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New data appear to consolidate the notion that sleep disturbances may contribute to dementia risk. Image credit: Print Collector/Getty Images.
  • Dementia is a chronic condition that impacts thinking, memory, and other cognitive functions.
  • Researchers are still working to understand what risk factors increase someone’s chances of developing dementia.
  • Data from a recent study suggests that people aged 65 years and older who have trouble falling asleep and who use medication to help them sleep may be at a higher risk for dementia.
  • People at risk for dementia can take steps to improve their sleep quality and sleep habits.

Sleep is an essential component of a healthy lifestyle. Emerging data continue to demonstrate how poor sleep increases health risks. One area of interest is how sleep relates to the risk of developing dementia.

A​ recent study published in the American Journal of Preventative Medicine examined the relationship between different types of insomnia and the risk of developing dementia in adults aged 65 years and over.

The researchers found that people who had trouble falling asleep — which doctors refer to as “sleep-initiation insomnia” — and people who took medications to help with sleep had an increased risk of developing dementia.

However, people who had difficulty falling asleep after waking up early — which clinicians refer to as “sleep-maintenance insomnia” — had a decreased risk of developing dementia.

Dementia affects the way people think and their ability to recall memories. People with dementia may struggle to remember what used to be familiar, and struggle with communicating.

There are different types of dementia, but one of the most common ones is Alzheimer’s disease.

Dr. Jason Krellman, assistant professor of neuropsychology at Columbia University Medical Center, not involved in the study, explained to Medical News Today that “[d]ementia is a significant, usually irreversible decline in cognitive functioning that substantially limits the person’s ability to do their usual daily activities.”

While it is not clear why some people develop dementia and others do not, certain risk factors can increase someone’s chances of developing this condition.

People can modify some of these risk factors, which may decrease their chances of developing dementia.

D​r. Krellman further explained:

“The risk for developing many of these dementia-causing diseases is increased by having certain gene mutations, but in many cases there is no known cause. In general, we know that vascular risk factors, such as high blood pressure, obesity, and smoking increase dementia risk, as do factors such as social isolation and lower levels of education also increase risk.”

Researchers are still working to understand various dementia risk factors, including how sleep quality may affect dementia risk.

T​his particular study used 10 years of national prospective data from the United States. Researchers looked at information from a nationally representative U.S. sample of adults aged 65 years or older. Their final sample included 6,284 adults who did not have dementia at baseline.

The researchers noted that people with dementia often have trouble sleeping. Growing evidence also supports that sleep disturbances can increase someone’s risk for dementia.

T​his study examined three main types of sleep disturbances and the dementia risk associated with them:

  1. sleep-initiation insomnia, which researchers defined as taking 30 minutes or more to fall asleep
  2. sleep-maintenance insomnia, which was trouble getting back to sleep after waking up in the middle of the night
  3. sleep medication usage, which was when people used medications to assist with sleep.

Researchers accounted for several covariates, including age, gender, ethnicity, education, and certain health conditions.

They found that sleep-initiation insomnia and sleep medication usage were associated with an increased risk of dementia.

People who used medications to help with sleep were 30% more likely to develop dementia. People with sleep-initiation insomnia were 51% more likely to develop dementia.

I​n contrast, people with sleep-maintenance insomnia were 40% less likely to develop dementia. The data in this particular area warrant further research.

Study author Dr. Roger Wong, assistant professor of public health and preventive medicine at SUNY Upstate Medical University in Syracuse, NY, explained to MNT:

“The mechanism for decreased dementia risk among those with sleep-maintenance insomnia is unknown, but we write that it may be attributed to these older adults having more time to engage in activities that may preserve or increase their cognitive reserve, thereby decreasing their dementia risk.”

Still, the results indicate the need to look at sleep disturbances as a factor that may influence dementia risk. Dr. Wong further noted that “[t]here is no cure for dementia, and recent pharmaceutical approaches to treating dementia have had mixed results, prompting the importance of preventive approaches to dementia.”

“Therefore, our findings indicate addressing the presence of sleep disturbances should be considered as part of an overall lifestyle change to reduce dementia risk,” he added.

It is important to note that the study had several limitations. First, this study cannot prove that any particular sleep pattern causes or prevents dementia.

Second, researchers only examined three types of sleep disturbances. Further research could explore other sleep problems and their link to dementia risk.

Third, the scoring system researchers used did not measure the start or end of the sleep disturbances. Researchers note that they also only looked at all-cause dementia, but the risk may be different depending on the dementia subtype.

Finally, because of the analysis methods used, there may be a risk of bias due to the number of people who died during the study’s timeframe. Data also relied on self-reporting, and the sample only included adults who were Medicare beneficiaries.

One area of further research is confirming the finding that sleep-maintenance insomnia decreases dementia risk. This will require additional studies and examination of other variables.

The study authors concluded that “[f]uture research is needed to examine other sleep disturbance measures and to explore the mechanisms for decreased dementia risk among older adults with sleep-maintenance insomnia.”

Because sleep is essential to health, people who struggle with certain insomnia types can take steps to get a better night’s sleep.

I​n addition to maintaining good sleep hygiene, such as going to bed at the same time each night and minimizing the use of electronic devices before bedtime, there are other steps that people can take to make it easier to get ti sleep.

Certified sleep technician at Sleep Mattress HQ, Susan Miller shared the following tips with MNT:

Overall, the study sheds light on the need for a good night’s sleep, including as a potential component of decreasing dementia risk.

Dr. Krellman encouraged looking at the data with the following mindset:

“People with insomnia should not assume their sleep problem is a sure sign they will develop dementia, but they should keep in mind what we have known for some time now: That getting enough, good quality sleep helps to promote the health of several organs and systems in the body, including the brain.”