Is There a Link Between Loss of Sleep and Alzheimer’s Disease?
Doctors and researchers have long known that there is a link between symptomatic Alzheimer’s disease and sleep disruption. Those with the disease often struggle with sleep problems but researchers now suspect that sleep loss and disrupted sleep may show up before a person becomes symptomatic. If this is true, it could open the door to earlier diagnosis, different treatment options, and the potential for better outcomes.
In order to determine if their theories were true, the research team at Washington University School of Medicine in St Louis set out to confirm that sleep disruptions can be seen in people who are in the early stages of Alzheimer’s. They recruited 145 participants whose spinal fluid was analyzed for the presence of pre-clinical Alzheimer’s disease markers. In essence, the participants were screen to see if they had the beginnings of Alzheimer’s even though they were not symptomatic. The analysis showed that 32 of the 45-75 year old participants had the markers in their spinal fluid samples.
The team then asked all participants to keep a sleep journal and wear an activity monitor for two weeks. The sleep journal captured sleep duration, what time participants went to sleep, what time they got up, if they took any naps, and other pertinent sleep information. The activity sensor was used to gauge how much time the participants actually spent asleep regardless of how long they spent in bed.
The findings confirmed the belief that those with preclinical Alzheimer’s disease experienced more sleep disruptions and had more difficulty sleeping than those who did not have the markers. Although they spent as much time in bed as the other participants, those with the markers got less sleep overall and were more likely to take naps. The data indicates that the participants who slept the worst were also the most likely to have the markers, nearly 5 times as likely as those participants who did not struggle with sleep.
While this study confirms the link between preclinical Alzheimer’s disease and disrupted sleep, it isn’t clear if sleep problems increase the likelihood of developing Alzheimer’s or if having the early stages of Alzheimer’s causes sleep disruptions or if this connection works both ways. Additional research will need to be done to answer that question.
The findings do provide hope that sleep disruption may be able to be used as an early warning sign of Alzheimer’s prior to a person developing symptoms. If doctors are able to identify the disease in the earliest stages before it causes significant changes in the brain, they may be able to use different treatment strategies to keep it from becoming symptomatic. Doctors may also be able to use sleep as a barometer for measuring the effectiveness of other treatments for the disease.