title: Do gene variants influencing adult adiposity affect birth weight? A population-based study of 24 loci in 4,744 Danish individuals.
abstract: BACKGROUND
  Several obesity risk alleles affecting adult adiposity have been identified by the recent wave of genome wide association studies. We aimed to examine the potential effect of these variants on fetal body composition by investigating the variants in relation to birth weight and ponderal index of the newborn.
  
  
  RESULTS
  Midwife records from the Danish State Archives provided information on mother's age, parity, as well as birth weight, birth length and prematurity of the newborn in 4,744 individuals of the population-based Inter99 study. Twenty-four risk alleles showing genome-wide associations with adult BMI and/or waist circumference were genotyped. None of the 24 risk variants tested showed an association with birth weight or ponderal index after correction for multiple testing. Birth weight was divided into three categories low (≤10(th) percentile), normal (10(th)-90(th) percentile) and high birth weight (≥90th percentile) to allow for non-linear associations. There was no difference in the number of risk alleles between the groups (p = 0.57). No interactions between each risk allele and birth weight in the prediction of adult BMI were observed. An obesity risk score was created by summing up risk alleles. The risk score did not associate with fetal body composition. Moreover there was no interaction between the risk score and birth weight/ponderal index in the prediction of adult BMI.
  
  
  CONCLUSIONS
  24 common variants associated with adult adiposity did not affect or interact with birth weight among Danes suggesting that the effects of these variants predominantly arise in the post-natal life.
authors.affiliation: Hagedorn Research Institute, Gentofte, Denmark.
authors.forename: Ehm A
authors.initials: EA
authors.lastname: Andersson
authors.forename: Kasper
authors.initials: K
authors.lastname: Pilgaard
authors.forename: Charlotta
authors.initials: C
authors.lastname: Pisinger
authors.forename: Marie N
authors.initials: MN
authors.lastname: Harder
authors.forename: Niels
authors.initials: N
authors.lastname: Grarup
authors.forename: Kristine
authors.initials: K
authors.lastname: Færch
authors.forename: Camilla
authors.initials: C
authors.lastname: Sandholt
authors.forename: Pernille
authors.initials: P
authors.lastname: Poulsen
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Witte
authors.forename: Torben
authors.initials: T
authors.lastname: Jørgensen
authors.forename: Allan
authors.initials: A
authors.lastname: Vaag
authors.forename: Oluf
authors.initials: O
authors.lastname: Pedersen
authors.forename: Torben
authors.initials: T
authors.lastname: Hansen
mesh_terms: D050154:Adiposity / Q000235:genetics*; D000483:Alleles; D001724:Birth Weight; D001823:Body Composition; D015992:Body Mass Index; D003718:Denmark; D005260:Female; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008957:Models, Genetic; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy