Obesity reveals an association between blood pressure and the G-protein beta3-subunit gene: a study of female dizygotic twins

Pharmacogenetics. 2004 Jul;14(7):419-27. doi: 10.1097/01.fpc.0000114748.08559.ad.

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.

Publication types

  • Twin Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Blood Pressure / physiology*
  • Body Mass Index
  • Body Size
  • European Continental Ancestry Group / genetics
  • Female
  • Heterotrimeric GTP-Binding Proteins / genetics*
  • Humans
  • Hypertension / epidemiology
  • Hypertension / genetics*
  • Middle Aged
  • Obesity / genetics*
  • Polymorphism, Single Nucleotide / genetics*
  • Risk Factors
  • Twins, Dizygotic

Substances

  • G-protein beta3 subunit
  • Heterotrimeric GTP-Binding Proteins