Bilingualism and APOE4 alelle as a risk‐protective factor in dementia among Peruvian Andean aging population
Marcio F. Soto‐Añari, Claudia Rivera‐Fernandez, Luis Ramos‐Vargas, Nilton Custodio, Rosa Montesinos, Diego Chambergo‐Michilot, Maria Fernanda Ore‐Gomez, Jose Carreño‐Galvez, Dolly Reyes‐Dumeyer, Giuseppe Tosto- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Bilingualism has been considered as a protective factor against dementia. But the evidence in Native American populations is spare and to our knowledge, there are no studies analyzing risk factors, as the APOE4 genotype and environmental protective factors as the bilingualism and education. Our objective was to analyze the risk/protective association between bilingualism and APOE4 status (carrier/non‐Carrier) on Alzheimer Dementia Related Disorders (ADRD). In addition, we analyzed the impact of the bilingual/monolingual condition on cognition.
Method
We used the data of the ongoing study “Genetics of Alzheimer’s disease in Peruvian Populations study” (GAPP). 275 older adults (mean age = 71.57, SD = 8.3) were recruited from 3 Peruvian cities: Lima, Arequipa and Puno. These last located in the southern of Peru where Quechua and Aymara ethnics are the most important population. Bilingual condition was evaluated as a dichotomous condition (yes/no). A clinical and neuropsychological protocol was applied which included brief cognitive test, functional status measures and clinical dementia scales (CDR). Cognitive measures included attention, memory, abstract reasoning, language and visuoconstruction. Genotyping was conducted on The Infinium Global Screening Array‐24 BeadChip, which combines multi‐ethnic genome‐wide content. Binary logistic regression was performed taking the CDR 1 score as the dependent variable and gender, education, being bilingual/monolingual, and APOE4 Carrier/non‐Carrier status as predictors. Finally, we use mean comparison test in cognition measures according the bilingual/monolingual condition.
Result
We observed that bilingualism (OR = 0.23, p<.001), APOE non‐carrier status (OR = 0.26, p<.001) and more years of schooling (OR = 0.92, p<.01) are associated with a lower risk of dementia. We also see that bilinguals have better scores than monolinguals in orientation tasks (t = 2.65, p<.01), memory total recall (t = 2.02, p<.05), semantic fluency‐animals (t = 2.71, p<. 01) and visuoconstructional abilities (t = 6.62, p<.001). Likewise, only in perception recognition tasks, monolinguals scored higher than bilinguals (t = 3.17, p<.01).
Conclusion
Environmental factors seem to have a significant protective effect along with biological known risk factor in dementia and have a significant effect on cognition.