NEW DELHI: Older people who are sleepy during the day or lack enthusiasm for activities due to sleep issues may be more likely to develop a condition that can lead to dementia, according to a study.
The study, published in the journal Neurology, said people suffering from the condition, cognitive risk syndrome (MCR), which is a pre-dementia syndrome, are characterized by slow gait speed, have some memory issues, and have cognitive complaints.
Among participants who reported excessive daytime sleepiness and a lack of enthusiasm, 35.5% developed MCR compared with 6.7% of people without those problems.
The study found that people with excessive daytime sleepiness and a lack of enthusiasm to get things done were likelier to develop the syndrome than those without sleep-related issues.
“Our findings emphasize the need for screening for sleep issues,” said study author Victoire Leroy 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 involved 445 people with an average age of 76 who did not have dementia. Participants took questionnaires for sleep at the start of the study. They were asked about memory issues and their walking speed was tested on a treadmill at the start of the study and then once a year for an average of three years.
The sleep assessment asked questions like how often people had trouble sleeping because they wake up in the middle of the night, cannot fall asleep within 30 minutes, or feel too hot or cold and whether they take medicine to help them sleep.
The question to assess excessive daytime sleepiness asks how often people have had trouble staying awake while driving, eating meals, or, engaging in social activity. The question on enthusiasm asked how much of a problem people have had keeping up enough enthusiasm to get things done.
A total of 177 people met the definition for poor sleepers and 268 met the definition for good sleepers.
At the start of the study, 42 people had motoric cognitive risk syndrome. Another 36 people developed the syndrome during the study.
Once researchers adjusted for other factors that could affect the risk of the syndrome, such as age, depression, and other health conditions, they found that people with excessive daytime sleepiness and lack of enthusiasm were more than three times more likely to develop the syndrome than those who did not have those sleep-related problems, the researchers said.
According to the World Health Organisation (WHO), there are more than 55 million people who have dementia worldwide, over 60% of whom live in low-and middle-income countries. Every year, there are nearly 10 million new cases.
“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.”
Dementia results from a variety of diseases and injuries that affect the brain. Alzheimer disease is the most common form of dementia and may contribute to 60–70% of cases.
Dementia is currently the seventh leading cause of death and one of the major causes of disability and dependency among older people globally.
In 2019, dementia cost economies globally US$ 1.3 trillion, approximately 50% of these costs are attributable to care provided by informal carers (e.g. family members and close friends), who provide on average 5 hours of care and supervision per day, the WHO said.
Women are disproportionately affected by dementia, both directly and indirectly. Women experience higher disability-adjusted life years and mortality due to dementia, but also provide 70% of care hours for people living with dementia.