Polysomnography in Bolivian Children Native to High Altitude Compared to Children Native to Low Altitude
Catherine Mary Hill, BM, MSc, MRCP, FRCPCH, ES1,2; Annette Carroll, BSc3; Dagmara Dimitriou, PhD4; Johanna Gavlak, PhD2,5; Kate Heathcote, MB ChB, FRCS6; Veline L'Esperance, BM, MSc7; Ana Baya, PhD8; Rebecca Webster, PhD9; Maria Pushpanathan, PhD10; Romola Starr Bucks, PhD10
1Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, UK; 2Southampton Children's Hospital, Southampton, UK; 3Sleep Disorders Unit, Canberra Hospital, Australia; 4Lifespan Learning and Sleep Laboratory, UCL Institute of Education, UK; 5Neurosciences Unit, UCL Institute of Child Health, UK; 6Department of Otolaryngology, Poole General Hospital, UK; 7Department of Primary Care and Population Health, Kings College London, UK; 8Department of Psychology, Universidad Privada de Santa Cruz de la Sierra, Santa Cruz, Bolivia; 9Laboratory for Cancer Medicine, Harry Perkins Institute of Medical Research and University of Western Australia Centre for Medical Research, Perth, Australia; 10School of Psychology, University of Western Australia, Perth, Australia
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.
Hill CM, Carroll A, Dimitriou D, Gavlak J, Heathcote K, L'Esperance V, Baya A, Webster R, Pushpanathan M, Bucks RS. Polysomnography in Bolivian children native to high altitude compared to children native to low altitude. SLEEP 2016;39(12):2149–2155.