Of 3 modifiable behaviors known to be associated with dementia, combining sleeping 7 h/d, moderate-to-high leisure-time physical activity (LTPA), and low-to-moderate sedentary time had the lowest risk of incident dementia.
Putting It Into Practice
The 2020 Report of the Lancet Commission concluded that modification of 12 modifiable risk factors could reduce the incidence of dementia by 40%.
Risk profiling is best achieved when the independent and combined effect of modifiable and non-modifiable risk factors are determined.
Why this study matters
Notwithstanding a cure, the global prevalence of dementia is expected to triple in the next 3 decades. Thus, prevention, risk reduction, and cognitive enhancement rely on an understanding of the modifiable cardiovascular and lifestyle risk factors.
Participants (n = 431,924) without dementia at the time of enrollment were recruited from the UK Biobank and followed for a median of 9 years.
The following data were collected and fitted with restricted cubic spine to determine linear and non-linear association with dementia: sleep duration; LTPA; and sedentary time.
Results and conclusion
Duration of sleep had a U-shaped association with dementia; 7 h of sleep per day had the lowest risk of dementia. LTPA had a curvilinear association with dementia, while sedentary time had a J-shaped association with dementia.
The risk of dementia was 17% lower in participants with high LTPA and 22% higher in participants with high sedentary time.
Each of the 3 modifiable behaviors had a non-linear association with brain structures corresponding to dementia.
Huang SY, Li YZ, Zhang YR, et al. Sleep, physical activity, sedentary behavior, and risk of incident dementia: a prospective cohort study of 431,924 UK Biobank participants. Mol Psychiatry. Published online June 14, 2022:1-12.