ANGIOTENSIN-II TYPE-1 RECEPTOR A C-1166 POLYMORPHISM - RELATIONSHIPS WITH BLOOD-PRESSURE AND CARDIOVASCULAR STRUCTURE/

The angiotensin II type 1 (AT(1)) receptor has a key role in mediating the vasoconstrictor and growth-promoting effects of angiotensin II. I t has been reported that a polymorphism of the AT(1) receptor gene (an A/C transversion at position 1166) may be associated with cardiovascu lar phenotypes, such as arterial blood pressure and aortic stiffness, that underlie a condition of increased cardiovascular risk. We examine d a sample of 212 subjects randomly selected from a general population in northern Italy to investigate the role of AT(1) receptor gene poly morphism in the regulation of blood pressure and cardiovascular growth . We measured blood pressure (both clinic and 24-hour ambulatory recor ding), left ventricular mass (echocardiography), and carotid artery wa ll thickness (B-mode ultrasound); we assessed the AT(1) receptor genot ype by polymerase chain reaction and allele-specific oligonucleotide h ybridization. Blood pressure values were lower in CC homozygotes than in heterozygotes and AA homozygotes; the difference was statistically significant for clinic measurements (mean difference for mean blood pr essure, -6.6 mm Hg, P=.01; 95%: confidence interval, -1.6 to -11.7 mm Hg) but not for ambulatory blood pressure measurements. CC homozygotes also presented a lower incidence of a positive family history of hype rtension (P=.027). No statistically significant differences among AT(1 ) receptor A/C-1166 genotypes were observed for left ventricular mass or carotid artery wall thickness. We conclude that the present study d oes net support a major role of the AT(1) receptor gene A/C-1166 polym orphism as a marker of conditions associated with increased cardiovasc ular risk.