All persons with Down syndrome (DS) will develop Alzheimer’s disease (AD) as the genetic mutation responsible for DS also promotes AD. Alzheimer’s disease in Down syndrome is very similar to AD without DS, but brain changes and dementia appear earlier. Alzheimer’s disease is now the primary cause of death in the Down syndrome population. This emphasizes the urgent need to identify and treat modifiable causes of Alzheimer’s disease in this group. Studies in the general population have found that poor sleep increases the risk of Alzheimer’s disease. Accordingly, the early diagnosis and treatment of sleep disturbances could delay the progression to dementia. Adults with DS have a high prevalence of sleep problems such as obstructive sleep apnea, but these are often underdiagnosed, masked by aging in Down syndrome. Disturbances of the sleep wake cycle—circadian disturbances (CD)—characterized by increased wakefulness during nighttime sleep and more daytime sleepiness, have not yet been studied in adults with DS. In the general population, CD can occur years before dementia onset, and represent early signs of Alzheimer’s.
This study will characterize the circadian sleep-wake disturbances in adults with DS without dementia. We will recruit 40 DS participants, from the ongoing Sant Pau hospital and domiciliary health program to detect Alzheimer’s disease in Down syndrome in Barcelona, and 20 participants without DS. All will wear a wrist actigraphy, a device that records home sleep-wake patterns for 7 days. A subset of participants will also perform a polysomnography, a hospital-based sleep study to estimate sleep apnea. We will compare circadian disturbances between individuals with and without Down syndrome and will assess if sleep apnea worsens circadian disturbances. Moreover, in relating diurnal and nocturnal actigraphy measures we will explore the underlying sleep-wake neurodegenerative process in CD. Finally, for people who may not otherwise have access to clinical settings we will evaluate the feasibility of the circadian monitoring in adults with DS in the community. This study will evaluate CD in adults with DS for the first time providing data for their accurate treatment. It will also advance our understanding of the relationship between CD and AD, with the aim of identifying early diagnostic tools and modifiable risk factors in both, DS and non DS individuals.