G protein beta-3 subunit polymorphism as a susceptible factor for the hypertensive patients in Korea.

Abstract

Objective: Genes encoding elements of the G-protein system were already shown to be candidate genes in hypertension in Japanese as well as in Caucasians. The goal of our research was to determine if the C825T polymorphism at the G-protein(3 subunit gene locus(GNB3) is associated with hypertension in Korea. We also wanted to study whether the GNB3 gene may be a candidate gene in type 1(T1D), type 2 diabetes(T2D) or diabetic retinopathy(DR). Design and Methods: The study consisted of 148 non-diabetic subjects either had hypertension or had taken antihypertensive drugs and 152 healthy age-, sex-matched controls. We also recruited 252 non-hypertensive T1D patints, 140 non-hypertensive T2D patients without DR, 121 T2D patients with background diabetic retinopathy(BDR), and 57 T2D patients with proliferative diabetic retinopathy(PDR). Genotypes of SNPs were determined with a fluorescence-based allele-specific DNA primer-probe assay system. Results: The TT genotype of GNB 3 C825T had a susceptible influence for the risk of hypertension with the OR of 5.93(95% CI:2.25-16.5)(p<10^4). However, the genotype distribution of the controls did not differ either from that of non-hypertensive T1D, T2D, or BDR. Overweight and obesity were not associated with the T825 variant in either the experimental subjects or the controls. Interestingly, compared with the normal controls, the TT genotype was increased in patients with PDR(OR=3.41, p< 0.05). Conclusion: In our population, the T825 variant of the GNB3 genes was not associated with diabetes, nor with overweight as a genetic marker of susceptibility to hypertension and vascular complications in type 2 diabetes.