Geographic and Sex Difference in the Distribution
of Intracranial Atherosclerosis in China
Yuehua Pu, MD*; Liping Liu, MD*; Yilong Wang, MD; Xinying Zou, MD, PhD; Yuesong Pan, MD;
Yannie Soo, MD; Thomas Leung, MD; Xingquan Zhao, MD; Ka Sing Wong, MD;
Yongjun Wang, MD; on behalf of the Chinese IntraCranial AtheroSclerosis (CICAS) Study Group
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Background and Purpose—Geographic variation and sex difference in the distribution of intracranial atherosclerosis
(ICAS) have not been fully discussed before in Chinese patients with cerebral ischemia. We performed this study with
the aim to investigate geographic and sex difference in the distribution of ICAS in China.
Methods—In this prospective multicenter study, we evaluated 2864 consecutive patients who experienced an acute cerebral
ischemia within 7 days of symptom onset in 22 hospitals in China. All the inclusive patients underwent 3-dimensional
time-of-flight MR angiography and duplex color Doppler ultrasound or contrast-enhanced MR angiography to document
the presence of intracranial or extracranial stenosis. Intracranial large-artery atherosclerosis was defined as ≥50% diameter
reduction on MR angiography.
Results—The proportion of patients with ICAS was significantly higher in north China than in south China (50.22% versus
41.88%; P<0.0001). Patients in the north were likely to consume more alcohol and smoke more cigarettes and had
significantly higher proportion of diabetes mellitus, family history of stroke, history of cerebral ischemia, heart disease,
and higher body mass index. In patients aged >63 years, the percentage of ICAS in women was notably higher than in men
(51.51% versus 45.40%; P=0.028). In elderly patients, women had higher proportion of diabetes mellitus, hypertension,
hyperlipidemia, and heart disease than men.
Conclusions—There exists geographic and sex difference in the distribution of symptomatic ICAS in China. Public health
measures should strengthen improving social determinants of health and risk factor prevention/control in high-risk
populations for decreasing stroke risk. (Stroke. 2013;44:2109-2114.)
Key Words: geographic
■
ischemic
■
intracranial stenosis
G
eographic variation in stroke incidence, mortality, and
prevalence has been observed in some regions. In United
States, higher stroke mortality has long been commonly found
among residents of the southeastern states (the stroke belt
region).1 Differences in socioeconomic status, risk factors, and
prevalence of common chronic diseases may explain the regional
differences.2 In China, the Sino International collaborative World
Health Organization Monitoring of Trends and Determinants
in Cardiovascular Disease (MONICA) project supported the
north–south gradient, with the highest stroke incidence in
Heilongjiang province and the lowest incidences in Anhui and
Fujian provinces.3 Large-artery atherosclerosis is a very common
subtype of ischemic stroke. Intracranial atherosclerosis (ICAS)
is the most common vascular lesions in China.4,5 However, until
now, geographic difference in the distribution of ICAS in China,
even in the world, has not been reported.
In recent years, sex-specific data on stroke incidence,
prevalence, subtypes, severity, and case fatality have become
■
sex differences
■
stroke
available from different parts of the world. Stroke is more
common among men, but women are more severely ill.6 Data
regarding ICAS are quite meager and remain controversial.
Several studies have shown female predominance in ICAS,7
whereas others have reported that men are more likely to have
ICAS than women.8 A clinical study in Chinese subjects,9
mainly in asymptomatic subjects, also reported a male predominance in ICAS. An autopsy study showed that the sex
difference in ICAS was influenced by age. From the fourth to
sixth decades of life, the percentage of women with no cerebral atherosclerosis was higher than men, but at >65 years of
age the frequency of atherosclerotic lesions was the same in
2 sexes.10
Above all, geographic variation and sex difference in the
distribution of ICAS have not been fully discussed before.
So, we performed this study with the aim to investigate
­geographic and sex difference in the distribution of ICAS
in China.
Received March 17, 2013; final revision received April 16, 2013; accepted April 30, 2013.
