Association between a polymorphism in the G protein β3 subunit gene (GNB3) with arterial hypertension but not with myocardial infarction

OBJECTIVE: A polymorphism at position 825(C-->T) of the G protein beta3 (GNB3) gene was found to be associated with enhanced transmembrane signalling as well as with an increased prevalence of arterial hypertension. The aim of the present study was to further investigate the association of the GNB3 C825T allele status with arterial hypertension in a large population-based sample and its association with specific end organ damage, i.e. myocardial infarction (MI). METHODS: Individuals from a population-based sample (n=2052) and patients suffering from premature MI (age at first MI < or = 60 years, n = 606) were studied by questionnaire as well as by physical examination and biochemical analyses. RESULTS: In the population-based sample, the prevalence of arterial hypertension (blood pressure > or = 160/95 mmHg and/or antihypertensive medication) was higher in individuals with the TT genotype (41.8%) as compared to heterozygote individuals (36.6%) or those with the CC genotype (32.75%) (P = 0.02). This association was predominantly found in men. Moreover, men without antihypertensive medication carrying the TT genotype showed higher diastolic blood pressure than those carrying the CC genotype (86.5 vs. 83.7 mmHg, P = 0.04). However, the genotype distribution and the allele frequencies were similar in both, the population-based and the MI patient sample. Furthermore, neither the age at the time of MI nor the location of the MI were related to the genotype distribution. Similarly, gender and age stratified analyses did not show any association of the GNB3 genotype and MI. CONCLUSIONS: In male individuals from a large population-based sample, the T allele of the GNB3 polymorphism was associated with arterial hypertension. However, the effects of the GNB3 825T allele on blood pressure were small and did not translate to a clinically relevant increase of risk for MI.