Evidence map›Paper›PMID 42225266›Full record

ArticleJournal of sleep research2026

Association Between Sleep Quality and Oxidative Stress in Postoperative Cardiovascular Patients-A Pilot Study.

K Krawczyk, D Riemann, E Schleicher, A Günther, A Ayekoi, M Czerny, J S Pooth, T Böhmerle, B Feige, J Sahlmann and 1 more

Abstract read
In one paragraph

Article in Journal of sleep research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

K KrawczykDepartment of Cardiovascular Surgery, University Hospital Freiburg, Freiburg im Breisgau, Germany.
D RiemannFaculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.ORCID https://orcid.org/0000-0002-1968-6220
E SchleicherInstitute of Physical Chemistry, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
A GüntherInstitute of Physical Chemistry, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
A AyekoiInstitute of Physical Chemistry, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
M CzernyDepartment of Cardiovascular Surgery, University Hospital Freiburg, Freiburg im Breisgau, Germany.
J S PoothFaculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.ORCID https://orcid.org/0000-0001-6882-2009
T BöhmerleDepartment of Cardiovascular Surgery, University Hospital Freiburg, Freiburg im Breisgau, Germany.
B FeigeFaculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.ORCID https://orcid.org/0000-0002-9436-1258
J SahlmannFaculty of Medicine, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
F BeyersdorfDepartment of Cardiovascular Surgery, University Hospital Freiburg, Freiburg im Breisgau, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Oxidative stress contributes to numerous physiological and pathological processes, and sleep behaviour as well as circadian rhythms may influence reactive oxygen species (ROS) concentrations in humans. This prospective pilot study quantified postoperative venous ROS concentrations in patients undergoing cardiovascular surgery and explored associations with subjective and objective sleep parameters, circadian patterns and patient characteristics. Fifteen patients undergoing cardiovascular surgery at the University Medical Center Freiburg were monitored during the first 48 postoperative hours. Serial venous blood samples were analysed for ROS concentrations using electron spin resonance. Sleep was assessed using validated questionnaires, including the Insomnia Severity Index, Pittsburgh Sleep Quality Index and Schlaffragebogen-A (SF-A), as well as actigraphy. Additional clinical data were recorded. Venous ROS concentrations showed substantial inter-individual variability but no significant circadian pattern. Mean postoperative ROS concentrations were not significantly associated with ISI scores, PSQI global score, SF-A parameters or objective actigraphic sleep measures. Among PSQI subdomains, however, higher ROS concentrations were significantly associated with reduced sleep efficiency (r = -0.74, p = 0.002) and longer nocturnal wake time (r = 0.62, p = 0.01), while shorter sleep duration showed a trend-level association (r = -0.49, p = 0.07). These findings demonstrate the feasibility of electron spin resonance-based venous ROS quantification in postoperative cardiac surgery patients. Specific subjective sleep parameters, particularly reduced sleep efficiency and increased nocturnal wake time, may be associated with higher postoperative ROS concentrations. Larger studies are warranted to confirm these exploratory findings.

Indexed as

Cardiac Surgical ProceduresCardiovascular DiseasesOxidative StressReactive Oxygen SpeciesSleep QualityActigraphyAgedCircadian RhythmFemaleHumansMaleMiddle AgedPilot ProjectsPostoperative PeriodProspective StudiesSleep DurationReactive Oxygen Speciesperioperative periodreactive oxygen speciessleep pattern

Identifiers

PMID42225266
PMCPMC13619085

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.