From the Department of Neurology, Beijing Tiantan Hospital of Capital Medical University, Beijing, China (Y.P., L.L., Y.W., Y.P., X.Z., Y.W.); and
Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China (X.Z., Y.S., T.L., K.S.W.).
*Drs Pu and Liu are co-first authors.
Miguel A. Perez-Pinzon, PhD, was the guest editor for this article.
Correspondence to Yongjun Wang, MD, Department of Neurology, Beijing Tiantan Hospital of Capital Medical University, No. 6 Tiantan Xili, Dongcheng
District, Beijing, China. E-mail [email protected]
© 2013 American Heart Association, Inc.
Stroke is available at http://stroke.ahajournals.org
DOI: 10.1161/STROKEAHA.113.001522
2109
2110 Stroke August 2013
Methods
Study Design and Patient Eligibility
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The Chinese IntraCranial AtheroSclerosis Study is a prospective,
multicenter, cohort, hospital-based study. Twenty-two general hospitals covering a wide geographic area in China participated. (The
hospital list is showed in the Appendix.) The study was approved by
the institutional review board of the participating hospitals. In addition, all participants provided written informed consent for study
participation.
Data were prospectively collected from consecutive patients with
cerebral ischemia, including ischemic stroke and transient ischemic
attack, using a standardized case report form. Inclusion criteria included onset of symptom within 7 days and age between 18 and 80
years. We excluded patients who were clinically unstable or required
close monitoring or were moribund, were disabled before admission
(modified Rankin scale >2), were physically or subjectively unable
to comply with MR examination, or had severe comorbidity. We excluded patients with cardioembolic risk (including atrial fibrillation,
valvular heart disease, postcardiac valve replacement, and so on) to
avoid the inclusion of vascular occlusion because of cardioembolism.
On admission, baseline data, including age, sex, medical history,
and physical examination, were collected. All patients underwent
detailed clinical evaluation, including laboratory tests, brain MR scan,
3-dimensional (3D) time-of-flight MR angiography (MRA), duplex
color Doppler ultrasound, or contrast-enhanced MRA. Intracranial
vessels were judged by 3D time-of-flight MRA, and extracranial
carotid vessels were examined by duplex color Doppler ultrasound
or contrast-enhanced MRA. According to the Huai River–Qinling
Mountains line, we divided the participants into northern part and
southern part.
From October 2007 to June 2009, 3580 patients were registered.
We excluded 325 patients with risk of cardioembolism. In addition,
we excluded 391 patients because of incomplete cerebrovascular
workup, such as MRI/MRA examination. We analyzed the remaining
cohort of 2864 consecutive patients.
Definition of Risk Factors
The clinical information included age, sex, hypertension (defined
as a history of hypertension or required regular treatment with antihypertensive agent before admission or diagnosed at discharge),
diabetes mellitus (defined as a history of diabetes mellitus or being
treated for diabetes mellitus or glycosylated hemoglobin ≥7% or diagnosed at discharge), hyperlipidemia (defined as low-density lipoprotein cholesterol 2.6 mmol/L at the time of admission or a history
Table 1. Baseline Characteristics by Geography and Sex
By Geography
Characteristics
