More than 80 percent of patients with long COVID have obstructive sleep apnoea (OSA), and these patients present with insomnia rather than the classic excessive daytime sleepiness, according to new research.
In a Spanish cohort of long COVID patients (mean time since the acute COVID episode, 1.8 years), OSA (apnoea-hypopnea index [AHI] ≥5/h) was present in 83.6 percent of participants, including postural OSA in 60.3 percent and positional OSA in 19.2 percent. [Respir Med 2026;doi:10.1016/j.rmed.2026.108848]
The median AHI was 17.2 events/h. OSA was severe in 31.5 percent of participants, moderate in 24.6 percent, and mild in 27.4 percent.
Symptoms were assessed two ways: objectively and subjectively, using validated questionnaires and through self-report, respectively. Poor sleep quality and fatigue were the most prevalent objectively assessed symptoms, while daytime sleepiness was the least prevalent. Among self-reported symptoms, insomnia was the most common, followed by dyspnoea and fatigue.
Insomnia was the only symptom associated with OSA (p=0.014). Insomnia Severity Index (ISI) scores (≥14) were especially high among 56.7 percent of long COVID patients with concomitant relevant OSA (AHI ≥15 events/h) as opposed to only 36.6 percent of those with no-relevant OSA (AHI <15 events/h).
In logistic regression analyses, high ISI scores were associated with 7-percent increased odds of AHI ≥15 events/h (odds ratio [OR], 1.07, 95 percent confidence interval [CI], 1.03–1.11; p=0.05). This association persisted after adjustment for age, BMI, and hospitalization (aOR, 1.08, 95 percent CI, 1.04–1.12).
“This study presents the largest cohort of long COVID patients with well-characterized OSA diagnosis that agreed to undergo polysomnography and validated questionnaires, assessed nearly 2 years after an acute COVID event of varying severity,” the authors noted.
“The prevalence of excessive daytime sleepiness, measured by the Epworth Sleepiness Scale, one of the most recognized symptoms of OSA, was similarly low across OSA severity groups. Conversely, insomnia, determined by an ISI score ≥14 (cutoff for moderate to severe insomnia), was the only symptom associated with AHI,” they added.
While requiring validation, the findings suggest that diagnostic evaluation for OSA may be considered in long COVID patients even in the absence of classic OSA symptoms or in the presence of insomnia, according to the authors. This is important, they added, given that “OSA is a treatable condition.”
The study included 73 patients with long COVID (mean age 57.4 years, 56.2 percent male, mean BMI 29.9 kg/m2), of whom 73.9 percent were hospitalized during the acute COVID episode. More than a third (35.6 percent) were former smokers, and 78 percent had at least one comorbidity. Hypertension and dyslipidaemia were the most frequent comorbidities.
“Further studies are needed to determine whether OSA treatment improves long COVID-related outcomes,” the authors said.