title: Altitude Above Sea Level and Body Mass Index as Determinants of Oxygen Saturation in Children: The SON@ Study.
abstract: BACKGROUND
  Altitude above sea level and body mass index are well-recognized determinants of oxygen saturation in adult populations; however, the contribution of these factors to oxygen saturation in children is less clear.
  
  
  OBJECTIVE
  To explore the contribution of altitude above sea level and body mass index to oxygen saturation in children.
  
  
  METHODS
  A multi-center, cross-sectional study conducted in nine cities in Mexico. Parents signed informed consent forms and completed a health status questionnaire. Height, weight, and pulse oximetry were recorded.
  
  
  RESULTS
  We studied 2,200 subjects (52% girls) aged 8.7 ± 3.0 years. Mean body mass index, z-body mass index, and oxygen saturation were 18.1 ± 3.6 kg·m-2, 0.58 ± 1.3, and 95.5 ± 2.4%, respectively. By multiple regression analysis, altitude proved to be the main predictor of oxygen saturation, with non-significant contributions of age, gender, and body mass index. According to quantile regression, the median estimate of oxygen saturation was 98.7 minus 1.7% per km of altitude above sea level, and the oxygen saturation fifth percentile 97.4 minus 2.7% per km of altitude.
  
  
  CONCLUSIONS
  Altitude was the main determinant of oxygen saturation, which on average decreased 1.7% per km of elevation from a percentage of 98.7 at sea level. In contrast with adults, this study in children found no association between oxygen saturation and obesity or age.
authors.affiliation: Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico.|Centro Médico Santa Teresa, Texcoco, Edo. de México, Mexico.
authors.forename: Laura
authors.initials: L
authors.lastname: Gochicoa-Rangel
authors.affiliation: Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico.
authors.forename: José Rogelio
authors.initials: JR
authors.lastname: Pérez-Padilla
authors.affiliation: Centro Médico Santa Teresa, Texcoco, Edo. de México, Mexico.|Laboratorio de Función Pulmonar S de RL, Mexico City, Mexico.
authors.forename: Luis
authors.initials: L
authors.lastname: Rodríguez-Moreno
authors.affiliation: Instituto de Seguridad Social al Servicio de los Trabajadores del Estado, Tepic, Nayarit, Mexico.
authors.forename: Arturo
authors.initials: A
authors.lastname: Montero-Matamoros
authors.affiliation: Respirar, Centro de Atención Pulmonar del Sureste, Mérida, Yucatán, Mexico.
authors.forename: Nancy
authors.initials: N
authors.lastname: Ojeda-Luna
authors.affiliation: Hospital General Regional No. 220 IMSS, Toluca, Edo. de México, Mexico.
authors.forename: Gema
authors.initials: G
authors.lastname: Martínez-Carbajal
authors.affiliation: Hospital de Pediatría, Unidad Médica de Alta Especialidad, Centro Médico de Occidente, IMSS, Guadalajara, Jalisco, Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Hernández-Raygoza
authors.affiliation: Unidad Médica de Alta Especialidad, IMSS, Monterrey, Nuevo León, Mexico.
authors.forename: Dolores
authors.initials: D
authors.lastname: Ruiz-Pedraza
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico.
authors.forename: María Rosario
authors.initials: MR
authors.lastname: Fernández-Plata
authors.affiliation: Department of Respiratory Physiology, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico.|Laboratorio de Función Pulmonar S de RL, Mexico City, Mexico.
authors.forename: Luis
authors.initials: L
authors.lastname: Torre-Bouscoulet
mesh_terms: D000531:Altitude; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism*; D011795:Surveys and Questionnaires
chemical_list: D010100:Oxygen