jcedernaes.bsky.social
@jcedernaes.bsky.social
(9/9) Big thanks to co-authors including my PhD candidate Anastasia Grip, and our fantastic collaborators at Uppsala university @uu.se – especially @christianbenedict.bsky.social, @uio.no University of Oslo, Stockholm University, & Sahlgrenska University Hospital!

PR: www.uu.se/en/press/pre...
May 8, 2025 at 10:52 AM
(8/9) Optimal sleep (≥7 hours/night) is critical for heart health, emphasized by recent @American_Heart guidelines.

Our findings underscore the need to consider sleep duration, daily sample timing and physical exercise for enhanced precision medicine & #biomarker work
May 8, 2025 at 10:52 AM
(7/9) Importantly, we found that even our rather short-term intervention of “moderate” sleep restriction 💤elevated pro-#inflammatory proteins (e.g., IL-27, LGALS9)—previously linked to higher #cardiovascular disease risk ❤️‍🩹 in large-scale studies.
May 8, 2025 at 10:52 AM
Indeed, UK biobank data indicates that higher levels of physical activity can offset some, but importantly not all, of the adverse mortality effects of sleep restriction, on for example cardiovascular mortality bjsm.bmj.com/content/56/1...
Sleep and physical activity in relation to all-cause, cardiovascular disease and cancer mortality risk
Objectives Although both physical inactivity and poor sleep are deleteriously associated with mortality, the joint effects of these two behaviours remain unknown. This study aimed to investigate the j...
bjsm.bmj.com
May 8, 2025 at 10:52 AM
(5/9) We have previously found that exercise under sleep restricted conditions may put an extra burden on your heart cells, at least in the short term (but exercise can also offset some, but not all negative effects of poor sleep patterns:

www.sciencedirect.com/science/arti...
Effects of curtailed sleep on cardiac stress biomarkers following high-intensity exercise
Physical exercise—especially at high intensity—is known to impose cardiac stress, as mirrored by, e.g., increased blood levels of cardiac stress bioma…
www.sciencedirect.com
May 8, 2025 at 10:52 AM
(4/9) 🏃‍♂️ #Exercise boosted beneficial "exerkines" (e.g., IL-6, BDNF), but fewer proteins rose immediately post-exercise in blood after restricted sleep (just over 4 hrs/night), suggesting that sleep loss may blunt some exercise benefits.
May 8, 2025 at 10:52 AM
(3/9) 🕣 We discovered clear time-of-day patterns for key proteins related to #cardiometabolic health (some of course previously known) - important to consider, as clinical measurements typically happen in the morning, also for biomarker studies.
May 8, 2025 at 10:52 AM
(2/9) With amazing teamwork together with first-author postdocs Luiz Brandão & Lei Zhang, we studied how sleep duration, physical exercise, and time-of-day impact ~90 blood #proteins connected to #heart health, measured in healthy young men.
May 8, 2025 at 10:52 AM
As another line of supportive evidence in humans, disruption of slow wave sleep increases CSF levels of #amyloid-β in healthy humans:

academic.oup.com/brain/articl...

And earlier in my thread:

Supporting causality, disrupted sleep *4 decades* earlier increases the risk of dementia/AD in humans
February 21, 2025 at 4:34 PM
Thank you for your question. There is a lot of evidence that disrupted sleep causally promotes #neurodegeneration.

Many reviews cover this – here's our
www.sciencedirect.com/science/arti...

As an example in humans, one night of sleep loss disrupts brain amyloid levels www.pnas.org/doi/abs/10.1...
Candidate mechanisms underlying the association between sleep-wake disruptions and Alzheimer's disease
During wakefulness, extracellular levels of metabolites in the brain increase. These include amyloid beta (Aβ), which contributes to the pathogenesis …
www.sciencedirect.com
February 21, 2025 at 4:34 PM
Thanks to great teamwork with Christian Benedict!
February 21, 2025 at 5:02 AM
Here is the response by the authors of the original 2024 report, "Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission", by Livingston et al.: www.thelancet.com/journals/lan...

In response to our letter: www.thelancet.com/journals/lan...
Reflections on The Lancet's Commission on dementia prevention, intervention, and care – Authors' reply
We are pleased that our 2024 Lancet Commission's1 discussion of dementia risk has prompted international interest. Within it, we have been transparent about the assumptions behind our new population a...
www.thelancet.com
February 21, 2025 at 5:02 AM
The report by Livingston et al. is obviously very impressive, but we believe that there is sufficient evidence to consider disrupted and/or misaligned sleep as important and often modifiable risk factors when aiming to help prevent the rising prevalence of dementia in the decades to come.
February 21, 2025 at 5:02 AM
We of course need more studies, but as I have previously highlighted, we also have long-term follow-up to indicate that disrupted sleep increases the risk of dementia over for example 40 years:

www.sciencedirect.com/science/arti...

This argues against reverse causation as Livingston et al. favor.
Self-reported sleep disturbance is associated with Alzheimer's disease risk in men
To study the association between self-reported sleep disturbances and dementia risk.Self-reported sleep disturbances and established risk factors for …
www.sciencedirect.com
February 21, 2025 at 5:02 AM
Livingston et al use a brain imaging study with lack of association findings, to claim that they sleep duration does not impact brain health. But that study is an example of a rather short follow-up study (~2.5 years), and "only" used brain imaging, as opposed to actual clinical diagnostics.
February 21, 2025 at 5:02 AM
In their report, Livingston et al. focused primarily on sleep duration, and claimed there wasn't evidence on quality.

But as I have highlighted earlier (on X at the time of the publication) most sleep disorders — such as the highly prevalent insomnia — are based on subjectively impaired sleep.
x.com
x.com
February 21, 2025 at 5:02 AM
Further meta-analytical evidence that shift work – which misaligns sleep and often worsens its quality – increases the risk of dementia:

- Hai et al. 2022 journals.sagepub.com/doi/full/10....
- (this one from this year), by Jones et al. www.sciencedirect.com/science/arti...
Does Long-Term Shift Work Increase the Risk of Dementia? A Systematic Review and Meta-Analysis - Yang Hai, Ying Xue, Yu-hong Wang, 2022
Background: Shift work is associated with impaired sleep quality and disrupted circadian rhythms, but the way in which it increases the risk of dementia remains...
journals.sagepub.com
February 21, 2025 at 5:02 AM
There is also quite convincing meta-analytical evidence that #shiftwork increases the future risk of dementia:

- Gao et al. 2023 www.sciencedirect.com/science/arti...
- Wang et al., 2022, for night shifts www.frontiersin.org/journals/neu...
- Lee et al. 2023 www.frontiersin.org/journals/pub...
Impact of shift work on dementia: a systematic review and dose-response meta-analysis
Although shift work has been reported as having a link to dementia, evidence remains inconsistent, and a comprehensive dose-response meta-analysis of …
www.sciencedirect.com
February 21, 2025 at 5:02 AM
These meta-analyses find a 50% or higher risk of #Alzheimer's disease in those with sleep disturbances. And they also have quite large sample sizes: n=246,786 and 198 232.
- academic.oup.com/sleep/articl... and
- www.sciencedirect.com/science/arti...
Validate User
academic.oup.com
February 21, 2025 at 5:02 AM
The meta-analyses on how sleep disturbances can impact the risk of dementia and AD have in general quite long follow-up, which is an important aspect to try to rule out whether disrupted sleep occurred at the same time as say AD started: ~9.5 and ~12.1 years.
February 21, 2025 at 5:02 AM