over the course of multiple nights, investigators analyzed multinight data collected over 3 years (2020-2023) from more than 70,000 adult users of an FDA-validated under-the-mattress device intended to aid in the diagnosis of OSA at home. All participants had an apnea-hypopnea index (AHI) of at least five events per hour, meeting criteria for at least mild OSA.

Researchers found that odds of moderate-to-severe OSA (AHI ≥ 15/h) were 18% higher on Saturdays than on Wednesdays (odds ratio [OR], 1.18; 95% CI, 1.18-1.19).

The weekend effect was stronger in men than in women (OR, 1.21 vs OR, 1.09) and in those under 60 years than in older adults (OR, 1.24 vs OR, 1.07), consistent with higher alcohol and smoking behaviors in these groups.

Weekend “catch-up” sleep of 45 minutes or more was linked to a 47% higher risk for more severe OSA. Social jetlag, defined as a shift of at least 1 hour in sleep schedule, was associated with a 38% higher weekend risk.

On average, participants’ AHI was 6% higher on weekends, representing an increase of about 0.8 apnea events per hour across the cohort.

Limitations include reliance on consumer sensors, potential self-selection bias, and a sample skewed toward men. The study also lacked information on alcohol use, smoking, diet, comorbidities, and continuous positive airway pressure (CPAP) adherence.

Current Testing Missing the Mark?

Adherence to first-line OSA treatment with CPAP is typically defined as use on 70% of nights, which allows for lower use on weekends and could partly explain the increase in severity, researchers said.

However, they added, incorporating the potential for daily variations in OSA symptoms could enhance programs and therapies that encourage treatment adherence.

The findings also have implications for diagnostic testing. OSA diagnosis is typically based on a single-night sleep study, usually done on a weekday. But the new findings point to a significant variation in the night-to-night variability in OSA severity that “is currently not captured by gold-standard single-night sleep tests,” investigators noted.

“Obstructive sleep apnea severity can vary markedly between nights, which can yield inaccurate diagnoses in ~20% of patients and is an independent predictor of adverse cardiovascular outcomes,” researchers wrote.

Additional research is needed to better understand the biological underpinnings of the weekend pattern of worsening OSA severity. Whatever the mechanism may be, researchers said “ the observed increase in OSA severity on weekends may carry significant population-level societal costs, given the high prevalence and wide-ranging health and safety implications of OSA.” 

The study received no outside funding. Pinilla reported having no relevant disclosures. Full disclosures are available in the original article.