Background: Diabetes mellitus type 2 results from a complex of hereditary and environmental factors. Genes encoding elements of the G-protein system are candidate genes in hypertension and
obesity. Since insulin uses G-sensitive mechanisms to enhance tissue glucose uptake and vasodilatation, the GNB3 gene may be a candidate gene in type 2 diabetes. The goal of our research was to determine if the C825T polymorphism at the G-protein β3 subunit gene locus is associated with type 2 diabetes.
Material/Methods: The study population consisted of 172 Polish patients with type 2 diabetes and 172 healthy, age- and sex-matched controls. The C825T polymorphism was detected by PCR and RFLP.
Results: A higher frequency of genotypes containing the mutation (CT+TT) was observed among the diabetics than in the controls. The T825 variant occurred more often among hypertensive diabetics (71%) than among diabetics with normal blood pressure (42.5%). The OR for hypertension in diabetic subjects bearing CT+TT genotypes was higher than in patients with the CC genotype. Overweight and obesity were not associated with the T825 variant in either the experimental subjects or the controls.
Conclusions: In this population, the T825 variant of the GNB3 gene was not associated with type 2 diabetes itself, nor with overweight and obesity, but was associated with diabetic hypertension. Upon
confirmation of our results this variant may be useful as a genetic marker of susceptibility to hypertension and vascular complications in type 2 diabetes.

Keywords: Diabetes Mellitus, Type 2 - complications