title: Head size and intelligence, learning, nutritional status and brain development. Head, IQ, learning, nutrition and brain.
abstract: This multifactorial study investigates the interrelationships between head circumference (HC) and intellectual quotient (IQ), learning, nutritional status and brain development in Chilean school-age children graduating from high school, of both sexes and with high and low IQ and socio-economic strata (SES). The sample consisted of 96 right-handed healthy students (mean age 18.0 +/- 0.9 years) born at term. HC was measured both in the children and their parents and was expressed as Z-score (Z-HC). In children, IQ was determined by means of the Wechsler Intelligence Scale for Adults-Revised (WAIS-R), scholastic achievement (SA) through the standard Spanish language and mathematics tests and the academic aptitude test (AAT) score, nutritional status was assessed through anthropometric indicators, brain development was determined by magnetic resonance imaging (MRI) and SES applying the Graffar modified method. Results showed that microcephalic children (Z-HC < or = 2 S.D.) had significantly lower values mainly for brain volume (BV), parental Z-HC, IQ, SA, AAT, birth length (BL) and a significantly higher incidence of undernutrition in the first year of life compared with their macrocephalic peers (Z-HC > 2S.D.). Multiple regression analysis revealed that BV, parental Z-HC and BL were the independent variables with the greatest explanatory power for child's Z-HC variance (r(2) = 0.727). These findings confirm the hypothesis formulated in this study: (1) independently of age, sex and SES, brain parameters, parental HC and prenatal nutritional indicators are the most important independent variables that determine HC and (2) microcephalic children present multiple disorders not only related to BV but also to IQ, SA and nutritional background.
authors.affiliation: Public Nutrition Area, Institute of Nutrition and Food Technology, University of Chile, Avda. Macul 5540, P.O. Box 138-11, Santiago, Chile. inta8@abello.dic.uchile.cl
authors.forename: Daniza M
authors.initials: DM
authors.lastname: Ivanovic
authors.forename: Boris P
authors.initials: BP
authors.lastname: Leiva
authors.forename: Hernán T
authors.initials: HT
authors.lastname: Pérez
authors.forename: Manuel G
authors.initials: MG
authors.lastname: Olivares
authors.forename: Nora S
authors.initials: NS
authors.lastname: Díaz
authors.forename: María Soledad C
authors.initials: MS
authors.lastname: Urrutia
authors.forename: Atilio F
authors.initials: AF
authors.lastname: Almagià
authors.forename: Triana D
authors.initials: TD
authors.lastname: Toro
authors.forename: Patricio T
authors.initials: PT
authors.lastname: Miller
authors.forename: Enrique O
authors.initials: EO
authors.lastname: Bosch
authors.forename: Cristián G
authors.initials: CG
authors.lastname: Larraín
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D001077:Aptitude Tests; D001921:Brain / Q000254:growth & development* / Q000473:pathology; D002508:Cephalometry; D002648:Child; D002657:Child Development / Q000502:physiology; D002677:Chile; D004522:Educational Status; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007360:Intelligence / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008831:Microcephaly / Q000175:diagnosis; D015596:Nutrition Assessment; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011502:Protein-Energy Malnutrition / Q000175:diagnosis / Q000523:psychology; D011594:Psychometrics; D012959:Socioeconomic Factors; D014888:Wechsler Scales / Q000706:statistics & numerical data