Date Published: June 1, 2018
Publisher: JKL International LLC
Author(s): Jie Zhen, Tong Lin, Xiaochen Huang, Huiqiang Zhang, Shengqi Dong, Yifan Wu, Linlin Song, Rong Xiao, Linhong Yuan.
Apolipoprotein E (ApoE) gene polymorphism has been implicated in predisposition to diabetes and dementia in old population, but the results from the different studies were inconclusive. A cross-sectional study was carried out to explore the relationship among ApoE gene polymorphism, diabetes and cognition in non-demented aging Chinese adults. A total number of 1000 community dwellers aged 55 years and above were randomly recruited. Demographic information of the participants was collected using well designed self-administered questionnaires. The Montreal Cognitive Assessment (MoCA) test was employed to evaluate the cognitive status of the participants. Semi-quantitative food frequency questionnaire was used to obtain the dietary intake information. Fasting venous blood samples were taken for ApoE genotyping and serum lipid measurements. 238 participants were type 2 diabetes mellitus (T2DM) patients and 145 participants were ApoE4 carriers. ApoE 4-T2DM subjects had higher serum triglyceride (TG) concentration than E2 and E3 carriers (P < 0.05). T2DM subjects carrying ApoE4 had lower cognition than subjects with E2 or E3 carriers (P < 0.05). Comparing to non-type 2 diabetic mild cognitive impaired (nT2DM-MCI) subjects, the type 2 diabetic mild cognitive impaired (T2DM-MCI) subjects have higher serum glucose (Glu) level and lower high-density lipoprotein (HDL-C) level (P < 0.05). The T2DM-MCI subjects carrying ApoE4 have lower cognition than E2 and E3 carriers (P <0.05); and the interaction of ApoE genotype with T2DM was detected (P < 0.05). Our results indicated the association among ApoE gene polymorphism, T2DM and cognitive performance in non-demented aging population. The carrying of ApoE4 predisposed the T2DM subjects and the T2DM-MCI subjects to have poor cognitive performance. Additional experimental studies are required to explore the mechanism that ApoE genotype modifies the risk for cognitive impairment in aging subjects with T2DM.
Higher MCI prevalence was observed in T2DM patients than in the general population [28, 29]. Patients with both T2DM and MCI had a faster cognitive deterioration process than patients with MCI only . All these data indicated that T2DM is a risk factor for the old population to have cognition decline. In the present study, we carried out a community based cross-sectional study trying to explore the association of ApoE genetic polymorphism, T2DM and cognition in non-demented aging Chinese adults. In the present study, we detected the ApoE genotype difference of cognitive performance in subjects with T2DM. The ApoE4-T2DM subjects have the lowest cognition as comparing with T2DM subjects carrying E2 or E3. Moreover, the carrying of ApoE4 predisposed the T2DM-MCI subjects to have much poor cognitive performance.
In summary, our data implicated the association among ApoE gene polymorphism, T2DM and cognition in non-demented aging Chinese adults. The ApoE4-T2DM subjects and ApoE4-T2DM-MCI subjects were predisposed to have poor cognitive performance. In the future, long time cohort studies were needed with regard to how genetic background modulates the association between diabetes and cognitive function in aging population. The precise biological mechanism underlying this significant association should be investigated.