Clinical characterization of dysautonomia in long COVID-19 patients | Scientific Reports (nature.com)
39 participants were included from December 2020 to January 2021 for assessment by the Department of physical medicine to enhance their physical capabilities:
12 participants with COVID-19 diagnosis and fatigue,
15 participants with COVID-19 diagnosis without fatigue and
12 control participants without COVID-19 diagnosis and without fatigue.
Heart rate variability (HRV) during a change in position is commonly measured to diagnose autonomic dysregulation. In this cohort, to reflect HRV, parasympathetic/sympathetic balance was estimated using the NOL index, a multiparameter artificial intelligence-driven index calculated from extracted physiological signals by the PMD-200 pain monitoring system.
Repeated-measures mixed-models testing group effect were performed to analyze NOL index changes over time between groups.
A significant NOL index dissociation over time between long COVID-19 participants with fatigue and control participants was observed (p = 0.046).
A trend towards significant NOL index dissociation over time was observed between long COVID-19 participants without fatigue and control participants (p = 0.109).
No difference over time was observed between the two groups of long COVID-19 participants (p = 0.904).
Long COVID-19 participants with fatigue may exhibit a dysautonomia characterized by dysregulation of the HRV, that is reflected by the NOL index measurements, compared to control participants.
Dysautonomia may explain the persistent symptoms observed in long COVID-19 patients, such as fatigue and hypoxia.