G protein β3 polymorphism and hemodynamic and body composition phenotypes in the HERITAGE Family Study

Abstract

. G protein ␤3 polymorphism and hemodynamic and body composition phenotypes in the HER-ITAGE Family Study. Physiol Genomics 8: 151-157, 2002. First published January 22, 2002 10.1152/physiolgenomics. 00102.2001.-A C825T polymorphism of the G protein ␤3 (GNB3) gene has been reported to be associated with hypertension and obesity. We analyzed the associations between the GNB3 C825T polymorphism and hemodynamic and body composition phenotypes in the sedentary state and their responses to endurance training in mainly normotensive white (n ϭ 473) and black (n ϭ 255) men and women. Blood pressure (BP) and heart rate (HR) were measured at rest and during submaximal exercise at constant power output (50 W), and stroke volume and cardiac output were obtained during exercise. Body composition was assessed with underwater weighing. Baseline systolic BP (SBP) at 50 W was slightly higher in the white CC homozygotes (P ϭ 0.036), whereas in blacks the CC genotype was associated with a lower resting HR (P ϭ 0.012). In blacks, the CC homozygotes showed a greater training-induced reduction in HR at 50 W (P ϭ 0.013) and a similar trend was observed also in whites (P ϭ 0.053). Black women carrying the CC genotype showed significantly greater reductions in resting SBP and diastolic BP (DBP) than the TT homozygotes, whereas in black men the changes in resting BP were similar across the genotypes (P Ͻ 0.05 for sex-by-GNB3 interactions). The GNB3 genotype was not associated with baseline body composition in blacks or whites. In blacks, the TT genotype was associated with a greater training-induced decrease in fat mass (P ϭ 0.012) and percent body fat (P ϭ 0.006). These data suggest that DNA sequence variation in the GNB3 locus is not a major modifier of endurance training-induced changes in hemodynamic and body composition phenotypes in healthy but previously sedentary subjects. The GNB3 genotype may play a minor role in HR and body fatness regulation in blacks and in responsiveness of resting BP to endurance training in black women. blood pressure; heart rate; body fatness; exercise training; genotype WHILE INVESTIGATING THE ROLE of Na ϩ

Gene–environment interaction and the GNB3 gene in the Atherosclerosis Risk in Communities Study

“…Nevertheless, there were significant differences in change in fat mass and body fat percentage in blacks only on completion of the exercise program when stratified by the GNB3 genotype, with TT homozygotes having the largest decrease in these phenotypes and the CC homozygotes showing little or no decrease. 29 Our results would also predict that TT homozygotes would be most likely to respond to exercise training, as this is the group in which inactivity is most strongly associated with obesity and hypertension. Conversely, Poston et al 30 reported that African immigrants and AAs that were 825T homozygotes were more obese than the heterozygotes and 825C homozygotes, regardless of physical activity level.…”

GNB3C825T Polymorphism and Elite Athletic Status: A Replication Study with Two Ethnic Groups

“…blood pressure to endurance training in black women [14] . It is associated with VO 2max in nonathletes [5] , and Eynon et al recently reported a higher frequency of the TT genotype in Israeli elite endurance athletes than in sprinters of the same origin [4] .…”

Acetylcholinesterase/paraoxonase genotype and expression predict anxiety scores in Health, Risk Factors, Exercise Training, and Genetics study

“…Genomic DNA was prepared from permanent lymphoblastoid cells as described (20). PCR amplification by using Taq polymerase (Sigma, D-6677) was followed by Exo-Sap enzymatic purification (United States Biochemical, US78200) of the PCR product (Table 1, which is published as supporting information on the PNAS web site).…”