Association of Daily Intellectual Activities With Lower Risk of Incident Dementia Among Older Chinese Adults

Abstract

<div class="section"> <a class="named-anchor" id="ab-yoi180023-1"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e302">Importance</h5> <p id="d9660057e304">Associations between late-life participation in intellectual activities and decreased odds of developing dementia have been reported. However, reverse causality and confounding effects due to other health behaviors or problems have not been adequately addressed. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-2"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e307">Objective</h5> <p id="d9660057e309">To examine whether late-life participation in intellectual activities is associated with a lower risk of incident dementia years later, independent of other lifestyle and health-related factors. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-3"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e312">Design, Setting, and Participants</h5> <p id="d9660057e314">A longitudinal observational study was conducted at all Elderly Health Centres of the Department of Health of the Government of Hong Kong among 15 582 community-living Chinese individuals age 65 years or older at baseline who were free of dementia, with baseline evaluations performed January 1 to June 30, 2005, and follow-up assessments performed from January 1, 2006, to December 31, 2012. Statistical analysis was performed from January 1, 2015, to December 31, 2016. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-4"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e317">Main Outcomes and Measures</h5> <p id="d9660057e319">The main outcome was incident dementia as diagnosed by geriatric psychiatrists in accordance with the <i>International Statistical Classification of Diseases and Related Health Problems, Tenth Revision </i>, or a Clinical Dementia Rating of 1 to 3. At baseline and follow-up interviews, self-reported information on participation in intellectual activities within 1 month before assessment was collected. Examples of intellectual activities, which were described by a local validated classification system, were reading books, newspapers, or magazines; playing board games, Mahjong, or card games; and betting on horse racing. Other important variables including demographics (age, sex, and educational level), physical and psychiatric comorbidities (cardiovascular risks, depression, visual and hearing impairments, and poor mobility), and lifestyle factors (physical exercise, adequate fruit and vegetable intake, smoking, and recreational and social activities) were also assessed. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-5"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e325">Results</h5> <p id="d9660057e327">Of the 15 582 individuals in the study, 9950 (63.9%) were women, and the median age at baseline was 74 years (interquartile range, 71-77 years). A total of 1349 individuals (8.7%) developed dementia during a median follow-up period of 5.0 years. Multivariable logistic regression analysis showed that the estimated odds ratio for incident dementia was 0.71 (95% CI, 0.60-0.84; <i>P</i> &lt; .001) for those with intellectual activities at baseline, after excluding those who developed dementia within 3 years after baseline and adjusting for health behaviors, physical and psychiatric comorbidities, and sociodemographic factors. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-6"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e333">Conclusions and Relevance</h5> <p id="d9660057e335">Active participation in intellectual activities, even in late life, might help delay or prevent dementia in older adults. </p> </div><p class="first" id="d9660057e338">This population-based study examines whether late-life participation in intellectual activities is associated with a lower risk of incident dementia years later, independent of other lifestyle and health-related factors among community-living Chinese individuals 65 years of age or older. </p><div class="section"> <a class="named-anchor" id="ab-yoi180023-7"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e344">Question</h5> <p id="d9660057e346">Does participation in intellectual activity reduce the risk of dementia in older adults, independent of other healthy lifestyle practices such as regular physical exercise, adequate fruit and vegetable intake, and not smoking? </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-8"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e349">Findings</h5> <p id="d9660057e351">In this population-based study, 15 582 community-living Chinese individuals age 65 years or older who were free of dementia were followed up for a median period of 5 years. Daily participation in intellectual activities was associated with a significantly lower risk of dementia several years later independent of other health behaviors, physical health limitations, and sociodemographic factors. </p> </div><div class="section"> <a class="named-anchor" id="ab-yoi180023-9"> <!-- named anchor --> </a> <h5 class="section-title" id="d9660057e354">Meaning</h5> <p id="d9660057e356">Active participation in intellectual activities, even in late life, might help prevent dementia in older adults. </p> </div>