Validation of G-protein beta-3 subunit gene C825T polymorphism as predictor of obesogenic epidemics in overweight/obese Korean children / 한국영양학회지

PURPOSE: We investigated the potential interaction between the G-protein beta-3 subunit gene (GNB3) C825T polymorphism, a risk factor for chronic disease in various ethnicities, and obesogenic environments in overweight/obese Korean children. METHODS: The present study was conducted as a cross-sectional study using measures of anthropometry, blood pressure (BP), and fasting blood samples as well as 3-day food records. Subjects were recruited from seven elementary schools in an urban district in Seoul, South Korea, between 2007 and 2008. A total of 1,260 children aged 8-9 years were recruited in the study, including 633 boys (50.3%) and 627 girls (49.7%). RESULTS: The allele frequencies of the GNB3 polymorphism were C allele = 49.7% and T allele = 50.3% in subjects. In general, boys with T allele had higher BMI, systolic BP (SBP), and triglycerides, although their energy intake was not significantly different from boys with C allele. In contrast to boys, girls with T allele had lower BMI but higher SBP and energy intake than those with C allele. The girls with T allele had a significantly lower BMI and waist circumference in both the normal weight group and obese group (OB). T allele carriers in both genders had significantly higher TC than C allele carriers in the OB group. At last, girls with T allele in OB appeared to have significantly lower HOMA-IR than those with C allele. CONCLUSION: Unlike higher risk for negative health outcomes by the GNB3 polymorphism in various ethnicities, GNB3 polymorphism did not influence obesogenic environments in overweight/obese Korean children.

Association of GNB3 C825T polymorphism with plasma electrolyte balance and susceptibility to hypertension

The role of G-protein activation in cardiovascular disorders is well-known. G-protein β3 subunit (GNB3) C825T polymorphism is associated with increased intracellular signal transduction. We investigated the role of the variant in plasma sodium and potassium concentrations and association with hypertension. 345 healthy controls and 455 patients with essential hypertension were enrolled. Plasma renin activity and aldosterone concentration were measured. The variant, typed by SNaPshot, was analyzed on an ABI Prism 3100 Genetic Analyzer and GeneScan. The TT genotype and T allele were over-represented in the patients (p < 0.001, p < 0.0001). Multiple-logistic regression disclosed that the risk of hypertension was significantly greater for TT (p < 0.0001, OR = 6.1, CI = 2.9-12.7). One-way ANOVA revealed that hypertensive T-allele carriers (CT+TT), compared to non-carriers (CC), had a greater body mass index (BMI), mean arterial pressure (MAP) and PAC (p = 0.01, p = 0.01, p < 0.0001, respectively); while the patients with 825TT risk genotype showed higher plasma sodium and lower potassium (p < 0.0001, each). The results strongly emphasize, not only the role of C825T polymorphism by the induction of increased G-protein activity and enhancement of Na/h exchangers, but also the association with higher plasma sodium and lower potassium levels, high BMI and susceptibility to hypertension.