Daytime Sleepiness and Lack of Enthusiasm May Signal Early Dementia Risk

According to a study published in the November 6, 2024, online issue of Neurology, the medical journal of the American Academy of Neurology, older people who are sleepy during the day or lose interest in activities due to sleep issues may be more likely to develop a syndrome that can lead to dementia.

People with the syndrome walk slowly and report memory problems, but they do not have a mobility handicap or dementia. Motoric cognitive risk syndrome is a condition that can develop before dementia.

The study found that people with excessive daytime sleepiness and a lack of enthusiasm to get things done were more likely to develop the syndrome than people without those sleep-related issues. The study does not prove that these sleep-related issues cause the syndrome, it only shows an association.

“Our findings emphasize the need for screening for sleep issues,” said study author Victoire Leroy, MD, PhD, of Albert Einstein College of Medicine in the Bronx, New York. “There’s potential that people could get help with their sleep issues and prevent cognitive decline later in life.”

The study included 445 participants, with an average age of 76, who did not have dementia. Participants completed sleep surveys at the beginning of the trial. They were queried about memory problems, and their walking pace was measured on a treadmill at the beginning of the study and then once a year for the next three years.

The sleep assessment included questions about how frequently people had difficulties sleeping because they woke up in the middle of the night, couldn't fall asleep within 30 minutes, or felt too hot or cold, as well as whether they used sleep aids. The question to assess excessive daytime drowsiness asks how frequently people have had problems remaining awake when driving, eating meals, or were engaged in any other activity.

In total, 177 participants fit the category of bad sleepers, whereas 268 satisfied the definition of good sleepers.

At the outset of the trial, 42 participants had motoric cognitive risk syndrome. Throughout the trial, 36 more persons got the condition.

35.5% of patients who experienced extreme daytime sleepiness and a lack of enthusiasm developed the syndrome, compared to 6.7% who did not. After accounting for other factors that could influence the risk of the syndrome, such as age, depression, and other health conditions, researchers discovered that people with excessive daytime sleepiness and a lack of enthusiasm were more than three times more likely to develop the syndrome than those who did not have those sleep-related issues.

“More research needs to be done to look at the relationship between sleep issues and cognitive decline and the role played by motoric cognitive risk syndrome,” Leroy said. “We also need studies to explain the mechanisms that link these sleep disturbances to motoric cognitive risk syndrome and cognitive decline.”

A limitation of the study is that participants reported their own sleep information, so they may not have remembered everything accurately.

The study was supported by the National Institute on Aging.