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

Area of Science:

• Cardiovascular Surgery
• Sleep Medicine
• Oxidative Stress Research

Background:

• Oxidative stress, indicated by reactive oxygen species (ROS), plays a role in physiological and pathological processes.
• Sleep and circadian rhythms may impact human ROS concentrations.
• Postoperative recovery is often accompanied by increased oxidative stress.

Purpose of the Study:

• To quantify postoperative venous ROS concentrations in cardiovascular surgery patients.
• To explore associations between ROS levels and subjective/objective sleep parameters.
• To investigate potential links with circadian patterns and patient characteristics.

Main Methods:

• Prospective pilot study involving 15 cardiovascular surgery patients.
• Serial venous blood samples analyzed for ROS using electron spin resonance (ESR) during the first 48 postoperative hours.
• Sleep assessed via validated questionnaires (ISI, PSQI, SF-A) and actigraphy.

Main Results:

• Substantial inter-individual variability in ROS concentrations observed, with no significant circadian pattern.
• No significant association found between mean ROS and overall sleep quality scores (ISI, PSQI, SF-A, actigraphy).
• Higher ROS concentrations significantly correlated with reduced sleep efficiency (r=-0.74, p=0.002) and increased nocturnal wake time (r=0.62, p=0.01) within PSQI subdomains.

Conclusions:

• Electron spin resonance (ESR) is feasible for quantifying venous ROS in postoperative cardiac surgery patients.
• Specific subjective sleep disturbances, namely reduced sleep efficiency and increased nocturnal wakefulness, are associated with elevated postoperative ROS levels.
• Larger studies are needed to validate these preliminary findings on the relationship between sleep quality and oxidative stress post-cardiac surgery.