Impaired abdominal aortic wall integrity in elderly men carrying the angiotensin-converting enzyme D allele

Objective: A genetic polymorphism in the angiotensin-converting enzyme gene (ACE I/D polymorphism) has been associated with abdominal aortic aneurysm and a link between aortic aneurysm and aortic stiffness has been suggested. The aim of this study was to explore the links between ACE I/D polymorphism, circulating ACE, and abdominal aortic wall integrity as reflected by abdominal aortic wall stiffness. Material: The study population consisted of 406 subjects (212 men and 194 women) aged 70-88 years. Methods: The mechanical properties of the abdominal aorta were determined 3-4 cm proximal to the aortic bifurcation using a Wall Track System. ACE-genotype was determined by PCR followed by gel electrophoresis, and circulating ACE level was measured by ELISA. Results: Men carrying the ACE D allele had lower distensibility coefficient than II carriers (ID/DD 8.09 vs II 10.38, P=0.017). Multiple regression analyses showed additional associations between the ACE D allele and increased stiffness β as well as reduced cross-sectional compliance. Conclusion: This study showed that men carrying the ACE D allele have stiffer abdominal aortas compared to II carriers. Deranged abdominal aortic stiffness indicates impaired vessel wall integrity, which along with other local predisposing factors, may be of importance in aneurysmal disease.