Irregular sleep may increase the risk of dementia, according to new research from December 13, 2023. The study in Neurology® suggests that people with inconsistent sleep patterns are more likely to develop dementia. However, it doesn’t prove that irregular sleep causes dementia, only that there’s a connection. Sleep regularity means sticking to the same bedtime and wake-up time every day.
Study author Matthew Paul Pase, Ph.D. of Monash University in Melbourne, Australia, said, “Sleep health recommendations often focus on getting the recommended amount of sleep, which is seven to nine hours a night, but there is less emphasis on maintaining regular sleep schedules. Our findings suggest the regularity of a person’s sleep is important when considering a person’s risk of dementia.”
A study in the UK followed 88,094 people, averaging 62 years old, for seven years. They wore a wrist device to measure their sleep patterns. The researchers calculated sleep regularity based on participants’ consistency in their sleep cycles.
They used a sleep regularity index, with 100 being perfect consistency and zero being highly irregular. After analyzing medical data, they discovered that 480 participants developed dementia. The study revealed a connection between irregular sleep and a higher risk of dementia. Those with the most irregular sleep had the highest dementia risk compared to those with average sleep regularity.
The study categorized people based on their sleep regularity scores. The lowest fifth percentile had the most irregular sleep (average score of 41). In contrast, the highest 95th percentile had the most regular sleep (average score of 71), and those in between scored an average of 60.
After considering age, sex, and genetic Alzheimer’s risk, researchers found that those with the most irregular sleep were 53% more likely to develop dementia than the middle group. Surprisingly, people with the most regular sleep did not show a lower risk of dementia compared to the middle group.
Pase said, “Effective sleep health education combined with behavioral therapies can improve irregular sleep patterns. Based on our findings, people with irregular sleep may only need to improve their sleep regularity to average levels, compared to very high levels, to prevent dementia. Future research is needed to confirm our findings.”
Pase mentioned that, despite considering various factors affecting dementia risk, they can’t rule out the possibility of an unknown factor influencing the link between sleep regularity and dementia.
The study received funding from Australia’s National Health and Medical Research Council.
The American Academy of Neurology (AAN) is the largest association of neurologists and neuroscience professionals globally, boasting 40,000 members. The AAN is committed to providing top-notch, patient-focused neurological care. Neurologists and specialized doctors diagnose and treat disorders of the brain and nervous system, including Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease, and epilepsy.
This research underscores the importance of sleep regularity and its potential role in dementia risk. The findings provide valuable insights into the relationship between sleep patterns and cognitive health, emphasizing the need for further exploration in this field.
Journal reference:
- Stephanie R. Yiallourou, Lachlan Cribb, et al., Association of the Sleep Regularity Index With Incident Dementia and Brain Volume. Neurology. DOI: 10.1212/WNL.0000000000208029.