Changes in Physical Activity and the Risk of Dementia in Patients with New-Onset Type 2 Diabetes: A Nationwide Cohort Study

OBJECTIVE:We investigated the association between interval changes in physical activity (PA) and dementia risk among patients with new-onset type 2 diabetes.RESEARCH DESIGN AND METHODS:We identified 133,751 participants newly diagnosed with type 2 diabetes in a health screening (2009-2012), with a follow-up health screening within 2 years (2010-2015). PA level changes were categorized into continuous lack of PA, decreaser, increaser, and continuous PA groups. Dementia was determined using dementia diagnosis codes and antidementia drug prescriptions.RESULTS:During the median follow-up of 4.8 years, 3,240 new cases of all-cause dementia developed. Regular PA was associated with lower risks of all-cause dementia (adjusted hazard ratio [aHR] 0.82; 95% CI 0.75-0.90), Alzheimer disease (AD) (aHR 0.85; 95% CI 0.77-0.95), and vascular dementia (VaD) (aHR 0.78; 95% CI 0.61-0.99). Increasers who started to engage in regular PA had a lower risk of all-cause dementia (aHR 0.86; 95% CI 0.77-0.96). Moreover, the risk was further reduced among those with continuous regular PA: all-cause dementia (aHR 0.73; 95% CI 0.62-0.85), AD (aHR 0.74; 95% CI 0.62-0.88), and VaD (aHR 0.62; 95% CI 0.40-0.94). Consistent results were noted in various subgroup analyses.CONCLUSIONS:Regular PA was independently associated with lower risks of all-cause dementia, AD, and VaD among individuals with new-onset type 2 diabetes. Those with continuous regular PA and, to a lesser extent, those who started to engage in regular PA had a lower risk of dementia. Regular PA should be encouraged to prevent dementia in high-risk populations and those with new-onset type 2 diabetes.