Relationship between vascular dementia and apolipoprotein E gene polymorphism: a case-control study

Jing SU; Fengjun LIU; Gaofeng CHANG

ABSTRACT

BACKGROUND:

Apolipoprotein E is one of the important plasma apolipoproteins with polymorphism and involved in lipid metabolism and cholesterol balance modulation, playing also a role in the normal growth and repair of the nervous system.

OBJECTIVE:

To analyze apolipoprotein E gene polymorphism in patients with vascular dementia (VaD) in comparison with patients with cerebral infarction (CI) patients and healthy controls, so as to elicit the relationship between apolipoprotein E gene polymorphism and VaD.

DESIGN:

Case-control study.

SETTING:

Department of Neurology, General Hospital of Jinan Military Area Command of Chinese PLA.

PARTICIPANTS:

The participants were recruited from the inpatients and outpatients with cerebrovascular diseases and healthy subjects for routine physical examination in the General Hospital of Jinan Military Area Command of Chinese PLA between August 2001 and October 2003, including 35 cases of VaD, 36 CI cases and 40 healthy controls.

METHODS:

Four milliliters of venous blood was collected from the elbow vein form all participants after fasting for 12 hours for detection of apolipoprotein E genotype using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Blood lipids and apolipoprotein contents were also examined.of triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDL-C), as well as apolipoprotein A and aoplipoprotein B.

RESULTS:

Data of 35 VaD 36 CI patients and 40 healthy controls were all VaD group and CI group had higher ε4 allele frequency were higher (22.86% and 22.22% vs 7.5%, respectively, P ＜ 0.05) but lower ε3 allele frequency (70% and 69.45% vs 86.25%, respectively, P ＜ 0.05); the frequencies of all alleles were basically comparable between VaD and CI groups er in E ε4 allele carriers [(5.85±L03), (4.73±0.29), (4.96±0.87) mmol/L, respectively] than in E ε2 [(3.91±0.87), (3.12±0.65), (3.06±0.33) mmol/L] and ε3 [(1.34±0.21), (1.00±0.28), (0.94±0.32) g/L] allele carriers in VaD group (P ＜ 0.05).

CONCLUSION:

Apolipoprotein E gene polymorphism is closely associated with the onset of VaD, for which ε4 allele might be a risk factor with similar impact in CI.