title: Individual and combined effects of ApoE and MTHFR 677C/T polymorphisms on cognitive performance in Spanish adolescents: the AVENA study.
abstract: OBJECTIVE
  To examine the individual and combined associations of ApoE and MTHFR 677C/T polymorphisms with cognitive performance in adolescents.
  
  
  METHODS
  The study comprised 412 Spanish adolescents (13 to 18.5 years of age). Cognitive performance (verbal, numeric and reasoning abilities, and an overall score) was measured by the Spanish-version of the SRA-Test of Educational-Ability.
  
  
  RESULTS
  We observed no differences in the cognitive performance study variables in adolescents carrying or not carrying the ApoE epsilon4 variant. Adolescents without the MTHFR 677TT genotype had significantly better cognitive performance than their TT peers. The analysis of the combined effect of these polymorphisms revealed that those individuals carrying both the ApoE epsilon4 variant and the MTHFR 677TT genotype had significantly worse cognitive performance than their peers with other genotype combinations. These findings were independent of sex, age pubertal status, socioeconomic status, physical activity, and skipping breakfast.
  
  
  CONCLUSIONS
  The results of the present study suggest that the ApoE epsilon4 alone is not associated with cognitive performance in adolescents. Individuals with the MTHFR 677TT genotype had slightly impaired cognitive performance, whereas we observed a combined effect of both the ApoE epsilon4 variant and the MTHFR 677TT genotype on cognitive performance. More research is needed in larger population samples to corroborate our findings.
authors.affiliation: Unit for Preventive Nutrition, Department of Biosciences and Nutrition at NOVUM, Karolinska Institutet, Huddinge, Sweden. Electronic address: ruizj@ugr.es.
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
authors.affiliation: Department of Basic Psychology, School of Psychology, University of Málaga, Spain.
authors.forename: Ruth
authors.initials: R
authors.lastname: Castillo
authors.affiliation: Department of Nutrition and Food Science, University of the Basque Country, Vitoria, Spain.
authors.forename: Idoia
authors.initials: I
authors.lastname: Labayen
authors.affiliation: Department of Physiotherapy and Nursing, School of Health Sciences, University of Zaragoza, Zaragoza, Spain.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.affiliation: Department of Pediatrics, University of Cantabria, Santander, Spain.
authors.forename: Miguel García
authors.initials: MG
authors.lastname: Fuentes
authors.affiliation: Department of Pediatrics, University of Cantabria, Santander, Spain.
authors.forename: Domingo González
authors.initials: DG
authors.lastname: Lamuño
authors.affiliation: Department of Pediatrics, University of Cantabria, Santander, Spain.
authors.forename: Jesus L
authors.initials: JL
authors.lastname: Alvarez Granda
authors.affiliation: Universidad Europea de Madrid, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Lucia
authors.affiliation: Unit for Preventive Nutrition, Department of Biosciences and Nutrition at NOVUM, Karolinska Institutet, Huddinge, Sweden; Department of Medical Physiology, School of Medicine, University of Granada, Spain.
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
mesh_terms: D000293:Adolescent; D053327:Apolipoprotein E4 / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D006710:Homocysteine / Q000502:physiology; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic; D012959:Socioeconomic Factors; D013030:Spain; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D006710:Homocysteine; D042965:Methylenetetrahydrofolate Reductase (NADPH2)