title: Cognitive functioning in children from Nigeria with sickle cell anemia.
abstract: Cognitive impairment is a major neurological complication of sickle cell anemia (SCA) in the United States, but there are limited studies of cognitive impairment in Nigeria, the country with the highest SCA burden. We hypothesized that children from Nigeria with SCA have worse cognitive functioning than comparison children and explored the association between lower cognitive functioning and key laboratory demographic and socioeconomic variables among children with SCA.
  
  
  
  We conducted a cross-sectional survey, supplemented by anthropomorphic and laboratory data, among a convenience sample of children from Nigeria with and without SCA. We administered the Wechsler Intelligence Scale for Children, Version IV. Our primary outcome measures included (1) estimated IQ (Est. IQ), (2) working memory (WM), and (3) processing speed (PS).
  
  
  
  The sample included 56 children with SCA (mean age 9.20 [SD 2.75], 46.43% girls) and 44 comparison children (mean age 9.41 [SD 2.49], 40.91% girls). Children with SCA performed worse on Est. IQ (84.58 vs. 96.10, P = 0.006) and PS (86.69 vs 96.91, P = 0.009) than comparison children. There was no significant difference in WM between both groups. Factors associated with lower Est. IQ and PS among children with SCA included age, maternal education, weight-for-age Z scores, and height-for age Z scores.
  
  
  
  In this small sample of children from Nigeria, we found worse cognitive functioning in children with SCA than in comparison children, and that sociodemographic and anthropomorphic factors were correlated with cognitive functioning.
authors.affiliation: School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Olubusola B
authors.initials: OB
authors.lastname: Oluwole
authors.affiliation: Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Noll
authors.affiliation: Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Winger
authors.affiliation: Sickle Cell Foundation Nigeria, Lagos, Nigeria.
authors.forename: Olu
authors.initials: O
authors.lastname: Akinyanju
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania. noveex@upmc.edu.
authors.forename: Enrico M
authors.initials: EM
authors.lastname: Novelli
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000523:psychology*; D002648:Child; D003071:Cognition; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D009549:Nigeria
keywords: IQ; Nigeria; cognitive functioning; nutrition; sickle cell anemia