An epidemiological study of blood pressure and metabolic phenotypes in relation to the Gbeta3 XXXX polymorphism.

@entity1 @entity14644 @entity14643 @entity28
BACKGROUND: The 825T allele of the @entity14644 gene is associated with increased intracellular signalling and adipogenesis in experimental studies. We studied the @entity14643 polymorphism in relation to blood pressure, @entity28 and intermediate phenotypes in a Caucasian population. METHODS: We genotyped 737 @entity1 and 775 @entity1 (participation rate, 64.3%) enrolled in a Belgian population study. Dichotomous phenotypes were tested for association with the @entity14643 polymorphism by Fisher's exact test and multiple logistic regression. For continuous traits, we used analysis of covariance and generalized estimating equations. RESULTS: The T allele (39.7 versus 29.1%) and TT genotype (16.1 versus 7.7%) were more prevalent in @entity28 @entity1 than in non- @entity28 @entity1 (P < or = 0.01). TT homozygous @entity1 , compared with C allele carriers, had higher daytime ambulatory blood pressure (mean systolic/diastolic differences, 3.6/2.5 mmHg; P < or = 0.02), higher body weight (2.7 kg, P = 0.04), greater risk of @entity28 (risk ratio, 1.90; P = 0.005), increased triceps skinfold thickness (2.3 mm, P = 0.007), higher serum insulin concentration (4.1 mU/l, P = 0.006), more insulin resistance (P = 0.01), and increased erythrocyte count (0.11 x 1012 cells/l, P = 0.04) and haematocrit (0.9%, P = 0.02). In @entity1 , haematocrit and erythrocyte count were also higher (P < or = 0.03) in T allele carriers, but other phenotypes were not correlated with the @entity14643 polymorphism. CONCLUSION: Male and female carriers of the T allele at position 825 of the @entity14644 gene have a slightly higher haematocrit and erythrocyte count. Male TT homozygotes have a higher blood pressure and are more @entity28 and insulin-resistant than C allele carriers. We speculate that the higher blood pressure in TT homozygous @entity1 might arise via a metabolic pathway characterized by @entity28 and insulin resistance as well as via increased peripheral resistance secondary to the higher haematocrit.
