Angiotensin-converting enzyme gene insertion/deletion polymorphism and carotid artery wall thickness in patients with peripheral arterial occlusive disease.

BACKGROUND: It has been suggested that the deletion polymorphism of the angiotensin converting enzyme (ACE) gene is linked to a high risk of cardiovascular disease. The relationship between the insertion/deletion (I/D) polymorphism of the ACE gene and the carotid intima-media thickness in patients with peripheral arterial occlusive disease is unknown. We tested the hypothesis that the early progression of atherosclerosis in the extracranial carotid arteries in patients with peripheral arterial disease is associated with a genetic predisposition. METHODS: This prospective trial included 98 patients who only had manifestations of arteriosclerotic disease in peripheral arterial vascular regions of the lower extremities (stable stage II PAOD). Maximal common carotid intima-media thickness (mIMT) was measured using high resolution B-mode ultrasonography. Determinations of ACE gene polymorphism were made using a polymerase chain reaction technique. Multivariate regression analysis was performed to assess the influence of ACE genotypes, ACE activity and vascular risk factors on intima-media thickness. RESULTS: There was no significant association between intima-media thickness and ACE gene polymorphism. History of symptomatic peripheral arterial disease without local or systemic progression exists in subjects with the II-genotype significantly longer than in subjects with the DD genotype (p=0.01). With the presence of an II-genotype, there was also a tendency towards a thinner intima-media thickness. We found significant correlations between intima-media thickness and age (p<0.0001), fasting serum insulin (p=0.001), and lipoprotein (a) (p=0.008). CONCLUSIONS: In the present study involving patients with stage II peripheral arterial occlusive disease, ACE gene polymorphism could not be identified as a determining marker for the development of intima-media thickening in the common carotid artery. However, it can be assumed that there is a reduced risk for the systemic progression of atherosclerosis in patients with the II genotype.