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.
BACKGROUND
Conventional and genetic risk factors have been reported to play a role in the pathogenesis of ischaemic stroke, and differences may explain the heterogeneity 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.


OBJECTIVE
To determine whether conventional and RAS genetic vascular risk factors are associated with MCA stenosis, asymptomatic Chinese type II diabetic 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 compared between 217 diabetics with and 490 matched diabetic controls without MCA stenosis selected from 2,202 diabetics.


RESULTS
MCA stenosis was associated with significantly increased systolic blood pressure, LDL-cholesterol 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. Albuminuria was also more commonly found in these patients. Hypertensive status, systolic blood pressure and albuminuria were strong, independent predictors of the presence of MCA stenosis. No differences in the RAS polymorphism 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.
Thomas
G Neil
GN
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, Hong Kong SAR.
Lin
Jian Wen
JW
Lam
Wynnie W M
WW
Tomlinson
Brian
B
Yeung
Vincent
V
Chan
Juliana C N
JC
Wong
Ka Sing
KS
D000368:Aged; D044466:Asian People / Q000235:genetics*; D002539:Cerebral Arterial Diseases / Q000000981:diagnostic imaging / Q000209:etiology* / Q000235:genetics*; D002681:China; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000000981:diagnostic imaging / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012084:Renin-Angiotensin System / Q000235:genetics*; D012307:Risk Factors; D017585:Ultrasonography, Doppler, Transcranial