title: Obesity reveals an association between blood pressure and the G-protein beta3-subunit gene: a study of female dizygotic twins.
abstract: The 825C>T polymorphism of the G-protein beta3-subunit gene (GNB3) has been associated with hypertension, although results are not entirely consistent. In a sample of 282 female Caucasian dizygotic twins aged 21-80 years, we aimed to investigate the associations between blood pressure and five single nucleotide polymorphisms (SNPs) including the 825C>T and haplotypes of the GNB3 gene. The polymorphisms (-350A>G, 657A>T, 814G>A, 825C>T and 1429C>T) were genotyped by polymerase chain reaction-restriction enzyme assays. Regular association tests did not show a significant effect on blood pressure for any of the five SNPs. However, strongly significant interactions between the -350A>G, 825C>T and 1429C>T loci and adiposity (both body mass index and waist circumference) were observed for systolic blood pressure (Ps < 0.01) as well as diastolic blood pressure (Ps < 0.05), suggesting increases in adiposity amplify the effects of the SNPs on blood pressure. Haplotype analyses confirmed the effects of the GNB3 gene-obesity interaction on hypertension risk. Additionally, sib-transmission disequilibrium tests (sib-TDTs) showed significant associations with blood pressure for the 825C>T and 1429C>T loci. In summary, the presence of obesity reveals an association between blood pressure and the GNB3 gene in White females. Our data suggest that adiposity is a final pathway through which gene-lifestyle interactions may exert their effects on the development of hypertension. Our results from the combined SNP, haplotype and sib-TDT analyses also support the hypothesis that the 825C>T is a susceptibility locus for hypertension, whereas effects of other loci on blood pressure may result from their strong linkage disequilibrium with the 825C>T locus.
authors.affiliation: Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, Georgia, USA. ydong@mcg.edu
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Dong
authors.forename: Haidong
authors.initials: H
authors.lastname: Zhu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wang
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Dalageorgou
authors.forename: Nick
authors.initials: N
authors.lastname: Carter
authors.forename: Tim D
authors.initials: TD
authors.lastname: Spector
authors.forename: Harold
authors.initials: H
authors.lastname: Snieder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D049628:Body Size; D005260:Female; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000235:genetics*; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D014429:Twins, Dizygotic; D044465:White People / Q000235:genetics
chemical_list: C454420:G-protein beta3 subunit; D020962:Heterotrimeric GTP-Binding Proteins