title: Polysomnography in Bolivian Children Native to High Altitude Compared to Children Native to Low Altitude.
abstract: To compare polysomnographic parameters in high altitude (HA) native Andean children with low altitude (LA) native peers in order to explain the nocturnal oxyhemoglobin saturation (SpO2) instability reported in HA native children and to study the effect on sleep quality.
  
  
  
  Ninety-eight healthy children aged 7-10 y and 13-16 y were recruited at LA (500 m) or HA (3,650 m) above sea level. Physical examination was undertaken and genetic ancestry determined from salivary DNA to determine proportion of European ancestry, a risk factor for poor HA adaptation. Attended polysomnography was carried out over 1 night for 58 children at their resident location.
  
  
  
  Of 98 children recruited, 85 met inclusion criteria, 58 of 85 (68.2%) completed polysomnography, of which 56 were adequate for analysis: 30 at LA (17 male) and 26 at HA (16 male). There were no altitude differences in genetic ancestry, but a high proportion of European admixture (median 50.6% LA; 44.0% HA). SpO2 was less stable at HA with mean 3% and 4% oxygen desaturation indices greater (both P < 0.001) than at LA. This was not explained by periodic breathing. However, more obstructive hypopnea was observed at HA (P < 0.001), along with a trend toward more central apnea (P = 0.053); neither was explained by clinical findings. There was no difference in sleep quality between altitudes.
  
  
  
  HA native Andean children have more respiratory events when scoring relies on SpO2 desaturation due to inherent SpO2 instability. Use of American Academy of Sleep Medicine scoring criteria may yield false-positive results for obstructive sleep-disordered breathing at HA.
authors.affiliation: Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, UK.|Southampton Children's Hospital, Southampton, UK.
authors.forename: Catherine Mary
authors.initials: CM
authors.lastname: Hill
authors.affiliation: Sleep Disorders Unit, Canberra Hospital, Australia.
authors.forename: Annette
authors.initials: A
authors.lastname: Carroll
authors.affiliation: Lifespan Learning and Sleep Laboratory, UCL Institute of Education, UK.
authors.forename: Dagmara
authors.initials: D
authors.lastname: Dimitriou
authors.affiliation: Southampton Children's Hospital, Southampton, UK.|Neurosciences Unit, UCL Institute of Child Health, UK.
authors.forename: Johanna
authors.initials: J
authors.lastname: Gavlak
authors.affiliation: Department of Otolaryngology, Poole General Hospital, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Heathcote
authors.affiliation: Department of Primary Care and Population Health, Kings College London, UK.
authors.forename: Veline
authors.initials: V
authors.lastname: L'Esperance
authors.affiliation: Department of Psychology, Universidad Privada de Santa Cruz de la Sierra, Santa Cruz, Bolivia.
authors.forename: Ana
authors.initials: A
authors.lastname: Baya
authors.affiliation: Laboratory for Cancer Medicine, Harry Perkins Institute of Medical Research and University of Western Australia Centre for Medical Research, Perth, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Webster
authors.affiliation: School of Psychology, University of Western Australia, Perth, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Pushpanathan
authors.affiliation: School of Psychology, University of Western Australia, Perth, Australia.
authors.forename: Romola Starr
authors.initials: RS
authors.lastname: Bucks
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000293:Adolescent; D000531:Altitude; D001838:Bolivia; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D017286:Polysomnography; D012016:Reference Values; D020182:Sleep Apnea, Central / Q000175:diagnosis* / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology
chemical_list: D010108:Oxyhemoglobins
keywords: adaptation; apnea; high altitude; hypopnea; hypoxia; polysomnography; sleep-disordered breathing