Sleep apnoea in school-age children living at high and low altitude

Abstract

<b>Introduction:</b> In adult highlanders, sleep apnoea is more common than in lowlanders (Latshang et al. Eur Respir J 2017). We evaluated the sleep apnoea prevalence in children living at high altitude compared to age-matched low altitude controls. <b>Methods:</b> Healthy children, 7-14 y of age, living at 2500-3500m in the Tien Shan mountains, Kyrgyzstan, were prospectively studied in a health post at 3250m. Healthy controls of similar age living at 700-800m were studied in a University Hospital at 760m in Bishkek. Assessments included clinical examination, medical history, the pediatric sleep questionnaire (PSQ, range 0 to 1 with increasing symptoms) and respiratory sleep studies scored according to pediatric standards. <b>Results:</b> In children living at high altitude (n = 37, 17 girls, median [quartiles] age 10.8y [9.6;13.0]), sleep studies revealed: mean nocturnal pulse oximetry 90% (89;91), oxygen desaturation index (ODI, &gt;3% dips) 4.3/h (2.5;6.7), apnoea/hypopnoea index (AHI) total 1.0/h (0.5;1.6), central 0.9/h (0.4;1.1), PSQ 0.27 (0.18;0.45). In low-altitude controls (n=41, 17 girls, age 11.6y [9.5;13.0], P between-groups=0.69) sleep studies revealed: pulse oximetry 97% (96;97), ODI 0.7/h (0.2;1.2), AHI&nbsp;total 0.1 (0.0;0.4), central 0.0 (0.0;0.2), PSQ 0.18 (0.14;0.31); P&lt;0.05 all between-group comparisons. <b>Conclusions:</b> In school-aged children living at high altitude, nocturnal oxygen saturation was lower, and the total and central apnoea/hypopnoea index were higher compared to children living at low altitude. The greater score of sleep symptoms in children residing at high altitude suggests a potential clinical relevance of the nocturnal hypoxemia and subtle sleep-related breathing disturbances.