OLDER women who experience a change to their sleep pattern could be doubling their risk of dementia, warns new research.
Women in their 80s who experience increasing sleepiness during daytime over a five-year period are at twice the risk of developing the debilitating condition, according to the findings.
Women who feel increasingly sleepy during the daytime could be at increased risk of dementia[/caption]
The American research team say their study, published by the journal Neurology, doesn’t prove that daytime sleepiness causes dementia, but it does show a link between the two.
Study author Dr Yue Leng, of the University of California, San Francisco, said: “Sleep is essential for cognitive health, as it allows the brain to rest and rejuvenate, enhancing our ability to think clearly and remember information.
“However, little is known about how changes in sleep and cognition are connected over time and how these changes relate to dementia risk in the later decades of life.
“Our study found that sleep problems may be intertwined with cognitive ageing and may serve as an early marker or risk factor for dementia in women in their 80s.”
The study involved 733 female participants with an average age of 83 who did not have mild cognitive impairment or dementia at the start.
During the five-year study period, 164 participants (22 per cent) developed mild cognitive impairment and 93 participants (13 per cent) developed dementia.
The participants wore wrist devices to track their sleep and circadian rhythm patterns for three days at the start and end of the study.
The research team looked at the changes in the duration and quality of their sleep at night, daytime napping and circadian rhythm patterns.
Circadian rhythms are the body’s natural 24-hour internal clock, which tell you when to wake up, feel alert, get sleepy, or go to bed based on cues like light, darkness, and your routine.
After five years, researchers observed “large changes” in sleep patterns in more than half of the participants (56 per cent).
The researchers found that participants fell into three groups:
- Stable sleep or small improvements in sleep (44 per cent)
- Declining night-time sleep (35 per cent)
- Increasing sleepiness (21 per cent)
Worsening sleep at night-time included reductions in sleep quality and duration, moderate increases in napping and worsening circadian rhythms.
Bad circadian rhythms happen when your body’s internal clock is out of sync with its natural schedule, making you feel tired during the day, struggle to sleep at night, or feel generally unwell.
People who experienced increasing sleepiness slept for longer during the day and night-time and had worsening circadian rhythms.
The researchers then looked at how those changes were linked to the risk of developing dementia.
Of those in the stable sleep group, 8 per cent developed dementia.
Meanwhile, in the declining night-time sleep group, 15 per cent developed dementia and in the increasing sleepiness group, 19 per cent got the memory-robbing condition.
Ways to lower your risk of dementia
There are things you can do to reduce your own risk of developing dementia, including Alzheimer’s.
No single behaviour is guaranteed to prevent dementia – but there’s lots of evidence to suggest that making tweaks to your lifestyle choices could affect your risk.
Dementia risk is lowest in people who have healthy behaviours in mid-life – from the age of 40 to 65 – according Alzheimer’s Society.
Here are a few easy changes you can make:
- Exercise regularly to boost your heart health and circulation and help maintain a healthy weight.
- Drink less alcohol – try to have no more than 14 units of alcohol a week, about one pint of beer or a small glass of wine each day. If you regularly drink much more than this, you are increasing your risk of damage to your brain and other organs, and so increasing your risk of dementia.
- Don’t smoke – it does a lot of harm to the circulation of blood around the body, particularly the blood vessels in the brain, as well as the heart and lungs.
- Engaging in social activities to help to build up your brain’s ability to relieve stress and improve your mood – depression and social isolation have both been linked to dementia.
- Manage health conditions, such as high blood pressure, high cholesterol or diabetes, which can increase the risk of getting dementia.
- Protect your eyesight and hearing – vision loss increases a person’s risk of developing dementia. The same goes for hearing loss, which can also be an early symptom of dementia.
- Wear a helmet – as traumatic brain injuries can start a process in the brain where the substances that cause Alzheimer’s disease build up around the injured area.
Source: Alzheimer’s Society
After adjusting for age, education and race, and health factors – such as diabetes and high blood pressure – the researchers found that participants grappling with increasing sleepiness group had double the risk of dementia compared to those in the stable sleep group.
No association with the condition was found in the declining night-time sleep group.
Dr Leng said: “We observed that sleeping, napping and circadian rhythms can change dramatically over only five years for women in their 80s.”
She added: “This highlights the need for future studies to look at all aspects of daily sleep patterns to better understand how changes in these patterns over time can be linked to dementia risk.”
It’s not the first time researchers have looked at people’s sleep patterns to gain insight into dementia.
Australian scientists recently found that people who went to sleep before 9pm and slumbered for over nine hours had a 60 per cent higher risk of the brain-robbing disease, compared to people people who had a “normal bedtime” and slept less.
Previous studies have also linked frequent nightmares to an increased risk of dementia.
