title: Prospective analysis of the association of a common variant of FTO (rs9939609) with adiposity in children: results of the IDEFICS study.
abstract: OBJECTIVE
  We investigated cross-sectionally and longitudinally the relationship between FTO rs9939609 and obesity-related characteristics in the European children of the IDEFICS project and the interaction of this variant with a lifestyle intervention.
  
  
  METHODS
  A cohort of 16224 children (2-9 years) was recruited into a population-based survey (T0) from eight European countries. A second survey (T1) reassessed the children two years later. A random sample of 4405 children was extracted for genetic studies. 3168 children were re-examined two years later. Half of them underwent a lifestyle intervention program. The FTO rs9939609 was genotyped. Weight, height, waist circumference, triceps and subscapular skinfolds were measured at T0 and T1.
  
  
  RESULTS
  At T0, the risk A allele of rs9939609 was significantly associated with higher values of body mass index (BMI), waist circumference and skinfolds (age, sex, and country-adjusted p-values: all p<0.001) and with a statistically significant increased risk of overweight/obesity. Over the two year follow-up, no interaction between genotype and intervention was observed. The A allele was associated to a significantly higher increase in all the anthropometric variables examined at T0 independently from the study group (intervention versus control) (p-values: all p<0.002, adjusted for age, sex, country, intervention/control study group, T0 values, and individual time interval between T0 and T1). Over the two-year follow-up, 210 new cases of overweight/obesity occurred. A statistically significant higher incidence of overweight/obesity was associated to the A allele [OR(A) = 1.95, 95% CI = (1.29; 2.97)].
  
  
  CONCLUSIONS
  We confirmed the association between the FTO rs9939609 and body mass and overweight/obesity risk in European children. The main finding of the study is that the A allele carriers present higher increase of body mass and central adiposity over time and higher risk of developing overweight/obesity during growth, independently from intervention measures.
authors.affiliation: Unit of Epidemiology and Population Genetics, Institute of Food Sciences, Consiglio Nazionale delle Ricerche, Avellino, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Lauria
authors.forename: Alfonso
authors.initials: A
authors.lastname: Siani
authors.forename: Karin
authors.initials: K
authors.lastname: Bammann
authors.forename: Ronja
authors.initials: R
authors.lastname: Foraita
authors.forename: Inge
authors.initials: I
authors.lastname: Huybrechts
authors.forename: Licia
authors.initials: L
authors.lastname: Iacoviello
authors.forename: Anna C
authors.initials: AC
authors.lastname: Koni
authors.forename: Yannis
authors.initials: Y
authors.lastname: Kourides
authors.forename: Staffan
authors.initials: S
authors.lastname: Marild
authors.forename: Denes
authors.initials: D
authors.lastname: Molnar
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Iris
authors.initials: I
authors.lastname: Pigeot
authors.forename: Yannis P
authors.initials: YP
authors.lastname: Pitsiladis
authors.forename: Toomas
authors.initials: T
authors.lastname: Veidebaum
authors.forename: Paola
authors.initials: P
authors.lastname: Russo
mesh_terms: D050154:Adiposity / Q000235:genetics*; D000483:Alleles; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D009765:Obesity / Q000235:genetics; D050177:Overweight / Q000235:genetics*; D011446:Prospective Studies; D011506:Proteins / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D011506:Proteins; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human