Association between APOEε4 genotype and cardiovascular risk factors in Mexican elderly adults with amnestic and non‐amnestic mild cognitive impairment

Abstract

Background The prevalence of mild cognitive impairment (MCI) is 14 to 18%. MCI has been associated with cardiovascular risk factors. Likewise, the APOEε4 genotype is a gene that confers susceptibility to Alzheimer’s disease. However, the association between APOE genotype, cardiovascular risk and MCI in the Mexican population is not clear, probably as a result of genetic heterogeneity. Method We included patients from memory clinic (INCMNSZ) from 2017 to 2019, > 70 years. Three groups were studied: controls without cognitive impairment, with amnestic and nonamnestic MCI. Parametric and nonparametric statistics (x2, ANOVA, multivariate logistic regression analysis, Kruskal‐Wallis) were used for the analysis of statistical differences between groups. Result 131 patients were studied, 67.9% were women, the average age was 73.6 (SD 7.3) and the educational level was 12.62 (SD 4.98). Regarding the APOE genotype, 93 (71%) were e3 / e3, 35 (26.7%) e3 / e4, 3 (2.3%) e4 / e4. Three groups of cognitive function were formed: cognitively healthy controls: 59 (45%), amnestic MCI: 29 (22.1%) and nonamnestic MCI: 42 (32.1%). In the group with nonamnestic MCI, statistically significant differences were found in dyslipidemia 48% (P = 0.014), history of CVD 16.5% (P = 0.033) and anemia 8% (0.034). For the group with amnestic MCI, 44.4% hypothyroidism was found (p = 0.15). The multivariate logistic regression analysis showed that the APOE genotype did not significantly modify the association with cardiovascular risk factors and MCI. A greater effect on motor executive function was found in the group of carriers of the APOEε4 genotype (p = 0.042) Conclusion Our study found a low frequency of APOE ε4, compared to African or European populations (Pygmy population, khoisan, waiwai) where the frequency is high (possibly related to race). Previous studies have shown an association between cardiovascular risk and cognitive risk in patients with APOE ε4, however, our study does not show an association between the state of APOE and risk for cognitive impairment, possibly related to variability genetics of the Mexican population, as well as the existence of possible polymorphisms not described in this population. Few studies have shown the association between APOE ε4 polymorphism, hypothyroidism and amnestic DCL.