Daytime sleepiness and its determining factors in Chinese obstructive sleep apnea patients

• Published in: Sleep & breathing Vol. 15; no. 1; pp. 129 - 135
• Main Authors: Chen, Rui, Xiong, Kang-ping, Lian, Yi-xin, Huang, Juan-ying, Zhao, Min-yan, Li, Jian-xiang, Liu, Chun-feng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2011; Springer; Springer Nature B.V
• Subjects: Adult; Arousal; Biological and medical sciences; Body Mass Index; China; Cohort Studies; Cross-Cultural Comparison; Cross-Sectional Studies; Dentistry; Disorders of Excessive Somnolence - diagnosis; Disorders of Excessive Somnolence - epidemiology; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Female; Fundamental and applied biological sciences. Psychology; Health Surveys; Humans; Internal Medicine; Male; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; Multiple sclerosis and variants. Guillain barré syndrome and other inflammatory polyneuropathies. Leukoencephalitis; Nervous system (semeiology, syndromes); Neurology; Original Article; Otorhinolaryngology; Oxygen - blood; Patients; Pediatrics; Pneumology/Respiratory System; Polysomnography; Sleep apnea; Sleep Apnea, Obstructive - diagnosis; Sleep Apnea, Obstructive - epidemiology; Sleep disorders; Sleep Stages; Sleep. Vigilance; Snoring - physiopathology; Statistics as Topic; Surveys and Questionnaires; Vertebrates: nervous system and sense organs; China; Excessive daytime sleepiness; Polysomnography; Nocturnal hypoxemia; Obstructive sleep apnea–hypopnea syndrome; Human; Oxygen; Nervous system diseases; Sleep apnea syndrome; Obstructive sleep apnea-hypopnea syndrome; Respiratory disease; Sleep disorder; Hypoxemia; Sleep; Chinese; Sleep wake cycle; Neurological disorder
• ISSN: 1520-9512; 1522-1709
• DOI: 10.1007/s11325-010-0337-4

Objective The aim of this study was to characterize excessive daytime sleepiness (EDS) in a large cohort of Chinese patients with various severity of obstructive sleep apnea–hypopnea syndrome (OSAHS), and investigate its correlations with clinical/polysomnographic variables. Materials and methods A total of 1,035 consecutive Chinese patients with snoring (mean age ± SD 45 ± 15 years, BMI 26.6 ± 4.3 kg/m 2 ) were examined by overnight polysomnography, and subjective EDS was assessed using the Epworth Sleepiness Scale (ESS). Results The 1,035 patients were compared according to severity of sleep-disordered breathing: AHI <5 (primary snoring group or normal overall AHI) (24.1%), AHI 5–20 (mild OSAHS, 21.7%), AHI >20–40 (moderate OSAHS 16.5%), and AHI >40 (severe OSAHS 37.7%). ESS score progressively increased as the severity of OSAHS aggravated among these patients. More severe OSAHS patients were characterized by EDS, nocturnal hypoxemia, and disruption of sleep structure. Progressive worsening of nocturnal hypoxemia was observed from mild to severe OSAHS patients with a strong correlation with ESS score. The stepwise multiple regression analysis performed to evaluate the correlations of individual clinical and polysomnographic variables with the ESS score revealed that the ESS score significantly correlated with the oxygen desaturation index (ODI), apnea–hypopnea index (AHI), and body mass index (BMI), and ODI was the strongest determinant of ESS score. Conclusion EDS is correlated with the severity of OSAHS. More severe patients are characterized by higher ESS score, higher BMI, and progressive worsening of nocturnal hypoxemia. Nocturnal hypoxemia is a major determinant of EDS in Chinese OSAHS patients.