Association Between Mentally Stimulating Activities in Late Life and the Outcome of Incident Mild Cognitive Impairment, With an Analysis of the APOE ε4 Genotype

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e187">Importance</h5> <p id="P1">We and others have reported cross-sectional associations between mentally stimulating activities and decreased odds of having mild cognitive impairment (MCI) or Alzheimer’s disease. However, little is known about the longitudinal outcome of incident MCI as predicted by late life (age ≥70 years) mentally stimulating activities. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e192">Objective</h5> <p id="P2">To test our hypothesis on the association between mentally stimulating activities in late life and the risk of incident MCI and additionally evaluate the impact of APOE ε4 genotype. </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e197">Design</h5> <p id="P3">Prospective cohort study.</p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e202">Setting</h5> <p id="P4">Population-based Mayo Clinic Study of Aging in Olmsted County, Minnesota. </p> </div><div class="section"> <a class="named-anchor" id="S5"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e207">Participants</h5> <p id="P5">We followed 1929 participants aged ≥ 70 years who were cognitively normal at baseline to the outcome of incident MCI. </p> </div><div class="section"> <a class="named-anchor" id="S6"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e212">Main Outcome and Measures</h5> <p id="P6">At baseline, participants provided information about mentally stimulating activities within a year prior to enrolment into the study. Neurocognitive assessment was conducted at baseline and 15 month interval evaluations. Cognitive diagnosis was made by an expert consensus panel based on published criteria. We calculated hazard ratios (HR) and 95% confidence intervals (95% CI) using Cox proportional hazards models after adjusting for age, sex and education. </p> </div><div class="section"> <a class="named-anchor" id="S7"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e217">Results</h5> <p id="P7">Over a median follow-up period of 4 years, we observed that playing games (HR [95% CI], 0.78 [0.65–0.95]), and engaging in craft activities (0.72 [0.57–0.90]), computer use (0.70 [0.57–0.85]), and social activities (0.77 [0.63–0.94]) were associated with a decreased risk of incident MCI. In a stratified analysis by APOE ε4 status, the data points towards the lowest risk of incident MCI for APOE ε4 non-carriers who engage in mentally stimulating activities and towards the highest risk of incident MCI for APOE ε4 carriers who do not engage in mentally stimulating activities. </p> </div><div class="section"> <a class="named-anchor" id="S8"> <!-- named anchor --> </a> <h5 class="section-title" id="d14852744e222">Conclusion and Relevance</h5> <p id="P8">Cognitively normal elderly individuals who engage in specific mentally stimulating activities, even in late life, have a decreased risk of incident MCI. The associations may vary by APOE ε4 carrier status. </p> </div>