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

<b>Objective:</b> We investigated the association between interval changes in physical activity (PA) and dementia risk among patients with new-onset type 2 diabetes. <p><b>Methods: </b>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 the continuous lack of PA, decreaser, increaser, and continuous PA groups. Dementia was determined using dementia diagnosis codes and anti-dementia drug prescriptions.</p> <p><b>Results:</b> 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’s 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)<b>, </b>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.</p> <p><b>Conclusions: </b>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.</p>