Original Paper Cerebrovasc Dis 2003;16:217–223 DOI: 10.1159/000071119 Middle Cerebral Artery Stenosis in Type II Diabetic Chinese Patients Is Associated with Conventional Risk Factors but Not with Polymorphisms of the Renin-Angiotensin System Genes G. Neil Thomas a Jian Wen Lin a,c Wynnie W.M. Lam b Brian Tomlinson a Vincent Yeung a Juliana C.N. Chan a Ka Sing Wong a Departments of a Medicine and Therapeutics and b Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, Hong Kong SAR; c Department of Neurology, First Affiliated Hospital, Sun Yat-sen University of Medical Sciences, Guangzhou, China Received: July 8, 2002 Accepted: November 6, 2002 Ka Sing Wong Department of Medicine and Therapeutics Prince of Wales Hospital, Shatin, NT Hong Kong SAR (Hong Kong) Tel. +852 2632 3144, Fax +852 2637 3852, E-Mail ks-wong@cuhk.edu.hk ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 2003 S. Karger AG, Basel 1015–9770/03/0163–0217$19.50/0 Accessible online at: www.karger.com/ced Key Words Angiotensin-converting enzyme W Angiotensinogen W Angiotensin type 1 receptor W Blood pressure W Genetics W Glucose W Lipids W Middle cerebral artery stenosis W Renin-angiotensin system W Diabetes mellitus type II Abstract Background: Conventional and genetic risk factors have been reported to play a role in the pathogenesis of isch- aemic stroke, and differences may explain the heteroge- neity of disease presentation in different populations. In Chinese, middle cerebral artery (MCA) stenosis is the most commonly identified intracranial vascular lesion. The involvement of renin-angiotensin system (RAS) gene polymorphisms in this condition has not been determined. Objectives: To determine whether conven- tional and RAS genetic vascular risk factors are associat- ed with MCA stenosis, asymptomatic Chinese type II dia- betic patients with and without MCA stenosis matched for age, gender and diabetes duration were compared. Methods: Biochemical parameters and the genotype and allele frequencies of three RAS gene polymorphisms, the angiotensin-converting enzyme (ACE) insertion/deletion, angiotensinogen (AGT) M235T and angiotensin II type 1 receptor (AT 1 R) A1166C polymorphisms were then com- pared between 217 diabetics with and 490 matched dia- betic controls without MCA stenosis selected from 2,202 diabetics. Results: MCA stenosis was associated with significantly increased systolic blood pressure, LDL-cho- lesterol and albuminuria, yet diastolic blood pressure and glucose levels were lower. There was an increased prevalence of hypertension and use of blood pressure- lowering agents in the MCA stenosis patients. Albumin- uria was also more commonly found in these patients. Hypertensive status, systolic blood pressure and albu- minuria were strong, independent predictors of the pres- ence of MCA stenosis. No differences in the RAS poly- morphism distributions were observed between patients with and without MCA stenosis. Conclusions: In these asymptomatic type II diabetics, blood pressure indices and albuminuria, but not RAS gene polymorphism, were closely associated with MCA stenosis. Copyright © 2003 S. Karger AG, Basel