Polymorphisms in the angiotensinogen gene are associated with carotid intimal-medial thickening in females from a community-based population

Background: Polymorphisms within genes of the renin-angiotensin system have been associated with an increased risk of cardiovascular disease. We inves tigated the association of polymorphisms in the angiotensinogen (AGT) and a ngiotensin II receptor type I (AGTR1) genes with increased intima-media thi ckness (IMT) and the presence of plaques in carotid arteries. Methods: Subj ects (1111) from the Perth Carotid Ultrasound Disease Assessment Study (CUD AS) were genotyped for three polymorphisms: two in the promoter of the AGT gene, G-6A and A-20C; and one in the AGTR1 gene, A I 166C. Results: Using m ultivariate generalised linear models, the AGT-6A allele (P < 0.001) and th e AGT-20C allele (P < 0.03) were significantly associated with increased me an carotid IMT in females but not in males when adjusted for conventional r isk factors. The AGTR1 Al 166C polymorphism did not show any significant re lationship to mean IMT. Results suggest that the I allele of the angiotensi n converting enzyme insertion/deletion polymorphism may interact with the A GT-6G allele to increase mean carotid IMT in the population as a whole. Non e of the polymorphisms investigated were significantly associated with the presence of carotid plaques. Conclusion: This study shows that polymorphism s in the angiotensinogen gene are associated with an increased risk of caro tid intimal-medial wall thickening in females. (C) 2001 Elsevier Science Ir eland Ltd. All rights reserved.