Regular physical activity was found to be independently associated with a decreased risk of all-cause dementia, Alzheimer disease, and vascular dementia among patients with new-onset type 2 diabetes, according to the results of a study published in Diabetes Care.
Researchers obtained data from the Korean National Health Insurance Service database to identify 133,751 patients aged 40 years and older with new-onset type 2 diabetes who had undergone health screening from 2009 to 2012 and follow-up screening within 2 years (2010-2015). The participants were followed up from their last health screening to any incidence of dementia, death, or end of the study period on December 31, 2017, whichever came first.
The patients were categorized into groups according to their physical activity level: continuous lack of physical activity (n=86,643; mean age, 57.6±9.8 years; 61.1% men), decreased physical activity (n=14,396; mean age, 59.1±9.3 years; 65.0% men), increased physical activity (n=21,159; mean age, 57.2±9.1 years; 67.3% men), and continuous physical activity (n=11,553; mean age, 58.2±9.0 years; 74.1% men). Regular physical activity was defined as at least 30 minutes of moderate physical activity occurring at least 5 times per week or at least 20 minutes of vigorous physical activity occurring at least 3 times per week. Newly diagnosed dementia categorized as Alzheimer disease and vascular dementia was the study end point.
After a median follow-up of 4.8 years (interquartile range, 3.8-5.8 years), 3240 new cases of all-cause dementia were recorded, 74.7% (2420 cases) of which were Alzheimer disease and 14.5% (469 cases) of which were vascular dementia. Regular physical activity was found to be associated with a lower risk of all-cause dementia after adjustment for all potential confounding variables (adjusted hazard ratio [aHR] 0.82; 95% CI, 0.75-0.90), Alzheimer disease (aHR 0.85; 95% CI, 0.77-0.95), and vascular dementia (aHR 0.78; 95% CI, 0.61-0.99).
Participants in the increased physical activity group who initiated regular physical activity during the 2-year interval had a lower risk of all-cause dementia (aHR 0.86; 95% CI, 0.77-0.96). The risk was further decreased in patients who participated in continuous regular physical activity (all-cause dementia [aHR 0.73; 95% CI, 0.62-0.85], Alzheimer disease [aHR 0.74; 95% CI, 0.62-0.88], and vascular dementia [aHR 0.62; 95% CI, 0.40-0.94]).
In subgroup analysis, the continuous regular physical activity group without stroke were found to be at lower risk for vascular dementia (aHR 0.63; 95% CI, 0.41-0.97).
Study limitations include data on physical activity based on a self-administered questionnaire and limited to a short time span. Also, the etiologic diagnosis of dementia was not based on biomarkers of Alzheimer disease, and the investigators did not have information such as apolipoprotein ε4 carrier status and education level. Furthermore, the selection of study participants based on repeated participation in health examinations could be a source of bias.
“These findings suggest that regular physical activity should be encouraged to prevent dementia in high-risk populations and those with recent-onset type 2 diabetes,” the study authors stated.
Yoo JE, Han K, Kim B, et al. Changes in physical activity and the risk of dementia in patients with new-onset type 2 diabetes: a nationwide cohort study. Diabetes Care. Published online February 22, 2022. doi:10.2337/dc21-1597