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Upstate study shows links between insomnia and dementia

Upstate Medical University Professor Roger Wong was worried that his father kept waking up in the middle of the night. His father had just turned 65 and Wong wanted to know how his sleep disturbances could impact his cognitive health as he aged.

Not finding a clear answer in any existing literature, Wong decided to study the issue himself.

Wong’s study “Sleep Disturbances and Dementia Risk in Older Adults: Findings From 10 Years of National U.S. Prospective Data,” was published in the American Journal of Preventive Medicine. The study is the first of its kind to use a nationally representative U.S. population to study the issue. It is co-authored by Margaret Lovier, a student in the MPH program at the time of the study who is now a medical student.

“Additionally, this research is the first to examine how longitudinal sleep disturbance measures are associated with dementia risk,” said Wong, noting that evidence suggests sleep disturbances are on the rise.

Wong looked at 10 years of data—2011 to 2020—for adults, aged 65 and older, and examined the association between dementia and three measures of sleep disturbances—sleep-initiation insomnia (trouble falling asleep in 30 minutes), sleep-maintenance insomnia (trouble falling asleep after waking up early), and sleep medication usage.

Wong, PhD, MPH, MSW, found that sleep-initiation insomnia and sleep medication usage significantly increased dementia risk, whereas sleep-maintenance insomnia significantly decreased dementia risk.

Wong said sleep disturbances are a public health problem that needs to be addressed.

Wong, an assistant professor of public health and preventive medicine, said previous studies were primarily cross-sectional, meaning only one point in time, and focused on specific geographical regions. He said it is common for sleeping patterns to change as people get older due to aging-related processes.

He added that he expected the findings about sleep-initiation insomnia and use of sleep aids to increase risk but was surprised by the finding that sleep-maintenance insomnia decreased risk. While the true cause is unknown, he posits that these adults may have more time to engage in activities that preserve or increase their cognitive reserve, which decreases dementia risk.

For example, his father reads the newspaper or gardens when he wakes up in the middle of the night, two activities that stimulate the brain and may protect it.

“He is still waking up in the middle of the night, but it is reassuring to see in my research that it may not necessarily increase his risk for dementia,” he said.

Wong said the study’s results indicate that prioritizing good sleep is an important lifestyle component to consider when trying to reduce dementia risk.

“There’s no cure for dementia right now and we have very limited treatment options that generally do not improve symptoms, so there is a lot of focus on prevention,” he said.

“Typically, when people ask me how to prevent dementia, I would tell them to look at their diet, physical activities, social activities, and substance use, especially cigarette smoking. But there is less talk about sleep,” Wong said.

“Sleep is going to be added to my list because there is emerging evidence that we should also include sleep as part of an overall healthy lifestyle.”

Caption: The study was published by medical student Margaret Anne Lovier, MPH, and Roger Wong, PhD, MPH, MSW, collaborated on the sleep-dementia study.