Abstract

Dementia development has been linked to sleep problems, but the type and extent of this link are still unknown. The future dementia risk was examined in this systematic review and meta-analysis according to several sleep disorders. Based on 15 longitudinal studies released from 2020 up to December 2025, a thorough review and meta-analysis were carried out. These studies monitored 2,281,507 individuals from several nations for periods ranging from four to forty years. Different sleep disorders were investigated among the studies, including insomnia, sleep disturbance, excessive daytime sleepiness (EDS, and restless leg syndrome (RLS). Meta-analysis was conducted to assess the hazard ratio (HR) of the development of dementia among patients with sleep disorders. The Meta-analysis found that all-cause sleep disorders were associated with a significantly higher risk for dementia (HR: 1.13, 95% CI: 1.05–1.22, p-value=0.0082). Among different sleep disorders, EDS showed the highest risk for development dementia with HR of 1.41 (95% CI: 1.17-1.71), followed by RLS (HR: 1.29, 95% CI: 1.04–1.60), inomnia (HR: 1.19, 95 % CI: 1.06-1.35), sleeping for less than 7 hours or more than 8 hours (HR: 1.18). Poor sleep quality and difficulties in falling asleep did not show a significant correlation with the risk of dementia. The current systematic review confirmed the significant association between sleep disorders and the chance of developing future dementia. These findings indicated the importance of managing sleep disorders as a modifiable risk for the prevention of future dementia.

Key words: Sleep disorders, risk, dementia, systematic review, meta-analysis.