Decreased physical activity during leisure time correlated with increased risk for developing non-Alzheimer dementia regardless of physical activity levels at work and other modifiable risk factors, according to study findings published in Atherosclerosis.
Researchers conducted a prospective cohort study of 117,616 individuals from the Copenhagen General Population Study (CGPS) and the Copenhagen City Heart Study (CCHS), aged 20-100 years, with up to 43 years of follow-up to assess whether the intensity of physical activity at work and during leisure time affected dementia risk in these individuals. A total of 4391 individuals developed dementia within a median follow-up of 10 years.
The researchers categorized study participants into 3 different groups according to physical activity intensity level — low (8% of participants; mean age, 55 years), moderate 44% of participants; mean age, 59 years), or high (48% of participants; mean age, 57 years) — at work and during leisure time. Physical activity levels were self-reported.
The researchers found that low physical activity levels at leisure time correlated with higher likelihood of developing non-Alzheimer dementia (adjusted hazard ratio [aHR], 1.60; 95% CI, 1.40-1.83), more so than Alzheimer disease (AD; aHR, 0.94; 95% CI, 0.80-1.11). Individuals maintained this trend withing 2, 5, or 10 years from baseline.
In contrast, individuals with higher physical activity levels at work were more likely to develop non-Alzheimer dementia (aHR, 1.21; 95% CI, 0.93-1.58) and AD (aHR, 1.41; 95% CI, 1.00-1.99). The researchers noted that individuals with higher physical activity levels at work and lower physical activity levels at leisure were more likely to develop non-Alzheimer dementia than those with lower levels of physical activity at work and higher physical activity levels at leisure. They observed similar trends when adjusting for apolipoprotein E (APOE) genotype.
“Physical inactivity in leisure time was associated with increased risk of non-Alzheimer’s dementia, but not Alzheimer’s disease, independent of modifiable risk factors and physical activity at work,” the researchers stated. “The present study thus provides evidence for public health advice on physical activity in leisure time for the large part of dementia that mainly is due to vascular factors.”
Study limitations include use of registry-based diagnoses which may result in underdiagnosis and limited generalizability of the study due to inclusion of only White individuals from Denmark.
Rasmussen IJ, Rasmussen KL, Thomassen JQ, et al. Physical activity in leisure time and at work and risk of dementia: a prospective cohort study of 117,616 individuals. Atherosclerosis. Published online August 17, 2022. doi:10.1016/j.atherosclerosis.2022.08.004