Journal of Otolaryngology and Ophthalmology of Shandong University ›› 2026, Vol. 40 ›› Issue (3): 68-73.doi: 10.6040/j.issn.1673-3770.0.2025.266

• Original Article • Previous Articles     Next Articles

Effects of continuous positive airway pressure on olfactory and cognitive functions in patients with moderate-to-severe obstructive sleep apnea-hypopnea syndrome

ZHAO Chunrong, YANG Sen, LI Chunyan, WANG Donghai, YANG Yu, YANG Xiaoying   

  1. Department of Otorhinolaryngology, Suining Central Hospital, Suining 629000, Sichuan, China
  • Published:2026-05-22

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2

Abstract: Objective To longitudinally evaluate the effects of continuous positive airway pressure(CPAP)on olfactory and cognitive functions in patients with moderate-to-severe obstructive sleep apnea-hypopnea syndrome(OSAHS). Methods Ninety patients with moderate-to-severe OSAHS received standardized CPAP therapy for 6 months. Olfactory function, including threshold, discrimination, identification, and the total threshold-discrimination-identification(TDI)score, was assessed using the Sniffin' Sticks test at baseline, 3 months, and 6 months. Cognitive function was evaluated with the Montreal Cognitive Assessment(MoCA)at the same time points. Pearson correlation analysis was used to assess the relationships between baseline apnea-hypopnea index(AHI)and improvements(Δ)in olfactory and cognitive functions, as well as the correlation between olfactory and cognitive improvements. Results After treatment, the total olfactory score increased from 19.81±2.88 to 26.49±2.56(P<0.05), and the total MoCA score increased from 19.52±2.48 to 22.58±1.87(P<0.05). Olfactory subdomains showed differential recovery trajectories: threshold and identification improved significantly at 3 months(P<0.05), while discrimination improved only at 6 months(P<0.05). Among cognitive subdomains, visuospatial/executive function, attention, and memory showed significant improvement at 3 months(P<0.05). Improvement in olfactory threshold was positively correlated with baseline AHI(r=0.41, P<0.05), and improvement in total olfactory score was positively correlated with improvement in total cognitive score(r=0.46, P<0.05). Subgroup analysis revealed that non-obese patients, those aged ≤50 years, and females exhibited greater olfactory improvement(P<0.05). Conclusion CPAP therapy effectively improves olfactory and cognitive functions in patients with moderate to severe OSAHS, with functional recovery demonstrating temporal differences and population heterogeneity. Olfactory improvement is positively correlated with cognitive improvement.

Key words: Sleep apnea, Obstructive, Olfactory function, Cognitive function, Continuous positive airway pressure

CLC Number: 

  • R749
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