Daytime sleepiness and polysomnographic variables in sleep apnoea patients

Excessive daytime sleepiness (EDS) is not invariably present in patients with obstructive sleep apnoea syndrome (OSAS). The aim of the present study was to investigate polysomnographic determinants of EDS in patients with OSAS. EDS was assessed using the Epworth Sleepiness Scale (ESS) and the multiple sleep latency test (MSLT). Patients showed EDS whenever the ESS score was >10 and the MSLT score <5 min. Absence of EDS was defined as having an ESS score of <10 and an MSLT score of >10 min. In total, 23 male patients with EDS (mean±sd ESS and MSLT score 17±3 and 4±1 min, respectively) and 17 without EDS (ESS and MSLT score 5±2 and 16±3 min, respectively), were studied. Both groups exhibited a similar apnoea/hypopnoea index (62±18 versus 60±20 events·h−1). Patients with EDS exhibited shorter sleep latency (11±16 versus 18±18 min) and greater sleep efficiency (90±7 versus 82±13%) than those without EDS. Patients with EDS showed lower oxygenation (lowest arterial oxygen saturation 69±12 versus 79±8%; mean arterial oxygen saturation 87±6 versus 90±5%). Sleep stage distribution and arousal index did not differ between the groups. Patients with obstructive sleep apnoea syndrome and excessive daytime sleepiness are characterised by shorter sleep latency, increased sleep efficiency and worse nocturnal oxygenation than those without excessive daytime sleepiness. Nocturnal hypoxaemia can be a major determinant of excessive daytime sleepiness in patients with obstructive sleep apnoea syndrome.

[1]  P. L. Smith,et al.  Modeling hypersomnolence in sleep-disordered breathing. A novel approach using survival analysis. , 1999, American journal of respiratory and critical care medicine.

[2]  C. Guilleminault,et al.  EEG arousals: scoring rules and examples: a preliminary report from the Sleep Disorders Atlas Task Force of the American Sleep Disorders Association. , 1992, Sleep.

[3]  Olli Polo,et al.  Pathogenesis of obstructive sleep apnoea/hypopnoea syndrome , 1994, The Lancet.

[4]  D. Praticò,et al.  Inducible nitric oxide synthase in long-term intermittent hypoxia: hypersomnolence and brain injury. , 2005, American journal of respiratory and critical care medicine.

[5]  Oguz Kokturk,et al.  Apnea-Hypopnea Indexes Calculated Using Different Hypopnea Definitions and Their Relation to Major Symptoms , 2004, Sleep and Breathing.

[6]  E. Chiner,et al.  [Validation of the Spanish version of the Epworth Sleepiness Scale in patients with a sleep apnea syndrome]. , 1999, Archivos de bronconeumologia.

[7]  D. Gozal,et al.  Sleep pressure correlates of cognitive and behavioral morbidity in snoring children. , 2004, Sleep.

[8]  E. Klann,et al.  NADPH oxidase mediates hypersomnolence and brain oxidative injury in a murine model of sleep apnea. , 2005, American journal of respiratory and critical care medicine.

[9]  D. Gozal,et al.  Sleepiness and neurodegeneration in sleep-disordered breathing: convergence of signaling cascades. , 2005, American journal of respiratory and critical care medicine.

[10]  H. Colt,et al.  Hypoxemia vs sleep fragmentation as cause of excessive daytime sleepiness in obstructive sleep apnea. , 1991, Chest.

[11]  M. Carskadon,et al.  Guidelines for the multiple sleep latency test (MSLT): a standard measure of sleepiness. , 1986, Sleep.

[12]  M. Johns.  Daytime sleepiness, snoring, and obstructive sleep apnea. The Epworth Sleepiness Scale. , 1993, Chest.

[13]  C. Guilleminault,et al.  Obstructive sleep apnea syndrome, sleepiness, and quality of life. , 2004, Chest.

[14]  A. Rechtschaffen,et al.  A manual of standardized terminology, technique and scoring system for sleep stages of human subjects , 1968 .

[15]  R. Chervin.  Epworth sleepiness scale? , 2003, Sleep medicine.

[16]  J. L. Harrison,et al.  The Government Printing Office , 1968, American Journal of Pharmaceutical Education.

[17]  Meir Kryger,et al.  Reducing motor-vehicle collisions, costs, and fatalities by treating obstructive sleep apnea syndrome. , 2004, Sleep.

[18]  C. Feuerstein,et al.  Cognitive executive dysfunction in patients with obstructive sleep apnea syndrome (OSAS) after CPAP treatment. , 1998, Sleep.

[19]  D. Praticò,et al.  Long-term intermittent hypoxia in mice: protracted hypersomnolence with oxidative injury to sleep-wake brain regions. , 2004, Sleep.

[20]  A. Agustí,et al.  Long-term effects of CPAP on daytime functioning in patients with sleep apnoea syndrome. , 2000, The European respiratory journal.

[21]  D. Gozal,et al.  Sleep pressure score: a new index of sleep disruption in snoring children. , 2004, Sleep.

[22]  E. Wolpert.  A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects. , 1969 .

[23]  R. Chervin,et al.  Electroencephalographic changes during respiratory cycles predict sleepiness in sleep apnea. , 2005, American journal of respiratory and critical care medicine.

[24]  W C Dement,et al.  Determinants of daytime sleepiness in obstructive sleep apnea. , 1988, Chest.

[25]  J. M. Arriero,et al.  Validación de la versión española del test de somnolencia Epworth en pacientes con síndrome de apnea de sueño , 1999 .

[26]  F. Richer,et al.  Nocturnal hypoxemia as a determinant of vigilance impairment in sleep apnea syndrome. , 1991, Chest.

[27]  L. Findley,et al.  Automobile accidents in patients with sleep apnea syndrome. An epidemiological and mechanistic study. , 1998, American journal of respiratory and critical care medicine.

[28]  D. Gozal,et al.  Oxidant stress and inflammation in the snoring child: confluent pathways to upper airway pathogenesis and end-organ morbidity. , 2006, Sleep medicine reviews.

[29]  F. J. Nieto,et al.  Relation of sleepiness to respiratory disturbance index: the Sleep Heart Health Study. , 1999, American journal of respiratory and critical care medicine.

[30]  M. Johns,et al.  A new method for measuring daytime sleepiness: the Epworth sleepiness scale. , 1991, Sleep.