Following an acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a substantial percentage of patients report the persistence of debilitating symptoms, often grouped in a syndrome termed 'long COVID'. We sought to identify potential pathophysiological mechanisms responsible for the persistence, in some long COVID patients, of symptoms related to fatigue/exercise intolerance (excessive or early fatigue, excessive or early dyspnoea, muscle weakness, and myalgias) more than 2 years after the original infection. Twelve patients who reported persistent symptoms (Long COVID group; 57 +/- 6 years, mean +/- SD), and 14 patients without the symptoms (Control group; 57 +/- 8 years) were evaluated. An extensive series of measurements were performed to identify pathophysiological mechanisms potentially responsible for the symptoms. In long COVID patients, all items evaluating quality of life (SF-36 questionnaire) had lower scores (P < 0.01) compared to control. The habitual level of physical activity, muscle size and strength, maximal aerobic power and the ventilatory thresholds, peak cardiac function, the mechanical efficiency of cycling, pulmonary (VO2)-O-. kinetics, microvascular/endothelial function (hyperemic response in the common femoral artery during passive leg movements), skeletal muscle oxidative metabolism (peak fractional O-2 extraction and muscle (VO2)-O-. recovery kinetics by the repeated occlusions test, by near-infrared spectroscopy) were not different in the two groups. Evidence of ventilatory inefficiency was described in a subgroup of long COVID patients. More than 2 years after the original SARS-CoV-2 infection, a discrepancy was observed between the persistence of debilitating symptoms of fatigue/exercise intolerance and the absence of several investigated pathophysiological mechanisms. The discrepancy may be due to factors that remain to be elucidated.

Persistence of fatigue in the absence of pathophysiological mechanisms in some patients more than 2 years after the original SARS-CoV-2 infection

Favaretto, Thomas;Crisafulli, Ernesto;
2025-01-01

Abstract

Following an acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a substantial percentage of patients report the persistence of debilitating symptoms, often grouped in a syndrome termed 'long COVID'. We sought to identify potential pathophysiological mechanisms responsible for the persistence, in some long COVID patients, of symptoms related to fatigue/exercise intolerance (excessive or early fatigue, excessive or early dyspnoea, muscle weakness, and myalgias) more than 2 years after the original infection. Twelve patients who reported persistent symptoms (Long COVID group; 57 +/- 6 years, mean +/- SD), and 14 patients without the symptoms (Control group; 57 +/- 8 years) were evaluated. An extensive series of measurements were performed to identify pathophysiological mechanisms potentially responsible for the symptoms. In long COVID patients, all items evaluating quality of life (SF-36 questionnaire) had lower scores (P < 0.01) compared to control. The habitual level of physical activity, muscle size and strength, maximal aerobic power and the ventilatory thresholds, peak cardiac function, the mechanical efficiency of cycling, pulmonary (VO2)-O-. kinetics, microvascular/endothelial function (hyperemic response in the common femoral artery during passive leg movements), skeletal muscle oxidative metabolism (peak fractional O-2 extraction and muscle (VO2)-O-. recovery kinetics by the repeated occlusions test, by near-infrared spectroscopy) were not different in the two groups. Evidence of ventilatory inefficiency was described in a subgroup of long COVID patients. More than 2 years after the original SARS-CoV-2 infection, a discrepancy was observed between the persistence of debilitating symptoms of fatigue/exercise intolerance and the absence of several investigated pathophysiological mechanisms. The discrepancy may be due to factors that remain to be elucidated.
2025
exercise intolerance
exercise ventilatory inefficiency
long COVID
oxidative metabolism
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/1170633
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 0
social impact