Pentanucleotide TTTTA repeat polymorphism of apolipoprotein(a) gene and plasma lipoprotein(a) are associated with ischemic and hemorrhagic stroke in Chinese: a multicenter case-control study in China.
OBJECTIVE
It is still inconclusive whether high plasma lipoprotein(a) [Lp(a)] level is a risk factor for stroke. Small sample size and different ethnic groups and methodologies might be contributors to the conflicts in study results. The purpose of the present study was to investigate the association between plasma Lp(a) levels, pentanucleotide TTTTA repeat (PNTR) polymorphism of the apolipoprotein(a) [apo(a)] gene, and Chinese stroke in a case-control study.


METHODS
We recruited 1825 cases with stroke (44.3% cerebral atherothrombosis, 28.3% lacunar infarction, and 27.3% intracerebral hemorrhage) and 1817 controls from 7 centers in China. Lp(a) concentrations were quantified by enzyme-linked immunosorbent assay. The PNTR polymorphism of the apo(a) gene was determined by polymerase chain reaction-polyacrylamide gel electrophoresis. Conditional multivariate logistic regression analysis was used to identify independent risk factors for stroke and its subtypes.


RESULTS
Lp(a) levels were significantly higher in cases than in controls (median, 28.5 versus 23.1 mg/dL; P<0.001), leading to a 1.97-fold (95% CI, 1.64 to 2.37) increase in risk for overall stroke, 2.0-fold (95% CI, 1.59 to 2.52) increase for atherothrombotic type, 2.05-fold increase (95% CI, 1.59 to 2.63) for lacunar type, and 1.64-fold increase (95% CI, 1.21 to 2.21) for hemorrhagic type. The number of PNTR negatively correlated with Lp(a) levels. Low-number repeats (sum of both alleles <16) of apo(a) PNTR were associated with both atherothrombotic stroke (odds ratio, 1.41; 95% CI, 1.04 to 1.91) and hemorrhagic stroke (odds ratio, 1.62; 95% CI, 1.09 to 2.37).


CONCLUSIONS
Our results indicate for the first time that low numbers of apo(a) PNTR and plasma Lp(a) levels are independently associated with both ischemic and hemorrhagic stroke in Chinese.
Sun
Li
L
Sino-German Laboratory for Molecular Medicine and Center for Molecular Cardiology, Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Li
Zhaohui
Z
Zhang
Hongye
H
Ma
Aiqun
A
Liao
Yuhua
Y
Wang
Daowen
D
Zhao
Bingrang
B
Zhu
Zhiming
Z
Zhao
Jizong
J
Zhang
Zhen
Z
Wang
Wei
W
Hui
Rutai
R
D020121:5' Untranslated Regions / Q000235:genetics; D000328:Adult; D000368:Aged; D000483:Alleles; D001053:Apolipoproteins / Q000235:genetics*; D053241:Apoprotein(a); D002545:Brain Ischemia / Q000097:blood / Q000453:epidemiology; D016022:Case-Control Studies; D002543:Cerebral Hemorrhage / Q000097:blood / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008055:Lipids / Q000097:blood; D017270:Lipoprotein(a) / Q000097:blood* / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000453:epidemiology*
D020121:5' Untranslated Regions; D001053:Apolipoproteins; D008055:Lipids; D017270:Lipoprotein(a); D053241:Apoprotein(a)