Contrary to the usual, what is the relationship between sleep and dementia?

Contrary to the usual, what is the relationship between sleep and dementia?

China has the world's highest number of people with dementia, a neurodegenerative disorder, with at least 6% of older adults, or one in 20 people aged 60 or older, living with dementia.

According to what was published by "Medical News Today", citing the Journal of the American Geriatrics Society, a recent Chinese population study of elderly people in rural China linked between prolonged sleep and early bedtime and an increased risk of dementia.

The study also found that even in those who did not develop dementia during the study period, there was still a possibility that they had some degree of cognitive decline associated with prolonged sleep and earlier bedtime. But the discovery, new of its kind, was only evident in older adults between the ages of 60 and 74, and men in particular.

Sleep and dementia risks

Sleep is a complex biological process. Aging-related changes in sleep timing and quality are associated with cognitive disorders, said Dr. Verna Porter, a neurologist and director of the division of dementia, Alzheimer's disease and neurocognitive disorders at Providence Saint John's Health Center in Santa Monica, California, who was not involved in the current research. that [studies] assess non-white (Caucasian), mostly urban populations from North America or Western Europe,” noting that the new Chinese study focused on “assessing rural adults from China, including their unique social, economic, cultural, and educational practices of its kind.”

Rural dementia

Older people in rural China tend to sleep and wake up earlier, and generally have lower quality sleep than people in urban areas. Research indicates that dementia occurs more often in rural areas of the country than in developed areas.

The aim of the study, which was started in 2014 by scientists from a number of Chinese institutions and research centers and included elderly people in rural areas in western Shandong Province, was to "examine the associations of self-reported sleep characteristics (for example, time spent in bed). and timing, duration, and quality of sleep) and between EDS and EDS with episodic dementia, Alzheimer’s disease and cognitive decline, taking into account possible interactions [as a result of differences in] demographic features and APOE genotype.”

The main risks

The results revealed that the risk of developing dementia was 69% higher for individuals who slept more than 8 hours, versus 7-8 hours. The risk also doubled for those who went to bed before 9:00 pm, versus 10:00 pm or after.

The "breadwinner" man

The study also found that there was an association between sleeping early or late and with a greater or lesser decrease in the degree of cognitive decline among men but not in women.

Dr. Porter concluded that possible reasons for the higher risk of cognitive decline in men are due to “cultural expectations [regarding] traditional gender roles, and their impact on job choice and socio-economic participation, which can affect men differently in rural China because for their recurrent role as the primary one, i.e. the man is the “breadwinner” and his traditional participation in the work requires greater physical effort and is likely to be exhausting.

bridging the gap

The researchers hope that their findings can "partially fill the knowledge gap" with regard to people of low socioeconomic status, noting that their findings should encourage monitoring of older people "who sleep for long periods and go to bed early, especially the older ones." aged 60-74) and men,” while future studies could look at ways to reduce sleep and adjust schedules that could reduce the risk of dementia and cognitive decline.