Disrupted sleep damages blood vessels in brain and may increase dementia risk

Medical Xpress / University of Toronto / Brain ^ | July 30, 2025 | Nadia Norcia / Mahnoor Hamid et al

[ConservativeMind]

A new study reveals that fragmented sleep causes cellular damage to the brain's blood vessels, providing further evidence to suggest that sleep disruption predisposes the brain to dementia.

The research is the first to offer cellular and molecular evidence that sleep disruption directly causes damage to brain blood vessels and blood flow.

"We found that individuals who had more fragmented sleep, such as sleeping restlessly and waking up a lot at night, had a change in their balance of pericytes—a brain blood vessel cell that plays an important role in regulating brain blood flow and the entry and exit of substances between the blood and the brain," said Andrew Lim.

"This in turn was associated with a more rapid decline in cognitive function in the decade leading up to their death."

The researchers applied wearable smartwatch-like sensors to the research subjects—more than 600 older adults—to measure their sleep and used new gene sequencing technologies to measure levels of pericytes in the brain. The research participants subsequently passed away and donated their brains for analysis.

"We know that in some individuals, sleep disruption can precede the onset of cognitive impairment by years, with emerging evidence suggesting a bidirectional link between sleep disruption and Alzheimer's disease," adds Lim.

The study's findings suggest:

—Sleep fragmentation may be an important factor leading to brain blood vessel injury

—Pericytes may be particularly important in mediating these effects

—Targeting sleep fragmentation may be a means of improving brain vascular health

—Targeting pericytes may be a mechanism of preventing the deleterious effects of sleep fragmentation on brain blood flow and subsequently on Alzheimer's disease and other dementias

"This study raises the possibility that changes in pericytes may be a mechanism linking sleep fragmentation with small vessel disease and cognitive decline," says Lim.

[ConservativeMind]

Minimize fragmented sleep, as much as possible, to reduce dementia risk.

[ConservativeMind]

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[linMcHlp]

bkmk

[ProtectOurFreedom]

How do I know if I have fragmented sleep?

• Frequent Awakenings: Waking up multiple times during the night, even briefly, more than 2-3 times.
• Difficulty Staying Asleep: Trouble returning to sleep after waking, taking longer than 20-30 minutes.
• Non-Restorative Sleep: Feeling tired, groggy, or unrefreshed upon waking despite spending enough time in bed (7-9 hours for most adults).
• Daytime Symptoms: Excessive daytime sleepiness, irritability, difficulty concentrating, or low energy, suggesting poor sleep quality.
• Physical Signs: Snoring, gasping, or leg twitching during sleep, which may indicate conditions like sleep apnea or restless leg syndrome.
• Sleep Tracking: Using a sleep journal or wearable device showing multiple awakenings or reduced deep/REM sleep stages.
• External Disruptions: Noticing disturbances like noise, light, or partner movement that wake you frequently.
• Medical Indicators: Symptoms like frequent urination, heartburn, or pain that disrupt sleep; consult a doctor to rule out underlying conditions.
• Persistent Issues: If you suspect fragmented sleep, track patterns for 1-2 weeks and consult a sleep specialist for diagnosis, possibly using a sleep study.

How to minimize fragmented sleep...

• Optimize Sleep Environment: Keep bedroom dark, quiet, cool (60-67°F). Use blackout curtains, earplugs, white noise, comfortable bedding.
• Consistent Schedule: Same bedtime and wake-up daily, even weekends, to stabilize circadian rhythm.
• Limit Stimulants: Avoid caffeine, nicotine, alcohol near bedtime; caffeine lasts 6-8 hours, alcohol disrupts deep sleep.
• Manage Stress: Use deep breathing, meditation, or journaling to reduce anxiety causing awakenings.
• Regulate Screens: Limit blue light 1-2 hours before bed; use filters or glasses to support melatonin.
• Address Medical Issues: Consult doctor for sleep apnea, restless leg syndrome, or reflux; snoring may indicate apnea (10-30% adults).
• Limit Naps: Keep naps short (20-30 min), before 3 PM to avoid nighttime disruption.
• Diet and Exercise: Light dinner 2-3 hours before bed, regular exercise (30 min most days), avoid late workouts.
• Bedtime Routine: Calming activities like reading or bathing to signal sleep time.
• Limit Fluids: Reduce liquids 2 hours before bed to minimize bathroom trips; consult doctor for frequent urination.
• Persistent Issues: Track sleep with journal or device, consult specialist for CBT-I if needed.

[sauropod]

Bkmk

[Texas Eagle]

Then how do you explain Joe Biden? Nobody got more sleep than that guy.

[Recompennation]

What comes first the chicken or the egg.,,

[phil00071]

I’ve tried all these approaches, and none of them are effective in dealing with my fragmented sleep. I think the medical community should focus on such issues as hormonal changes, chemical changes in the brain and body as we age, and simulate factors, but they keep spewing the same old “solutions.”

[bunkerhill7]

Our bed was broken into fragments by sex.
Now we have fragmented sex.

[ckilmer]

try 5 grams of creatine and melatonin before bed.

[Ronaldus Magnus III]

Disrupted sleep also damages alarm clocks, cats, phones, and relationships.

[Bratch]

[KC_for_Freedom]

I had been waking up to five times a night and my urologist was convinced that this was due to an enlarged prostate. Not so, my respiration got worse. I developed a-fib which did not respond to multiple ablations. I had two instances of sub-dural hematomas. And finally went to emergency with respiratory failure. They put me on oxygen and a full face mask ( I was a mouth breather) and suddenly I slept through the night. Later a sleep study showed that I had obstructive sleep apnea and had it for a long time.

My recommendation is to rule out sleep apnea if you have disruptive sleep. My case had zero other symptoms. I have been on a ventilator and oxygen now for 3 years. Sleeping well and feeling better. Staying retired but this solved the issue that led to retiring from teaching.

[Lazamataz]

try 5 grams of creatine and melatonin before bed.

I first read that as '5 grams of cocaine'.

That would NOT help sleep.

[sauropod]

All I can say is, that as I age, getting 7 - 8 hours a night is really important. My CPAP machine aids that.

[Flaming Conservative]

I made a huge mistake when I didn’t crate train our 2 mini dachshunds. They sleep with us and they consider our bed to be theirs. They are particularly attached to me, and the male, especially so. They insist on gluing themselves to me when they sleep, and it does disturb my sleep. If I move over a bit, they move with me. I regret not training them to sleep in a crate, because I know I would sleep much better.

[redfreedom]

I tend to disregard any study, most are BS designed to make an outright lie appear to be the truth. Especially when it comes to climate change, medical or politics.

If there’s an agenda, a study will be created to support it.

[Hyman Roth]

I drink one shot of wild turkey before bed. Sleep like a baby

[ckilmer]

Agree.

Lately, I’ve also added a scoop of micellar casein protein. That seems to help, too.

[PIF]

As a commercial salmon fisherman for 30 years - there was hardly any nights when my sleep was not interrupted - so ll my brain blood vessels must be burst - if that study had a shred of validity at all.