Sex (men)
North (n=1627)
455 (27.97)
Age*, y
60.21±11.14
Diabetes mellitus
594 (36.51)
South (n=1237)
By Sex (Patients >63 y)
P Value
Women (n=530)
465 (37.59)
<0.0001
64.14±10.98
<0.0001
71.91±4.67
397 (32.09)
0.0139
240 (45.28)
Men (n=826)
71.62±4.67
267 (32.32)
P Value
0.2669
<0.0001
Hypertension
1267 (77.87)
971 (78.50)
0.6895
454 (85.66)
648 (78.45)
0.0009
Hyperlipidemia
1255 (77.14)
918 (74.21)
0.0700
413 (77.92)
594 (71.91)
0.0135
Family history of stroke
232 (14.26)
64 (5.17)
<0.0001
32 (6.04)
60 (7.26)
Current smoker
706 (43.39)
343 (27.73)
<0.0001
29 (5.47)
289 (34.99)
0.3810
<0.0001
Heavy drinker
105 (6.45)
37 (2.99)
<0.0001
0 (0.00)
36 (4.36)
<0.0001
Hyperhomocystinemia
689 (42.35)
61 (4.93)
<0.0001
91 (17.17)
226 (27.36)
<0.0001
1214 (74.62)
804 (65.00)
<0.0001
379 (71.51)
659 (79.78)
0.0005
33 (2.03)
21 (1.70)
0.5193
6 (1.13)
19 (2.30)
0.1187
161 (9.90)
67 (5.42)
<0.0001
78 (14.72)
69 (8.35)
0.0002
16 (0.98)
5 (0.40)
0.0719
5 (0.94)
3 (0.36)
0.1734
25.14±3.17
23.8±2.98
<0.0001
24.14±3.63
24.12±3.07
History of cerebral ischemia
History of hemorrhagic stroke
Heart disease
Peripheral angiopathy
BMI*, kg/m2
NIHSS†
3 (1–7)
4 (2–6)
0.0095
4 (2–7)
4 (2–7)
0.9185
0.0720
SBP at admission*, mm Hg
150.84±23.25
157.65±23.81
<0.0001
157.69±23.12
153.56±22.79
0.0012
DBP at admission*, mm Hg
89.66±13.82
88.16±13.16
0.0032
86.59±12.03
85.97±11.85
0.3566
PP*, mm Hg
61.18±18.22
69.5±18.83
<0.0001
71.11±20.06
67.59±18.06
0.0011
110.06±15.29
111.32±15.03
0.0274
110.29±13.61
108.5±13.94
0.0207
Fasting blood glucose*,
mmol/L
6.11±2.35
6.44±2.7
0.0010
6.82±3.1
6.02±2.2
MBP*, mm Hg
<0.0001
SCRP†, mg/L
2.6 (0.9–7.2)
2.63 (1–6.33)
0.3195
2.93 (1.16–7.8)
3.16 (1.14–9.16)
Glycohemoglobin*, %
6.48±1.73
6.59±1.87
0.2429
6.83±1.81
6.31±1.52
<0.0001
0.5006
TG*, mmol/L
1.81±1.33
1.88±1.19
0.1410
1.59 (1.2–2.27)
1.28 (0.98–1.8)
<0.0001
TC*, mmol/L
4.61±1.14
4.86±1.25
<0.0001
4.95±1.26
4.56±1.11
<0.0001
HDL*, mmol/L
1.15±0.3
1.19±0.37
0.0022
1.25±0.33
1.15±0.34
<0.0001
LDL*, mmol/L
2.85±0.95
2.97±0.98
0.0019
3.04±0.99
2.82±0.97
0.0001
BMI indicates body mass index; DBP, diastolic blood pressure; ICAS, intracranial atherosclerosis; HDL, high-density lipoprotein cholesterol; LDL, low-density lipoprotein
cholesterol; MBP, mean arterial pressure; NIHSS, National Institutes of Health Stroke Scale; PP, pulse pressure; SBP, systolic blood pressure; SCRP, serum C-reactive
protein; TC, total lipoprotein cholesterol; and TG, triglyceride.
*Continuous variables with normal distribution expressed as mean±SD.
†Continuous variables with non-normal distribution expressed as interquartile range; other values are expressed as n (%).
Pu et al Geographic and Sex Difference of ICAS in China 2111
of hyperlipidemia or received lipid-lowering treatments or diagnosed
at discharge), a history of cerebral ischemia (including a history of
ischemic stroke and transient ischemic attack or evidence of old infarct on MRI), a history of hemorrhagic stroke (including intracerebral hemorrhage and subarachnoid hemorrhage), and heart disease
(defined as a known history of myocardial infarction, angina pectoris,
and congestive heart failure). In addition, current smoker (defined as
a patient who had smoked continuously for 6 months ≥1 cigarette a
day), heavy drinker (drinking >2 U/d on average for men or >1 U/d on
average for women), and hyperhomocystinemia (serum level of total
homocysteine ≥15 μmol/L) were noted.
