title: An age-dependent diet-modified effect of the PPARγ Pro12Ala polymorphism in children.
abstract: Variation in the peroxisome proliferator-activated receptor γ gene alters the risk for adiposity in adults, with evidence of interaction with diet. We investigated the age-related association between the Pro12Ala variant (rs1801282) and diet in obesity-related traits in children. The Pro12Ala variant was assayed in 2102 young children aged 1 to 6 years and in 794 periadolescent children aged 10 to 12 years of Greek origin. In both cohorts, no differences were found in obesity traits between the Ala allele carriers and Pro/Pro homozygotes. Sex-stratified analysis showed that, in periadolescent boys, Ala carriers exhibited lower measures of skinfolds (triceps: 16.9 ± 6.9 vs 19.4 ± 7.9 mm, P = .01; subscapular: 9.6 ± 4.5 vs 11.2 ± 5.4 mm, P = .02). On the other hand, young girls who were Ala carriers presented higher measures of triceps skinfold thickness (10.5 ± 3.0 vs 9.9 ± 2.8 mm, P = .04). Nominal gene-diet interactions were revealed in periadolescents for saturated fatty acid (SFA) intake and skinfolds (P for interaction = .05). In Pro/Pro homozygous young girls, SFA and total fat (TF) intake was positively associated with higher body mass index (BMI) (P = .01), waist circumference (P = .02), and skinfold thickness (triceps-SFA: P = 10⁻⁵, triceps-TF: P = 10⁻⁹, subscapular-SFA: P = 10⁻⁶, subscapular-TF: P = 10⁻⁴). For Pro/Pro homozygotes, unsaturated fat intake was inversely associated with BMI (P = .04) in young girls, and with BMI (P = .03), waist circumference (P = .03), and triceps (P = .02) in periadolescent boys. Our results suggest that adiposity in children is influenced by the Pro12Ala polymorphism in a sex-specific and age-dependent manner. We also demonstrate evidence of an age-dependent gene-diet (SFA, TF) interaction, suggesting that the type of fat intake modifies the effect of the Pro12 allele on obesity-related measures.
authors.affiliation: Department of Dietetics-Nutrition, Harokopio University, 17671 Athens, Greece. dedousi@hua.gr
authors.forename: George V
authors.initials: GV
authors.lastname: Dedoussis
authors.forename: Yannis
authors.initials: Y
authors.lastname: Manios
authors.forename: Georgia
authors.initials: G
authors.lastname: Kourlaba
authors.forename: Stavroula
authors.initials: S
authors.lastname: Kanoni
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Lagou
authors.forename: Johannah
authors.initials: J
authors.lastname: Butler
authors.forename: Constantina
authors.initials: C
authors.lastname: Papoutsakis
authors.forename: Robert A
authors.initials: RA
authors.lastname: Scott
authors.forename: Mary
authors.initials: M
authors.lastname: Yannakoulia
authors.forename: Yannis P
authors.initials: YP
authors.lastname: Pitsiladis
authors.forename: Joel N
authors.initials: JN
authors.lastname: Hirschhorn
authors.forename: Helen N
authors.initials: HN
authors.lastname: Lyon
mesh_terms: D000375:Aging / Q000378:metabolism*; D019943:Amino Acid Substitution; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002648:Child; D004032:Diet; D004041:Dietary Fats; D005247:Feeding Behavior; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000235:genetics / Q000378:metabolism; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012741:Sexual Maturation / Q000502:physiology; D012885:Skinfold Thickness; D055105:Waist Circumference
chemical_list: D004041:Dietary Fats; D047495:PPAR gamma