Recent research has highlighted a significant connection between irregular sleep patterns and an increased risk of dementia. This groundbreaking study, published in the journal Neurology, involved 88,094 participants who were monitored for their sleep cycles using wrist devices over a period of seven days.
These participants, averaging 62 years in age, provided invaluable data that allowed researchers to calculate the regularity of their sleep and the probability of being in the same sleep state (asleep or awake) at any two time-points, 24 hours apart. The study’s findings are alarming yet insightful. Participants were scored on a scale of 0 to 100 based on their sleep regularity, with 100 indicating perfect regularity and zero representing complete irregularity.
Those in the lowest 5% had an average score of 41, while the highest 5% averaged at 71, with the overall average being 60. Over an average follow-up period of seven years, 480 participants developed dementia. The research revealed that individuals with irregular sleep patterns were 53% more likely to develop dementia than those with midrange scores.
Interestingly, having the most regular sleep pattern did not significantly decrease dementia risk compared to the group in the middle. This study raises critical questions about the relationship between sleep and brain health. Dr. Steven Feinsilver, the director of sleep medicine at Northwell Lenox Hill Hospital in New York, who was not involved in the study, points out the complexity of this relationship. He questions whether poor sleep leads to dementia or if dementia causes poor sleep.
Feinsilver emphasizes the importance of sleep for brain health, noting that regularity in wake time is more crucial than when one goes to sleep. The implications of this research extend beyond dementia. Irregular sleep patterns have also been associated with cardiovascular disease, metabolic disorders, depression, and atherosclerosis.
For instance, a 2019 study in Diabetes Care reported that lack of a regular bedtime/wake-up schedule could increase the risk of obesity, high cholesterol, hypertension, high blood sugar, and other metabolic disorders. Each hour of variability in sleep time could increase the risk by 27%. Furthermore, studies in 2021 and 2023 linked irregular sleep patterns to mood disorders, depression, and atherosclerosis. Â
The Centers for Disease Control and Prevention recommend that most adults sleep seven or more hours per night. The National Institutes of Health suggest several strategies for improving sleep patterns, such as maintaining a consistent bedtime and wake-up time, creating a quiet and soothing sleep environment, and engaging in calming activities before bedtime. Â
Dr. Scott Kaiser, a geriatrician and the director of geriatric health for the Pacific Neuroscience Institute in Santa Monica, California, also not involved in the study, underscores the importance of sleep hygiene. He points out that while sleep aids can be helpful, they do not always provide restorative sleep and can have significant side effects. Kaiser advocates for cognitive behavioral therapy as the best approach to combat insomnia. Â
In conclusion, this study underscores the critical importance of maintaining regular sleep patterns for overall health and particularly for reducing the risk of dementia. It highlights the need for further research into the complex relationship between sleep and brain health and emphasizes the role of good sleep hygiene in preventing various health issues.Â
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Yiallourou, S. R., Cribb, L., Cavuoto, M. G., Rowsthorn, E., Nicolazzo, J., Gibson, M., … Pase, M. P. (2024). Neurology, 102(2). doi:10.1212/wnl.0000000000208029
