G-protein beta 3 subunit C825T variant and ambulatory blood pressure in essential hypertension

Recent studies have identified a novel polymorphism (C825T) of the gene enc oding the beta 3 subunit of heterotrimeric G proteins (G beta 3) associated with enhanced activation of G proteins, which appears to be more common in hypertensive patients. In the present study we examine the relationship be tween this genetic variant and hypertension in 479 white patients with esta blished essential hypertension recruited from the hypertension clinic of th e Universitats-klinikum Benjamin Franklin in Berlin, Germany, and 1000 norm otensive gender- and age-matched controls. All patients were screened for t he presence of secondary hypertension and were further characterized by amb ulatory blood pressure measurements performed in 295 treated and 184 untrea ted patients. Genotype distribution for the G beta 3-C825T genotype in pati ents (CC = 204, CT = 224, TT = 51) was significantly different from that in controls (CC = 513, CT = 412, TT = 74; chi(2) = 11.5, P < 0.01), and the T allele was associated with an odds ratio of 1.5 (95% CI, 1.1 to 2.2) versu s non-T carriers for the presence of hypertension. However, in both the who le group and the untreated subgroup, blood pressure levels between the geno typic groups were virtually identical. Furthermore, age of onset of hyperte nsion and number of antihypertensive medications (in treated patients) were similar between the genotypic groups. Thus, while our data confirm the ass ociation between the G beta 3-C825T variant and essential hypertension, the y do not support the hypothesis that this marker is associated with more se vere blood pressure in patients with already established hypertension.