Image Analysis/Interpretation
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All patients underwent conventional MRI on a 3.0 or 1.5T MR scanner, including a sequence of 3D time-of-flight MRA. Other MR
sequences, such as T2-/T1-weighted imaging, fluid-attenuated inversion recovery sequences, and diffusion-weighted imaging (DWI),
were also performed. All MRI/MRA images were stored in digital
format and were read centrally by 2 readers (X.Y. Zou and Y. Soo)
who were blinded to the subjects’ clinical information or outcome.
Disagreements of >10% degree of stenosis were resolved by a third
reader who decided the final value.
Degree of intracranial stenosis on MRA was calculated using the
published method for the Warfarin–Aspirin Symptomatic Intracranial
Disease Study.11 All measurements were made with Wiha DigiMax
Digital Calipers 6′ (Germany), with a resolution of 0.01 to 0.03 mm
for 0 to 100 mm. We assessed the following arterial segments: bilateral intracranial internal carotid artery, anterior cerebral artery A1/A2,
middle cerebral artery M1/M2, posterior cerebral artery P1/P2, and
basilar artery. For the internal carotid artery, an intracranial location
was defined as distal to the ophthalmic artery. According to the severity of stenosis, we classified the patients into 4 groups: <50% or no
stenosis, 50% to 69% stenosis, 70% to 99% stenosis, and occlusion
groups. We regarded focal flow void found on MRA with distal filling
as severe stenosis (70%–99%).12 Absence of distal filling on MRA
would be regarded as 100% occlusion. According to the distribution
of stenosis, we categorized vessels with >50% stenosis or occlusion
as presence of intracranial stenosis, extracranial stenosis, or tandem
group (both intracranial and extracranial stenosis). The extracranial
part of internal carotid artery was estimated with ultrasonographic
examination according to the published diagnostic criteria13 or by
contrast-enhanced MRA.
Statistical Analysis
All analyses were performed with SAS software version 9.1 (SAS
Institute Inc, Cary, NC). Continuous variables were summarized as
median (interquartile range) or mean (SD). Categorical variables,
such as sex, vascular risk factors, and location of stenotic arteries, were presented as percentages. Independent samples t test or
Wilcoxon test was used for comparison of continuous variables, and
χ2 test or Fisher exact test was used for comparison of categorical
variables. When the incidence of ICAS was compared, we used logistic regression to adjust for age and sex. All tests were 2-sided, with a
significance level fixed at 5%.
Results
Of the participants included in these analyses, the mean age at
admission for index stroke was 61.9±11.2 years (19–80 years);
1944 (67.9%) were men, and 1627 (56.8%) were from northern
part of china. In patients aged ≤63 years, 1118 (74.1%) were
men, and in patients aged >63 years, 826 (60.9%) were men.
Patients with ICAS were significantly higher in northern
part than in the southern part (50.22% versus 41.88%;
odds ratio, 1.400; 95% confidence interval, 1.206–1.625;
P<0.0001); after adjusted by age and sex, the difference
was still remarkable (P<0.0001; odds ratio, 1.467; 95%
Figure. Percentage of intracranial atherosclerosis (ICAS) and
extracranial atherosclerosis (ECAS) in different age stages
between men and women. Horizontal axis represents age of
each stage. Vertical axis represents the percentage of ICAS or
ECAS. Lines in the upper part represent the percentage of ICAS
in women (□) and men (◊). Lines in the lower part represent the
percentage of ECAS in women (×) and men (Δ). Values in the
table below graph represent the points on each line.
confidence interval, 1.260–1.708). The difference in baseline
characteristics by geography and sex is shown in Table 1.
