Long COVID was associated with a 4.9 ml/kg/min lower peak VO2 compared to recovered individuals without symptoms, indicating significantly reduced exercise capacity.
Meta-Analysis (n=2,209)
Does SARS-CoV-2 infection and Long COVID reduce peak VO2 exercise capacity in adults?
Cardiopulmonary exercise testing demonstrates that exercise capacity (peak VO2) is significantly reduced 3-18 months after SARS-CoV-2 infection, particularly among those with Long COVID, driven by deconditioning and other multifactorial mechanisms.
Effect estimate: Mean difference -4.9 ml/kg/min (95% CI -6.4 to -3.4)
Abstract Importance Reduced exercise capacity is commonly reported among individuals with Long COVID (LC). Cardiopulmonary exercise testing (CPET) is the gold-standard to measure exercise capacity to identify causes of exertional intolerance. Objectives To estimate the effect of SARS-CoV-2 infection on exercise capacity including those with and without LC symptoms and to characterize physiologic patterns of limitations to elucidate possible mechanisms of LC. Data Sources We searched PubMed, EMBASE, and Web of Science, preprint severs, conference abstracts, and cited references in December 2021 and again in May 2022. Study Selection We included studies of adults with SARS-CoV-2 infection at least three months prior that included CPET measured peak VO 2 . 3,523 studies were screened independently by two blinded reviewers; 72 (2.2%) were selected for full-text review and 36 (1.2%) met the inclusion criteria; we identified 3 additional studies from preprint servers. Data Extraction and Synthesis Data extraction was done by two independent reviewers according to PRISMA guidelines. Data were pooled with random-effects models. Main Outcomes and Measures A priori primary outcomes were differences in peak VO 2 (in ml/kg/min) among those with and without SARS-CoV-2 infection and LC. Results We identified 39 studies that performed CPET on 2,209 individuals 3-18 months after SARS-CoV-2 infection, including 944 individuals with LC symptoms and 246 SARS-CoV-2 uninfected controls. Most were case-series of individuals with LC or post-hospitalization cohorts. By meta-analysis of 9 studies including 404 infected individuals, peak VO 2 was 7.4 ml/kg/min (95%CI 3.7 to 11.0) lower among infected versus uninfected individuals. A high degree of heterogeneity was attributable to patient and control selection, and these studies mostly included previously hospitalized, persistently symptomatic individuals. Based on meta-analysis of 9 studies with 464 individuals with LC, peak VO 2 was 4.9 ml/kg/min (95%CI 3.4 to 6.4) lower compared to those without symptoms. Deconditioning was common, but dysfunctional breathing, chronotropic incompetence, and abnormal oxygen extraction were also described. Conclusions and Relevance These studies suggest that exercise capacity is reduced after SARS-CoV-2 infection especially among those hospitalized for acute COVID-19 and individuals with LC. Mechanisms for exertional intolerance besides deconditioning may be multifactorial or related to underlying autonomic dysfunction.
Durstenfeld et al. (Thu,) conducted a meta-analysis in Post-acute sequelae of COVID-19 (Long COVID) (n=2,209). Long COVID (symptomatic after SARS-CoV-2 infection) vs. Recovered individuals without Long COVID symptoms was evaluated on Difference in peak VO2 (ml/kg/min) (Mean difference -4.9 ml/kg/min, 95% CI -6.4 to -3.4). Long COVID was associated with a 4.9 ml/kg/min lower peak VO2 compared to recovered individuals without symptoms, indicating significantly reduced exercise capacity.