APOE ε4 and Decline in Health and Financial Literacy in Advanced Age

BACKGROUND: Health and financial literacy decline in aging, but it is unclear why. In this study, we hypothesized that older people who are carriers of the APOE ε4 allele exhibit a steeper decline in literacy over time. METHODS: Participants were 851 community-dwelling older adults without dementia at analytic baseline (188 ε4 carriers and 663 noncarriers). Literacy was assessed at baseline and each year thereafter for up to 14 years. RESULTS: In a linear mixed-effects model adjusted for age, gender, and education, ε4 was associated with a lower starting level of literacy (b = -3.60, SE b = 1.00, p < 0.001) and, critically, a roughly 40% steeper decline in literacy over time (b = -0.41, SE b = 0.14, p = 0.004). The association between ε4 and literacy decline persisted after adjusting for global cognition at baseline (b = -0.35, SE b = 0.14, p = 0.012) and among a subgroup of participants with no cognitive impairment at baseline (b = -0.34, SE b = 0.14, p = 0.016). CONCLUSIONS: ε4 contributes to literacy decline among older adults, presumably due in part to the accumulation of neuropathologies associated with ε4. We discuss the potential clinical implications of ε4-related literacy decline.