Patients in southern China were older than the patients in
northern China, with higher proportion of men (37.59%
versus 27.97%; P<0.0001). Patients in the north were more
likely to consume alcohol and cigarettes and had significantly
higher proportion of diabetes mellitus, family history of
stroke, history of cerebral ischemia, heart disease, and higher
body mass index. On admission, southern patients had higher
National Institutes of Health Stroke Scale, systolic blood
pressure, pulse pressure, mean arterial pressure, fasting
blood glucose, total lipoprotein cholesterol, and high-density
and low-density lipoprotein cholesterol levels. In addition,
northern patients were likely to have cerebral atherosclerotic
lesions, especially in extracranial, and both intracranial and
extracranial lesions. Northern patients had significantly higher
percentage of multiple intracranial atherosclerosis (23.91%
versus 15.68%; P<0.0001) and occlusive lesion (30.12%
versus 20.45%) than the southern patients.
In total, the distribution of ICAS between men and
women had no significant difference (46.09% versus
47.72%; P=0.4151), nor did the patients aged ≤63 years.
For patients aged >63 years, the percentage of ICAS in
women was notably higher than in men (51.51% versus
45.40%; P=0.028). Regarding the distribution of extracranial
atherosclerosis, men had significantly higher percentage than
women (15.90% versus 10.00%; P<0.0001). The percentage
of ICAS and extracranial atherosclerosis in different age
stages between men and women is shown in the Figure. In
elderly patients, women had higher proportion of diabetes
mellitus, hypertension, hyperlipidemia, and heart disease
than men. Men were more likely to consume alcohol and
smoke cigarettes and had significantly higher proportion of
hyperhomocystinemia and history of cerebral ischemia than
women. On admission, women had higher systolic blood
pressure, pulse pressure, mean arterial pressure, fasting blood
glucose, glycohemoglobin, triglyceride, total lipoprotein
2112 Stroke August 2013
Table 2. Geographic and Sex Difference of ICAS
By Geography
Distribution of ICAS
North (n=1627)
South (n=1237)
Cerebral atherosclerosis
By Sex (Patients Aged >63 y)
P Value
Women (n=530)
Men (n=826)
<0.0001
None
712 (43.76)
676 (54.65)
238 (44.91)
387 (46.85)
Intracranial only
610 (37.49)
464 (37.51)
233 (43.96)
282 (34.14)
Extracranial only
98 (6.02)
43 (3.48)
19 (3.58)
64 (7.75)
Intra- and extracranial
207 (12.72)
54 (4.37)
40 (7.55)
93 (11.26)
Multiple ICAS*
389 (23.91)
194 (15.68)
131 (24.72)
166 (20.10)
None
810 (49.78)
719 (58.12)
257 (48.49)
451 (54.60)
Anterior
393 (24.15)
277 (22.39)
109 (20.57)
179 (21.67)
Posterior
197 (12.11)
137 (11.08)
70 (13.21)
101 (12.23)
Anterior and posterior
227 (13.95)
104 (8.41)
94 (17.74)
95 (11.50)
Distribution of ICAS1†
<0.0001
P Value
<0.0001
<0.0001
0.0447
0.0083
Distribution of ICAS2
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ACA
153 (9.40)
66 (5.34)
<0.0001
58 (10.94)
62 (7.51)
0.0297
MCA
512 (31.47)
336 (27.16)
0.0124
170 (32.08)
234 (28.33)
0.1411
PCA
337 (20.71)
196 (15.84)
0.0009
133 (25.09)
156 (18.89)
0.0065
BA
126 (7.74)
55 (4.45)
0.0003
43 (8.11)
56 (6.78)
0.3570
Intracranial ICA
119(7.31)
56 (4.53)
0.0020
26 (4.91)
49(5.93)
0.4197
0.0276
Severity of ICAS‡
<0.0001
None or <50%
810 (49.78)
719 (58.12)
257 (48.49)
451 (54.60)
50%−69%
201 (12.35)
139 (11.24)
76 (14.34)
98 (11.86)
70%−99%
126 (7.74)
126 (10.19)
71 (13.40)
100%
490 (30.12)
253 (20.45)
126 (23.77)
6 (9.20)
201 (24.33)
Values are expressed as n (%). ACA indicates anterior cerebral artery; BA, basilar artery; ICA, internal carotid artery; ICAS, intracranial atherosclerosis; MCA, middle
cerebral artery; PCA, posterior cerebral artery.
