Case-Control Study Shows Prior COVID-19 Linked Only to Heightened Post-Arousal Ventilatory Response in Sleep Apnea

Researchers at Koç University performed overnight polysomnography on 60 individuals with prior COVID-19 and 60 matched controls who had testing before the pandemic. Participants averaged 55 years old, BMI 29.4 kg/m², and were predominantly male; groups were balanced on apnea-hypopnea index. Physiological traits were derived from standard sleep recordings and adjusted for age, sex, BMI, and AHI. The design allowed direct comparison of four core mechanisms that determine obstructive sleep apnea severity without relying on self-report or surrogate markers.

No statistically significant group differences emerged for airway collapsibility, loop gain, arousal threshold, or dilator muscle responsiveness. The sole exception was a larger increase in ventilation immediately following brief arousals among the post-COVID group. Absolute differences were not quantified in the report, yet the direction was consistent after multivariable adjustment. This isolated change could theoretically influence sleep fragmentation or treatment response, though its magnitude and reproducibility remain unknown.

Earlier observational data had raised the possibility that COVID-19 might worsen sleep apnea through persistent respiratory or autonomic effects. The present null findings on most traits narrow that hypothesis while leaving open effects in unmeasured subgroups or via pathways such as inflammation not captured by standard trait estimation. The retrospective case-control structure precludes causal inference and cannot address incidence of new OSA after infection.

Prospective cohorts with serial polysomnography before and after documented infection are required to test whether the post-arousal response difference translates into measurable changes in apnea frequency or daytime symptoms over 12–24 months.