Exercise Is Related to Reduced Mortality Risk Among Patients With Dementia

Sustained engagement in physical activity, regardless of intensity, is associated with reduced all-cause mortality risk in individuals diagnosed with dementia, according to study findings published in the British Journal of Sports Medicine.

Researchers conducted a retrospective cohort study to assess the relationships between the amount and changes in physical activity before and after a dementia diagnosis and the risk for all-cause mortality, as well as whether these relationships differ by physical activity intensity.

Data were sourced from the Korean National Health Insurance Service database. Individuals aged 40 and older who were newly diagnosed with dementia between January 2010 and December 2016 and underwent health examinations within 2 years before and after the diagnosis were eligible for inclusion.

The International Physical Activity Questionnaire-Short Form (IPAQ-SF) was used to evaluate physical activity. Physical activity was classified as vigorous, moderate, or light. Participants were divided into 4 groups depending on the changes in regular physical activity within 2 years before and after the dementia diagnosis (non-exercisers, quitters, starters, and maintainers). Further, individuals were categorized into 4 groups according to changes in engagement in each intensity of physical activity.

The primary outcome was all-cause mortality through December 2019. To analyze the associations between physical activity and all-cause mortality risk, multivariable Cox proportional hazards regression models were used.

A total of 60,252 individuals (mean age, 74.1; men, 38.6%; Alzheimer disease [AD], 71.8%) were included in the study, of whom 47,050 (78.1%) were non-exercisers, 6212 (10.3%) were quitters, 4801 (8.0%) were starters, and 2189 (3.6%) were maintainers.  

Over a mean follow-up period of 3.7 years, 16,431 (27.3%) deaths were recorded.

Higher levels of physical activity following a dementia diagnosis were strongly associated with a significantly reduced risk for mortality (P <.001).

The maintenance of regular physical activity vs the maintenance of no physical activity was associated with the lowest risk for mortality (hazard ratio [HR], 0.71; 95% CI, 0.65-0.79).

Maintaining physical activity of any intensity was associated with a decreased risk for mortality:

• Light physical activity: HR, 0.70; 95% CI, 0.67-0.75;
• Moderate physical activity: HR, 0.74; 95% CI, 0.64-0.86;
• Vigorous physical activity: HR, 0.70; 95% CI, 0.61-0.79.

These relationships were consistent in populations with AD.

Study limitations include the retrospective cohort design, lack of data pertaining to the type of physical activity, potential misclassification and recall bias, reliance on self-reported data, and reduced generalizability of results to more diverse population samples.

“Considering lifestyle factors, health examination data and severity of dementia, our results emphasize the maintenance and initiation of PA [physical activity] after dementia diagnosis, regardless of intensity, to reduce mortality risk,” the researchers concluded.