*≥2 stenosis in any arterial segments.
†None: no or <50% stenosis in any arterial segments; anterior: stenosis in anterior circulation; posterior: stenosis in posterior circulation; anterior and posterior:
stenosis in both anterior and posterior circulation.
‡Rate of stenosis. If stenosis was multiple, the more serious stenosis was recorded.
cholesterol, and high-density and low-density lipoprotein
cholesterol levels. In addition, female patients were likely
to have intracranial atherosclerotic lesions (43.96 versus
34.14%), yet male patients were likely to have extracranial
and both intracranial and extracranial lesions. Multiple
intracranial atherosclerotic lesions were more common in
women (24.72% versus 20.10%; P=0.0447).
Discussion
Geographic Difference in ICAS
Our data indicate that distribution of ICAS has geographic
variation in China, with higher rates in the north and lower
rates in the south. Furthermore, northern patients are more
likely to have both intracranial and extracranial atherosclerotic lesions, multiple intracranial atherosclerosis,
and occlusive lesion than the southern patients. Northern
patients have more risk factors of atherosclerosis, such as
diabetes mellitus, hyperlipidemia, family history of stroke,
smoking, heavy drinking, hyperhomocystinemia, and overweight, which help to explain the difference (Table 2).
People in the north and south have different lifestyle, food
habits, and environment. People in the north are more likely
to smoke cigarettes, drink alcohol, and consume fatty foods
and salt. This may increase the risk of having hypertension,
diabetes mellitus, hyperlipidemia, obesity, and so on. Previous
studies in China have documented regional variations in the
prevalence of hypertension,14 diabetes mellitus,15 hyperlipidemia,16 and obesity.17 Genetic polymorphism is another
influential factor for these differences. Hu et al18 found that
positive correlation existed between the e4 allele frequency
distribution and a northern latitude (r=0.586; P=0.008) in
China. Many studies have shown that ICAS is associated with
lipid disorder,19 hypercholesterolemia,20 tobacco use,21,22 and
diabetes mellitus.19,23,24 Diabetes mellitus, as well as a history
of ischemic heart disease, was found to be more significantly
prevalent in patients with combined extracranial internal
carotid artery and intracranial stenosis.25 The results of our
study improve the understanding of the various factors that
affect patients with cerebral ischemia in different regions of
China. Primary prevention (such as improved lifestyle and
control risk factors) should be strengthened to reduce the incidence of ICAS in the northern area.
Sex Difference in ICAS
For the entire sample, there was no difference in the distribution of ICAS between men and women. But in patients aged
Pu et al Geographic and Sex Difference of ICAS in China 2113
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>63 years, the difference was significant. Multiple intracranial atherosclerotic lesions were also very common in women
aged >63 years. Men were likely to have extracranial atherosclerosis, which has been proved in other population.26 These
results are similar to those of Flora et al,10 who found that
the frequency of cerebral atherosclerosis increases more rapidly in women after the sixth decade. In our study, elderly
women have more diabetes mellitus, hypertension, hyperlipidemia, and history of heart disease, which can help explain
the difference. Our results were not unexpected. Among premenopausal and early perimenopausal women, hormones,
particularly low sex hormone–binding globulin and high free
androgen index, are related to elevated cardiovascular risk
factors (higher insulin, glucose, hemostatic and inflammatory markers, and adverse lipids).27 Sex difference was also
found on prevalence of diabetes mellitus. The China National
Diabetes and Metabolic Disorders Study showed that female
patients aged >60 years had higher prevalence of diabetes
