The Association between Apolipoprotein E Gene Polymorphism and Mild Cognitive Impairment among Different Ethnic Minority Groups in China

Abstract

The association, in different ethnic groups, of apolipoprotein E (apoE) gene polymorphism with mild cognitive impairment (MCI) has been unclear. Few studies have examined the association in Chinese minorities. The current study explores the association between apoE gene polymorphism and MCI in one of the biggest ethnic groups—the Hui—and compares it with the Han. The Minimental State Exam, Activities of Daily Living Scale, and Geriatric Depression Scale were administered to 306 ethnic Hui and 618 ethnic Han people aged ≥55 years. ApoE genotypes were determined using the high resolution melting curve method. The distribution of the apoE genotype and the frequency of alleles ε2, ε3, and ε4 were similar in the Hui and Han groups. In analyses adjusted for age, gender, and education level, the ε4 allele was a risk factor for MCI in both the Hui group (OR = 2.61, 95% CI: 1.02–6.66) and the Han group (OR = 2.36, 95% CI: 1.19–4.67), but the apoE ε2 allele was protective for MCI only in the Han group (OR = 0.48, 95% CI: 0.38–0.88). The association of some apoE genotypes with MCI may differ in different ethnic groups in China. Further studies are needed to explore this effect among different populations.

Associations between APOE polymorphisms and seven diseases with cognitive impairment including Alzheimer’s disease, frontotemporal dementia, and dementia with Lewy bodies in southeast China

“…We found that ε4 increased the risk of MCI in a dose-dependent manner, which was also in accordance with previous reports in both White and Chinese populations ( Borenstein et al , 2010 ; Boyle et al , 2010 ; Albert et al , 2014 ; Wang et al , 2014 ). In contrast, the APOE ε2 allele appeared to confer cognitive benefits in the White population ( Blacker et al , 2007 ; Bonner-Jackson et al , 2012 ).…”

Insulin resistance and cognitive dysfunction

“…The ApoE ε4 allele polymorphism is an independent risk factor for MCI, and cognitive level in ε4 carriers is lower than noncarriers [103]. ApoE ε4 incidence in MCI patients is significantly higher than the normal population [103]. Risk ratio of late-onset AD in ApoE ε4 carriers is approximately three times higher than noncarriers [104].…”

“…ApoE protein, Aβ, and tau protein interact in a specific way, which may be the biological basis for ApoE effect on dementia development [102]. The ApoE ε4 allele polymorphism is an independent risk factor for MCI, and cognitive level in ε4 carriers is lower than noncarriers [103]. ApoE ε4 incidence in MCI patients is significantly higher than the normal population [103].…”

Population Difference in the Associations of KLOTH Promoter Methylation with Mild Cognitive Impairment in Xinjiang Uygur and Han Populations

“…Predictive risk factors for MCI in non-Hispanic cohorts were not associated with MCI in Mexican Americans [ 52 ], who were more likely to be possessed the ApoE ε4 allele less frequently [ 52 ]. In addition, ApoE ε4 allele was protective for MCI only in Han Chinese but not in Hui Chinese [ 53 ].…”