A1166C polymorphism of angiotensin II type 1 receptor, blood pressure and arterial stiffness in hypertension

Objective To study the association of the A 1166 C polymorphism of angiotensin II type 1 receptor gene (AGTR1) with blood pressure and central arterial stiffness in a population of hypertensive patients referred to hospital for further work-up. Methods One hundred and eighty-five patients, referred to our department from April 1998 to February 2002, were included. Blood pressure was measured by conventional and 24-h ambulatory methods, and arterial stiffness by carotid-femoral pulse wave velocity (PWV) determination. Genotyping for the AGTR1 A 1166 C polymorphism was performed by polymerase chain reaction. Results AGTR1 A 1166 C polymorphism was not associated with systolic or diastolic blood pressure, measured either by conventional (P = 0.89 and P = 0.67, respectively) or by 24-h ambulatory (P = 0.57 and P = 0.56, respectively) methods. Conversely, this polymorphism was significantly associated with PWV (P= 0.006) and had a dose-allele effect, PWV increasing with the number of A alleles (10.6 ± 2A m/s in CC, 11.9 ± 2.5 m/s in AC and 12.7 ± 2.7 m/s in AA patients, P= 0.002). Multiple regression analysis showed that A 1166 C polymorphism was still independently associated with PWV (P = 0.01) and was the third most important determinant of PWV after age (P< 0.0001) and 24-h mean blood pressure (P < 0.0001). Conclusion In our study population, central arterial stiffness assessed by PWV was significantly and independently associated with the A 1166 C polymorphism, increased PWV being associated with the presence of the A allele. Further investigations are required for identification of the underlying mechanisms.