Deoxygenation Trends and Their Multivariate Association with Self-Reported Fatigue in Post-COVID Syndrome, 2025, Ladek et al

[forestglip]

Deoxygenation Trends and Their Multivariate Association with Self-Reported Fatigue in Post-COVID Syndrome

Anja-Maria Ladek, Marianna Lucio, Andreas Weiß, Thomas Knauer, Helena Sarmiento, Miriam Ilgner, Marie Jakobi, Laura Barteczko, Marion Ganslmayer, Jürgen Rech, Antonio Bergua, Christian Y. Mardin, Bettina Hohberger

Background/Objectives
A relevant subgroup of post-COVID-19 syndrome (PCS) patients suffers from post-exertional malaise (PEM) and cardiovascular or neurological symptoms, impairing daily functioning up to becoming even house- or bedbound.

Recent data suggest that PCS summarizes different subgroups, one of them being characterized by an impaired microcirculation. Thus, the aim of the present study was to investigate local deoxygenation, measured with non-invasive near-infrared regional spectroscopy (NIRS), and its association with self-reported fatigue in patients with PCS compared to controls in light exercise.

Methods
150 participants (100 PCS patients and 50 controls) were recruited. PEM was assessed using FACIT, Chalder, and Bell scoring and Canadian Criteria. NIRS was used to measure local oxygenation while kneading a stress ball and during recovery.

Results
PCS patients showed fatigue scores of 30 (Bell score), 20.6 (FACIT fatigue score), and 9.914 (Chalder fatigue score). Decreased deoxygenation peaks at the start of exercise were observed in patients with PCS, compared to controls (p = 0.0002).

Multivariate analysis identified a subgroup, showing an association between strong fatigue and restricted oxygenation dynamics.

Conclusions
NIRS could be a potential tool to assess deoxygenation deficits even in moderate to severely impaired PCS patients using light exercise protocols.

Link | PDF (Biomedicines) [Open Access]

 

[Utsikt]

Participants were then asked to vigorously knead a stress ball. As the curve variance is already expected to be high, and oxygenation changes from the baseline occur delayed in submaximal exercise [20,29], time was counted from the first changes from the baseline. After 60 s of the first oxygenation changes from the baseline, the participant was asked to suddenly stop and remain relaxed. Oxygenation changes continued to be measured for 2 min after the exercise.

I’m not sure I would characterise this as «light exercise» as they do in the abstract. But it seems to be quite similar to the thumb exertion that Fluge and Mella have been using.

 

[Hutan]

The abstract is light on the key issue of whether they found deoxygenation, with no mention of reduced oxygenation immediately following exercise.

Decreased deoxygenation peaks at the start of exercise were observed in patients with PCS, compared to controls (p = 0.0002).

Is the paper worth reading? Temporary deoxygenation would fit with some of the recent protein expression findings; it's an attractive theory.