title: Altitude correction for hemoglobin.
abstract: OBJECTIVE
  To propose a correction for the hemoglobin (Hb) increase induced by altitude-associated hypoxia.
  
  
  METHODS
  Part of a national study of nutrition and health of preschool children (0-59 months), based on a stratified, probabilistic, cluster sample.
  
  
  METHODS
  Coastal and Andean regions of Ecuador, comprising about 97% of the population, living at altitudes ranging from sea level to 3400 m.
  
  
  METHODS
  Subsample of 469 girls and boys, 6-59 months old, with normal iron (Fe) status parameters, i.e serum ferritin > or = 10 micrograms/l, transferrin saturation > or = 12%, zinc protoporphyrin < or = 2.8 micrograms/g Hb.
  
  
  RESULTS
  Exponential regression curves are adapted through the Hb values of the children, grouped by altitude ranges, and through the data reported by Hurtado in 1945 for male adults. From these exponential curves, correction factors for Hb are derived for altitudes ranging from sea level to 3400 m.
  
  
  CONCLUSIONS
  The striking parallelism between the hypoxia-induced hemoglobin increase with altitude in young children (girls and boys) and that in male adults strongly suggests that the proposed correction factors for Hb are applicable for all ages and possibly both genders, at least in the Andes.
authors.affiliation: Nestlé Research Centre, Nestec Ltd, Lausanne, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Dirren
authors.forename: M H
authors.initials: MH
authors.lastname: Logman
authors.forename: D V
authors.initials: DV
authors.lastname: Barclay
authors.forename: W B
authors.initials: WB
authors.lastname: Freire
mesh_terms: D000328:Adult; D000531:Altitude; D000704:Analysis of Variance; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D006400:Hematocrit; D006453:Hemoglobinopathies / Q000097:blood* / Q000209:etiology / Q000628:therapy; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000150:complications; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010865:Pilot Projects; D012044:Regression Analysis
chemical_list: D006454:Hemoglobins