Cardiorespiratory Fitness and Neuromuscular Performance in Patients Recovered from COVID-19

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Abstract

Objective

COVID-19 affects cardiorespiratory and muscular systems, causing dysfunctions that may persist after recovery from the acute infection and treatment. The aim of this study was to evaluate cardiorespiratory fitness and neuromuscular performance in these patients.

Methods

Patients recovered from mild (n=31) and severe (n=17) COVID-19 were evaluated and compared to healthy subjects (n=15). All volunteers underwent a maximal cardiopulmonary exercise test with simultaneous acquisition of electromyography (EMG). Power output, oxygen uptake (VO 2 ), pulse oxygen (O 2 Pulse), cardiovascular efficiency (ΔHR/ΔVO 2 ), ventilation (VE), breathing reserve (BR) and ventilatory efficiency (VE/VCO 2 slope) were analyzed. From EMG, power output for type Ia and IIa activation as well as total neuromuscular efficiency (Δwatts/Δ%RMS) were determined.

Results

Patients with severe COVID-19 presented lower VO 2 , O 2 Pulse and VE than mild COVID-19 patients and healthy subjects (p < 0.05 for all comparisons). No differences in ΔHR/ΔVO 2 , BR or VE/VCO 2 slope were observed among the groups (p > 0.05 for all comparisons). Type IIa and IIb fibers were activated at lower power output in severe than in mild COVID-19 patients and healthy subjects (p < 0.05). Δwatts/Δ%RMS was lower in severe than in mild COVID-19 patients and healthy subjects (p < 0.05).

Conclusion

Patients recovered from severe COVID-19 present low cardiorespiratory fitness, activate glycolytic fibers at low power outputs, and show low neuromuscular efficiency; while patients recovered from mild COVID-19 do not present these sequels.

Article activity feed

  1. SciScore for 10.1101/2021.01.11.20248930: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIRB: This study was approved by the local research ethics committee (Instituto de Educação Superior da Paraíba - IESP, opinion No.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    GraphPad Prism 7.0 and GPower 3.1.9.7 software were used.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    A significant reduction in O2pulse was also observed in the group of individuals with severe manifestations; however, the normal ascending behavior of the O2pulse curve and preserved ventilatory efficiency reduced the probability of central cardiovascular limitation. One possibility is that those deregulatory mechanisms do not persist after a time of recovery. Another possibility is that only critical patients present significant pulmonary perfusion deregulation. Thus, individuals recovered from COVID-19 who had severe manifestations had lower functional capacity, without evidence of significant central cardiorespiratory changes, than those recovered from mild COVID-19 or healthy subjects. The reduction in neuromuscular efficiency demonstrated through electromyography suggests that the effort limitation of these individuals is related to a peripheral mechanism. Severe COVID-19 patients presented lower neuromuscular efficiency, probably due to myositis and a higher inflammatory pattern. Myositis is characterized by the presence of prominent muscle membrane irritability. In myositis, there is invasion and destruction of muscle fibers by cytotoxic T cells(24). SARS-CoV-2 activates inflammatory cytokines, causing inflammatory injury in muscle cells(25). The degree of abnormal muscle membrane irritability is related to disease severity. Mao et al.(26) showed that 11% of the patients had evidence of skeletal muscle injury (creatinine kinase>200 U/L and skeletal muscle pain). Injury...

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.