Impact of Sleep Disturbance on Dementia in Elderly Individuals: Sleep Disturbances and Dementia Risk

Researchers are focusing on modifiable risk factors for dementia, including sleep disturbances such as insomnia and sleep-disordered breathing (SDB), which are known to increase the risk of dementia, including Alzheimer’s disease (AD) and vascular dementia (VD). Sleep deprivation promotes amyloid beta (Aβ) accumulation. Inappropriate sleep duration can increase the risk of AD and VD by increasing inflammatory responses. SDB can increase the risk of VD by inducing white matter changes through sleep apnea, promote Aβ formation through hypoxia, and induce hippocampal atrophy to increase the risk of AD. Sleep-related movement disorders (SRMDs) are associated with a 4-fold greater risk of incident all-cause dementia and an increased risk of VD than AD. Studies have indirectly shown that several SRMDs are related to dopaminergic or cholinergic pathways. This review reveals a meaningful association between sleep disturbance and dementia. However, literature regarding the clear pathological mechanism and causal relationship involved is lacking, confirming the need for additional research.