Education and its effect on risk and age at onset in Alzheimer disease (AD) in African Americans: Genetics/genetic factors of Alzheimer's disease. (7th December 2020)

• Record Type: Journal Article
• Authors: Adams, Larry D.; Slifer, Susan H.; Ramos, Jairo; Inciute, Jovita D.; Starks, Takiyah D.; Scott, Aja M.; Lacroix, Faina C.; Laux, Renee A.; Haines, Jonathan L.; Vance, Jeffery M.; Cuccaro, Michael L.; Byrd, Goldie S.; Beecham, Gary W.; Pericak‐Vance, Margaret A.
• Is Part Of: Alzheimer's & dementia. Volume 16(2020)Supplement 3
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-07
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.046078
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: Increased years of education have been previously associated with a decreased risk of developing Alzheimer disease (AD) with cognitive reserve suggested as the source of the protective effect in Non‐Hispanic Whites (NHW). African Americans (AA) are twice as likely to develop AD compared to NHW. We investigated the hypothesis that education was similarly correlated with risk of AD in the AA population. We also examined the relationship of education and age at onset (AAO) of AD in AA. Method: Participants consisted of 132 AA AD cases and 428 AA cognitively intact (CI) individuals with known years of completed education, ascertained for a genetics study of AD. Education levels were stratified into three categories: < 8 years, 9‐12 years, >12 years. We used logistic regression to determine the effect of age, sex, education level and APOE4 status between cases versus controls. Additionally, using a linear model we examined the effect of education on AAO including sex and APOE4 status as covariates. Result: Results showed that increasing years of education had a protective effect on AD risk. Initially including sex and age as covariates, both higher education categories were significant, with 9‐12 years (p = 0.02;OR = 0.461[0.23, 0.9])) and >12 years (p = 1.30e0‐04;OR = 0.26[0.13, 0.41]). Adding APOE4 dosage (0(Ref), 1, 2 alleles) to the model (significant at p = 9.54e‐05; p = 5.27e‐07), the effect of education remained significant (p = 0.03;OR = 0.46[0.23, 0.93]) and p = 4.84e‐05;OR = 0.22[0.10, 0.46]) for 9‐12 and >12, respectively further supporting its role in AD risk. We examined the effect of education on AAO. Education (8‐12 years) trended in significance (p‐value = 0.07; β = ‐3.76[‐7.82, 0.307]) with >12 years significant (p‐value = 1.63e‐04; β = ‐13.07, ‐4.25]) supporting later AAO with higher education. The effect of APOE4 on AAO was not significant (p = 0.226). APOE 4 added to the model as a covariate did not have a significant effect on AAO, however, education levels continued trending (8‐12; p = 0.07; β = ‐3.76[‐7.86, 0.34]) and significant (>12; p = 3.71e‐04; β = ‐8.33[‐12.84, ‐3.82]). Conclusion: These data support the hypothesis that higher education results in a decreased risk of AD in AA regardless of APOE4 status. We also found a similar protective effect for a later AAO. Thus, the potential outcome of education on cognitive reserve appears across multiple racial backgrounds.