title: Underlying factors associated with anemia in Amazonian children: a population-based, cross-sectional study.
abstract: BACKGROUND
  Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey.
  
  
  METHODS
  We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelândia, northwest Brazil, to estimate the prevalence of anemia and iron deficiency by measuring hemoglobin, erythrocyte indices, ferritin, soluble transferrin receptor, and C-reactive protein concentrations. Children were simultaneously screened for vitamin A, vitamin B(12), and folate deficiencies; intestinal parasite infections; glucose-6-phosphate dehydrogenase deficiency; and sickle cell trait carriage. Multiple Poisson regression and adjusted prevalence ratios (aPR) were used to describe associations between anemia and the independent variables.
  
  
  RESULTS
  The prevalence of anemia, iron deficiency, and iron-deficiency anemia were 13.6%, 45.4%, and 10.3%, respectively. Children whose families were in the highest income quartile, compared with the lowest, had a lower risk of anemia (aPR, 0.60; 95%CI, 0.37-0.98). Child age (<24 months, 2.90; 2.01-4.20) and maternal parity (>2 pregnancies, 2.01; 1.40-2.87) were positively associated with anemia. Other associated correlates were iron deficiency (2.1; 1.4-3.0), vitamin B(12) (1.4; 1.0-2.2), and folate (2.0; 1.3-3.1) deficiencies, and C-reactive protein concentrations (>5 mg/L, 1.5; 1.1-2.2).
  
  
  CONCLUSIONS
  Addressing morbidities and multiple nutritional deficiencies in children and mothers and improving the purchasing power of poorer families are potentially important interventions to reduce the burden of anemia.
authors.affiliation: Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil. marlyac@usp.br
authors.forename: Marly A
authors.initials: MA
authors.lastname: Cardoso
authors.forename: Kézia K G
authors.initials: KK
authors.lastname: Scopel
authors.forename: Pascoal T
authors.initials: PT
authors.lastname: Muniz
authors.forename: Eduardo
authors.initials: E
authors.lastname: Villamor
authors.forename: Marcelo U
authors.initials: MU
authors.lastname: Ferreira
mesh_terms: D000740:Anemia / Q000097:blood / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007223:Infant; D007501:Iron / Q000378:metabolism; D008297:Male; D011990:Receptors, Transferrin / Q000097:blood / Q000737:chemistry; D012307:Risk Factors; D012995:Solubility
chemical_list: D006454:Hemoglobins; D011990:Receptors, Transferrin; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron