The relationship of plasma homocysteine level and apolipoprotein E gene polymorphism with Alzheimer's disease / 中华老年医学杂志

ABSTRACT

Objective To investigate the correlations of plasma homocysteine(Hcy)level and apolipoprotein E gene polymorphism with Alzheimer' s disease(AD)and mild cognitive impairment (MCI).Methods A case-control study in 66 AD patients(AD group),64 MCI patients(MCI group) and 54 healthy controls(control group)was conducted.Plasma Hcy level and ApoE polymorphism were determined and analyzed.Results Plasma Hcy levels were significantly higher in AD and MCI groups than in control subjects(both P＜0.001).AD patients also showed increased plasma Hcy levels as compared with MCI patients(P＜0.001).Logistic regression analysis indicated that the increased plasma Hcy level was a risk factor for AD and MCI(OR＝ 1.435 and 1.312,both P＜0.001).ApoE ε3/3 was the most common genotype in AD,MCI and control groups,and ε3/4 and ε4/4 genotypes were more common in AD group and MCI group than in control group(both P＜0.05).The ε4 allele frequency of ApoE was 24.2％ and 23.4％ in AD or MCI group respectively,and 6.5％ in control group(AD or MCI vs.control,P＜0.05).The analysis by multiplicative interaction model showed that the odd ratio for MCI was 23.3 in patients with only hyperhomocysteinemia(Hhcy,Hcy＞ 15 μmol/L),12.6 in patients with carrying ε4 allele,and 46.7 in patients with both Hhcy and carrying ε4 allele,which indicated that there was interaction between hyperhomocysteinemia and carrying e4 allele.Conclusions Hyperhomocysteinemia and ApoE ε4 allele are correlated with dementia and also have additive interactions.