mellitus than men.28
Zhang); The First Affiliated Hospital of Jinan University,
Guangzhou, Guangdong (Anding Xu); Guangzhou City
Peoples First Hospital, Guangzhou, Guangdong (Xiaoping
Pan); Guangdong Hospital of Traditional Chinese Medicine,
Guangzhou, Guangdong (Yefeng Cai); Handan Central
Hospital, Handan, Heibei (Juntao Li); Handan First People’s
Hospital, Handan, Heibei (Yiping Wu and Jie Lin); Qingdao
Municipal Hospital, Qingdao, Shandong (Chengming Xing);
The First Affiliated Hospital of Zhengzhou University,
Zhengzhou, Henan (Yuming Xu); The First Affiliated Hospital
of Zhejiang University, Hangzhou, Zhejiang (Benyan Luo);
The First Affiliated Hospital of Wenzhou Medical College
(the first provincial Wenzhou Hospital of Zhejiang), Wenzhou,
Zhejiang (Rongyuan Zheng and Zhao Han); Affiliated Kailuan
Hospital, North China Coal Medical College, Tangshan,
Hebei (Xiaodong Yuan); The First Affiliated Hospital of
Beifang Medical College, Zhangjiakou, Hebei (Wanlin Cui
and Yuan Zou); Shijiazhuang Center Hospital, Shijiazhuang,
Hebei (Heli Yan).‍
Strengths and Limitations
These are the first data about geographic and sex difference
of ICAS in Chinese patients with cerebral ischemia. The
results are from a multicenter, large-sample, consecutive
cohort study that uses MRA as the screening tool for ICAS.
It decreases the diagnostic error for ICAS. As to the limitations, this study was hospital based, and the participating hospitals were all upper first-class hospitals, and some degree of
sampling bias existed. It is difficult to distinguish occlusion
caused by embolism of uncertain source from atherosclerotic
occlusion on MRA.
Conclusions
There exists geographic and sex difference in the distribution
of symptomatic ICAS in China. The proportion of ICAS is
higher in the north, and northern patients are more likely to
have multiple intracranial atherosclerosis and occlusive lesion
than the southern patients. Female patients aged >63 years
have higher percentage of ICAS, whereas men were likely to
have extracranial atherosclerosis. Difference in risk factors
helps to explain the variation in ICAS prevalence. To decrease
the risk of stroke, the government should support early implementation of cerebrovascular examination in high-risk populations; public health measures should strengthen improving
social determinants of health and risk factor prevention/control in those with high risk of ICAS.
Appendix
Beijing Tongren Hospital of Capital Medical University,
Beijing (Xiaojun Zhang); Shanghai Jiaotong University
Affiliated Sixth People’s Hospital, Shanghai (Xiaojiang SUN);
Shanghai Pudong New Area People’s Hospital, Shanghai
(Qingke Bai); Tianjin Huanhu Hosptial, Tianjin (Lan Yu);
Shanxi Provincial People’s Hospital, Xi’an, Shanxi (Minxia
Guo); The First Affiliated Hospital of Xiamen University,
Xiamen, Fujian (Qilin Ma); Xiangya Hospital Central-South
University, Changsha, Hunan (Bo Xiao and Le Zhang);
Chengdu No.3 People’s Hospital, Chengdu, Sichuan (Zhong
Sources of Funding
This study was funded by the Ministry of Science and Technology
and the Ministry of Health of the People’s Republic of China, grant
no. National S&T Major Project of China (2008ZX09312-008)
and State Key Development Program of Basic Research of China
(2009CB521905) and, in part, by the S.H. Ho Cardiovascular Disease
and Stroke Center of the Chinese University of Hong Kong.
Disclosures
None.
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Geographic and Sex Difference in the Distribution of Intracranial Atherosclerosis in China
Yuehua Pu, Liping Liu, Yilong Wang, Xinying Zou, Yuesong Pan, Yannie Soo, Thomas Leung,
Xingquan Zhao, Ka Sing Wong and Yongjun Wang
on behalf of the Chinese IntraCranial AtheroSclerosis (CICAS) Study Group
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Stroke. 2013;44:2109-2114; originally published online June 11, 2013;
doi: 10.1161/STROKEAHA.113.001522
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