Effects of apolipoprotein E on dementia and aging in the Shanghai Survey of Dementia

Abstract

We investigated the status of the apolipoprotein E allele in 538 participants in the incidence phase of the ongoing Shanghai Survey of Dementia, including 103 demented subjects, 72 with mild cognitive impairment and 363 cognitively normal. The apo E epsilon 4 allele was present in 10.2% of control subjects and the allelic frequency did not change between ages 60 to 96 years. The apo E epsilon 4 allelic frequency was increased both in those wiht Alzheimer's disease (AD) (25.4%) and those with vascular dementia (VaD) (22.2%), but not in those with other dementing illnesses or the cognitively impaired. All of the subjects homozygous for apo E epsilon 4 were demented, three were diagnosed as having AD, and three met NINDS/AIREN criteria for VaD. The increased apo E epsilon 4 allelic frequency in clinically diagnosed VaD patients suggests that some of the infarcts are secondary to congophilic angiopathy. The adjusted odds ratio of developing AD in this community-derived study for persons with at least one apo E epsilon 4 allele was 4.1 (95% CI: 2.2, 7.7). Thus, the apo E epsilon 4 risk of developing AD in this Chinese cohort is similar to that in western community studies.

IL-6–174 G/C and ApoE Gene Polymorphisms in Alzheimer’s and Vascular Dementia Patients Attending the Cognitive Disorder Clinic of the All India Institute of Medical Sciences, New Delhi

“…Studies from Norway and Spain [7,8] have reported a higher frequency of the ε4 allele, while relatively lower percentages have been reported from Hungary and Iran [33,34]. Observations similar to our study have been reported in the past from Italy, Israel and China [9,10,11]. A recently conducted study involving neurodegenerative cases of dementia reported low frequency of the ε4 allele (15%) in the Indian population [35].…”

“…In the present study, the frequency of the ε4 allele was significantly higher in cases of VaD patients (17.4%) in comparison to the control group (p = 0.003). The percentage prevalence of the ε4 allele was similar to studies from Hungary and China [11,33]; however, one of the previous studies from our institute reported a relatively higher frequency of the ε4 allele in VaD patients [36]. The discrepancy could perhaps be due to the difference in samplings and/or relatively lower sample size.…”

“…In the literature, one can find both an association [8,9,10,11] and no association [35,36,37] with ApoE polymorphism. In the present study, the frequency of the ε4 allele was significantly higher in cases of VaD patients (17.4%) in comparison to the control group (p = 0.003).…”

“…ApoE has been widely studied and is a well-established risk factor for AD. Out of 3 alleles of ApoE, ε4 allele has been associated with an increased risk of AD [7,8,9,10,11]. ApoE ε4-targeted replacement in mice demonstrated a proinflammatory phenotype including increased iNOS mRNA synthesis and NO production, and higher proinflammatory cytokine production (TNF-α, IL-6, IL-12p40) in glial cell culture in comparison to the ApoE ε3-targeted replacement mice [12].…”

Apolipoprotein E Polymorphism and Age at Onset of Alzheimer’s Disease in a Quadriethnic Sample

“…These reports are unequivocal in Caucasian populations, but this association with risk of AD is not as strong or consistent in African American and Hispanic populations [5,7,19]. Reports examining East Asians are relatively limited, involving small samples, and therefore inconclusive [3,20,21,22]. …”