59 Rey de Castro J, Ortiz O, Rosales-Mayor E, Ferreyra J, Liendo A, Liendo CH Sleep Sci. 2013;6(2):59-65 Prevalence of sleep-disordered breathing in truck drivers at a mine located at high altitude ORIGINAL ARTICLE Prevalencia de trastornos respiratorios del sueño en conductores de una mina de altura Jorge Rey de Castro 1,2 , Oswaldo Ortiz 3 , Edmundo Rosales-Mayor 4 , Jenny Ferreyra 1 , Alicia Liendo 5 , César Hernan Liendo 6 Study carried out at Centro de Trastornos Respiratorios del Sueño (CENTRES) - Clínica Anglo Americana - Lima, Peru 1 Centro de Trastornos Respiratorios del Sueño (CENTRES) - Clínica Anglo Americana - Lima, Peru. 2 Universidad Peruana Cayetano Heredia - Lima, Peru. 3 Rio Tinto Minera Perú - Cajamarca, Peru. 4 Instituto Clínic del Tórax, Hospital Clínic de Barcelona - Barcelona, Spain. 5 Dominican University - River Forest, IL, United States. 6 Louisiana State University - Shreveport, LA, United States Corresponding author: Jorge Rey de Castro. Rua: Alfredo Salazar, nº 350. San Isidro. Lima. Peru. E-mail: jreydecastrom@gmail.com Received: December 17, 2012; Accepted: March 18, 2013. ABSTRACT Objectives: To determine the prevalence of sleep-disorde- red breathing in Peruvian truck drivers working at high altitudes and to validate the automatic versus manual scoring system of a respiratory polygraph test. Methods: A cross-sectional and proba- bilistic study was conducted on truck drivers working the day shift at 2,020 meters above sea level. The collected information included anthropometric variables, the Epworth Sleepiness Scale (ESS), and the Lake Louise Acute Mountain Sickness (AMS) Questionnaire. A simplifed type III screening instrument was used, and each re- cording was scored both automatically and manually. Results: In a total population of 70 drivers, 63 respiratory polygraph tests were conducted and four recordings were excluded. Out of the fnal sample of 59 (84%) drivers, 46 (78%) were normal, seven (12%) had altitude-induced central sleep apnea, and six (10%) showed obstructive sleep apnea-hypopnea syndrome. The results from the ESS and the Lake Louise AMS Questionnaire were normal for all three groups. Six out of seven drivers with central sleep apnea were intermittently exposed to altitude. No demographic variable was able to predict the abnormal test results. The automatic and manual methods for scoring respiratory events were similar according to the Pearson correlation and the Bland-Altman analysis; r = 0.992 for the apnea-hypopnea index (p < 0.001) and r = 0.945 for the central sleep apnea index (p < 0.001). Conclusion: A high preva- lence of sleep-disordered breathing was observed, and no predic- tive variables for an abnormal study were identifed. The use of simplifed instruments is recommended to identify sleep-disordered breathing in drivers working at high altitudes who are far away from specialized sleep laboratories. Keywords: altitude, automobile driving, sleep-disordered breathing. RESUMEN Objetivos: Determinar la prevalencia de trastornos respiratorios del sueño en conductores peruanos que trabajan en la altura y vali- dar el sistema de califcación automático vs. manual de un polígrafo respiratorio. Métodos: Estudio transversal y probabilístico realiza- do en conductores de vehículos de doble tracción que laboran a 2020 msnm en turno diurno. La información recopilada incluyó INTRODUCTION Sleep-disordered breathing (SDB), especially sleep apnea-hypo- pnea syndrome (SAHS), has a high prevalence in the general population, irrespective of gender (1-5) . The prevalence of this epidemiologic variable fuctuates between 3-6% for symptomat- ic SAHS and 24-26% for asymptomatic SAHS. SAHS causes drowsiness, poor sleep quality, poor quality of life, neurocogni- tive defcits, and cardiorespiratory complications (6) . The preva- lence of SAHS is higher in drivers than in the general population, fuctuating between 17%-28% (7-9) . SAHS-associated risks include arterial hypertension, coronary heart disease, cerebrovascular Palabras clave: altitud, conducción de automóvil, trastornos res- piratorios del sueño. variables antropométricas, Escala de Somnolencia Epworth y cues- tionario de Lake Louis. Se utilizó un dispositivo simplifcado de tipo III y cada registro fue califcado en forma automática y manual. Resultados: En un universo de 70 conductores se realizaron 63 poligrafías respiratorias, excluyéndose 4 registros. Muestra fnal en 59 (84%) conductores: 46 (78%) fueron normales, 7 (12%) mostra- ron apnea central de altura y 6 (10%) síndrome de apnea hipopnea obstructiva del sueño. Los resultados de la Escala de Somnolencia Epworth y el cuestionario Lake Louis fueron normales en los tres grupos. Seis de 7 conductores con apnea central estuvieron expuestos intermitentemente a la altura. Ninguna variable demográfca tuvo capacidad predictiva de estudio anormal. La califcación de eventos respiratorios en forma automática y manual fue similar de acuerdo a la correlación de Pearson y el análisis de Bland-Altman: para el índice apnea hipopnea r = 0,992 (p < 0,001) e índice apnea central r = 0,945 (p < 0,001). Conclusión: Se encontró alta prevalencia de trastornos respiratorios del sueño y no se identifcaron variables que predecirían un resultado anormal. Los resultados obtenidos por método automático y manual fueron similares. Se recomienda usar dispositivos simplifcados para identifcar trastornos respirato- rios del sueño en conductores que laboran en localidades ubicadas en la altura y distantes de laboratorios del sueño especializados.