Characteristics of quantitative arousal intensity and its association with cognitive function and sleepiness in sleep apnea patients

Xiang Gao; Yunhan Shi; Rongcui Sui; Shenglong Xu; Mengyu Xu; Jianhong Liao; Yanru Li; Demin Han

doi:10.1016/j.sleep.2025.106642

Characteristics of quantitative arousal intensity and its association with cognitive function and sleepiness in sleep apnea patients

Sleep Med. 2025 Jun 17:133:106642. doi: 10.1016/j.sleep.2025.106642. Online ahead of print.

Authors

Xiang Gao¹, Yunhan Shi¹, Rongcui Sui², Shenglong Xu¹, Mengyu Xu¹, Jianhong Liao¹, Yanru Li³, Demin Han⁴

Affiliations

¹ Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, PR China; Key Laboratory of Otorhinolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, PR China; Obstructive Sleep Apnea-Hypopnea Syndrome Clinical Diagnosis and Therapy and Research Centre, Capital Medical University, Beijing, PR China.
² Department of Otolaryngology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, PR China.
³ Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, PR China; Key Laboratory of Otorhinolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, PR China; Obstructive Sleep Apnea-Hypopnea Syndrome Clinical Diagnosis and Therapy and Research Centre, Capital Medical University, Beijing, PR China; Xinjiang Key Laboratory of Biopharmaceuticals and Medical Devices, Xinjiang Medical University, Urumqi, 830054, PR China. Electronic address: liyanruru@aliyun.com.
⁴ Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, PR China; Key Laboratory of Otorhinolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, PR China; Obstructive Sleep Apnea-Hypopnea Syndrome Clinical Diagnosis and Therapy and Research Centre, Capital Medical University, Beijing, PR China; Xinjiang Key Laboratory of Biopharmaceuticals and Medical Devices, Xinjiang Medical University, Urumqi, 830054, PR China. Electronic address: deminhan_ent@hotmail.com.

PMID: 40578293
DOI: 10.1016/j.sleep.2025.106642

Abstract

Study objectives: Obstructive sleep apnea (OSA) disrupts sleep, leading to cognitive impairment and sleepiness, but risk stratification remains unclear. We developed an EEG-based arousal marker to quantify sleep fragmentation and assessed its associations with neurocognitive function and daytime sleepiness.

Methods: Arousal intensity was derived from EEG signals in 1070 APPLES (Apnea Positive Pressure Long-term Efficacy Study) study participants. We analyzed its associations with PSG parameters, cognitive function (Wechsler Abbreviated Scale of Intelligence, WASI), and sleepiness (Multiple Sleep Latency Test, MSLT; Epworth Sleepiness Scale, ESS). Stepwise regression identified predictors of cognitive function. Sensitivity analysis examined arousal intensity's link to 6-month CPAP outcomes (N = 419).

Results: Among OSA individuals, the AHI ranged from 10 to 130.7/h, the average arousal index was 26.75/h and a total of 235,835 arousal events were extracted. The arousal intensity was significantly greater for hypoxia-associated and desaturation-related events compared to hypopnea-associated or spontaneous arousals (p<0.001). It correlated negatively with age, PSG measures, and cognitive function. Adjusted models showed Delta-band arousal intensity negatively predicted WASI-Full scores (β = -3.24, p = 0.019). Higher Gamma-band intensity was associated with both greater subjective sleepiness (ESS: β = 0.03, p = 0.028) and increased CPAP-induced MSLT improvement (β = 0.12, p = 0.020).

Conclusions: Arousal intensity is a novel EEG marker for cognitive impairment and sleepiness in OSA, with potential clinical utility in predicting CPAP response. This EEG-based marker could be integrated into standard sleep analysis platforms to identify OSA patients at risk of cognitive impairment, enabling early intervention.

Keywords: Arousal intensity; Cognitive function; OSA; Power spectrum analysis.