Abstract:
Background: Exercise intolerance is a prominent aetiology of long-COVID syndrome, yet the mechanisms causing the debilitation remain unknown. Vascular dysfunction is thought to play a role, hence we sought to determine if there is a relationship between exercise capacity and vascular function in COVID survivors.
Methods: Forty-two COVID-19 survivors; 33 self-identified long-COVID sufferers and 9 recovered controls (40.7±11.8 vs 40.2±14.5 years, both 67% female) underwent extensive phenotyping >3 months post-infection. Blood pressure (BP) and heart rate were measured (automated BP device), before carotid, femoral, and radial tonometry (carotid–femoral pulse wave velocity; [cPWV], augmentation index; [AIx]) were performed to assess vascular stiffness. Endothelium-dependent and independent dilatation were assessed via brachial artery flow-mediated dilation ([FMD]; Doppler-ultrasound) in response to reactive hyperaemia and glyceryl trinitrate respectively. Cardiopulmonary exercise testing determined peak oxygen uptake (VO2).
Results: Long-COVID sufferers had reduced VO2 peak compared to controls (26.5±7.0 vs 32.8±11.3 ml/min/kg, p= 0.045). Haemodynamic and vascular function were similar between groups, though there was a medium effect size (ES) for between group differences in cPWV (6.6±1.2 vs 6.1±0.9 m/sec, p=0.20; ES 0.44) and AIx (14±15% vs 4±16%, p=0.11; ES 0.67). VO2 peak was inversely correlated with AIx (r = -0.60, p<0.001) and cPWV (r = -0.55, p<0.001). There was no significant association between endothelial function and exercise capacity parameters.
Conclusions: Lower VO2peak measures in long-COVID participants were strongly associated with increased AIx and cPWV. These findings indicate the need for further longitudinal investigations to determine if these manifestations persist and impact long-term cardiovascular health.
Source: I.Wallace, E. Howden, D. Green, G. Sesa-Ashton. Exercise Capacity and Vascular Function in Long-COVID Sufferers. Heart, Lung and Circulation. ABSTRACT| VOLUME 32, SUPPLEMENT 3, S114-S115, JULY 2023. https://www.heartlungcirc.org/article/S1443-9506(23)04000-3/fulltext