Association between APOε4 allele and cognitive function in healthy Brazilians elderly from Baixada Santista

Abstract Background The faster memory decline was associated with the presence of the apolipoprotein E4 (APOε4) allele, a genetic risk factor for late‐onset Alzheimer’s disease (AD). Studies suggest that the relationship between cognitive decline and APOE ε4 allele in healthy elderly may reflect the preclinical risk to AD. This study examined the influence of apolipoprotein E4 (APOε4) genotype on the cognitive function of the older people from Baixada Santista (Brazil). Method This study was approved by the Ethical Committee Board from Medical School/UNIMES (Number: CAAE 20938619.4.0000.5509). Seventy‐two participants with ≥65 years old, both sexes. were eligible for the study. Cognitive function and the level of physical activity were assessed by the mini‐mental state examination (MMSE) and Baecke questionnaire for older, respectively. APOE genotyping was performed in 66 out of the 72 participants. Statistical analysis was performed by using the BioEstat version 5.0, Kolmogorov‐Smirnov test, z‐score, student t or Mann‐Whitney test was applied according to the normality. The Chi‐square test was used for comparison between the sexes. Pearson correlation was also performed. P < 0.05 was considered statistically significant. Results Seventy‐two older people were assessed (women = 52 and men = 20), and the mean age was 73±7 years old, Baecke score (3.74 ±3.82), MMSE (27±3), and educational status (8 ± 4 years). As expected, a positive correlation was detected between the education level and MMSE score (r = 0.359, p < 0.05). No difference was found between the sexes for age, level of physical activity, MMSE, and education status (p > 0.05). Regarding the APOE genotype, we found the following frequency ɛ2/ɛ2 (1.5%), ɛ2/ɛ3 (16.7%), ɛ2/ɛ4 (1.5%), ɛ3/ ɛ3 (59.1%), and ɛ3/ɛ4 (21.2%). No correlation was found between carriers (presence of the ɛ4 allele) and non‐carrier for the MMSE score, varying between 27 to 30. Conclusion Our preliminary data show that the less educational status influences the cognitive decline in the older Brazilian population. However, no differences between the sexes were observed for all parameters indicating a homogenous population. Additionally, the cognitive function score was not influenced by the presence of the APOɛ4 allele in this population.