EMBARGOED FOR RELEASE UNTIL 4 PM ET, December 13, 2023
Very Irregular Sleep Linked to Higher Risk of Dementia
MINNEAPOLIS 鈥 People who have very irregular sleep patterns may have a higher risk of dementia than those who have more regular sleep patterns, according to new research published in the December 13, 2023, online issue of , the medical journal of the 好色先生. The study does not prove that sleep irregularity causes dementia. It only shows an association. Sleep regularity is how consistent you are at going to sleep and waking up at the same time each day. 鈥淪leep 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,鈥 said study author Matthew Paul Pase, PhD of Monash University in Melbourne, Australia. 鈥淥ur findings suggest the regularity of a person鈥檚 sleep is an important factor when considering a person鈥檚 risk of dementia.鈥 The study involved 88,094 people with an average age of 62 in the United Kingdom. They were followed for an average of seven years. Participants wore a wrist device for seven days that measured their sleep cycle. Researchers then calculated the regularity of participants鈥 sleep. They determined the probability of being in the same sleep state, asleep or awake, at any two time points 24 hours apart, averaged over seven days. A person who sleeps and wakes at the exact same times each day would have a sleep regularity index of 100, while a person who sleeps and wakes at different times every day would have a score of zero. Researchers then looked at medical data to identify which participants developed dementia and found 480 people developed the disease. Researchers found links between sleep regularity scores and risk of dementia. Compared to those with an average sleep regularity index, the risk of dementia was highest for people who had the most irregular sleep. People in the lowest fifth percentile had the most irregular sleep with an average score of 41. Those in the highest 95th percentile had the most regular sleep with an average score of 71. People between these two groups had an average sleep regularity score of 60. After adjusting for age, sex and genetic risk of Alzheimer鈥檚 disease, researchers found that those with the most irregular sleep were 53% more likely to develop dementia than people in the middle group. For people with the most regular sleep, researchers found they did not have a lower risk of developing dementia than people in the middle group. 鈥淓ffective sleep health education combined with behavioral therapies can improve irregular sleep patterns,鈥 Pase said. 鈥淏ased 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.鈥 Pase said that although they adjusted for several factors that can affect the risk of dementia, they cannot rule out that another unknown factor may play a role in the association between sleep regularity and dementia. The study was funded by the National Health and Medical Research Council of Australia. Learn more about dementia at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and . When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.