How does cervical spinal cord injury impact the cardiopulmonary response to exercise?

https://doi.org/10.1016/j.resp.2021.103714Get rights and content

Highlights

  • Cervical spinal cord injury (C-SCI) has severe cardiac and respiratory consequences.

  • We examined how these consequences alter cardiopulmonary responses to arm exercise.

  • C-SCI causes altered ventilatory patterns during sub-maximal arm exercise.

  • Along with impaired cardio-acceletory function, these alterations may reduce aerobic capacity.

Abstract

We compared cardiopulmonary responses to arm-ergometry in individuals with cervical spinal cord injury (C-SCI) and able-bodied controls. We hypothesized that individuals with C-SCI would have higher respiratory frequency (fb) but lower tidal volume (VT) at a given work rate and dynamically hyperinflate during exercise, whereas able-bodied individuals would not. Participants completed pulmonary function testing, an arm-ergometry test to exhaustion, and a sub-maximal exercise test consisting of four-minute stages at 20, 40, 60, and 80% peak work rate. Able-bodied individuals completed a further sub-maximal test with absolute work rate matched to C-SCI. During work rate matched sub-maximal exercise, C-SCI had smaller VT (main effect p < 0.001) compensated by an increased fb (main effect p = 0.009). C-SCI had increased end-expiratory lung volume at 80% peak work rate vs. rest (p < 0.003), whereas able-bodied did not. In conclusion, during arm-ergometry, individuals with C-SCI exhibit altered ventilatory patterns characterized by reduced VT, higher fb, and dynamic hyperinflation that may contribute to the observed reduced aerobic exercise capacity.

Section snippets

INTRODUCTION

Respiratory and cardiovascular responses to exercise are often reported to be significantly impaired following cervical spinal cord injury (C-SCI) compared to those observed in able-bodied individuals (Hostettler et al., 2012; West et al., 2016). For example, while peak minute ventilation (V̇E) in able-bodied athletes may approach or even exceed 150 L.min-1 during lower-limb exercise, athletes with C-SCI have a V̇Epeak of approximately 50 L.min-1 during upper-limb exercise (Gee et al., 2019;

Participants

10 highly trained individuals with C-SCI (9 M/1 F, 36 ± 6 years) and 10 recreationally active able-bodied controls matched for age, sex, and height (9 M/1 F, 32 ± 4 years) completed the study (Table 1). C-SCI participants trained for and competed in wheelchair rugby, wheelchair tennis, and/or wheelchair athletics, with six of the individuals with C-SCI having competed at the international level and the remaining four at the national level. Able-bodied controls were recruited from the local

Resting Pulmonary Function

Resting pulmonary function is reported in Table 2. Compared to able-bodied controls, highly trained individuals with C-SCI had a smaller TLC (p = 0.049), inspiratory capacity (p = 0.001), and inspiratory reserve volume (p = 0.004), but a larger residual volume (p = 0.005). peak expiratory flow, FVC, and FEV1 (all p < 0.004) were reduced following C-SCI whereas FEV1/FVC was larger (p = 0.006) (see Table 2).

Maximal Exercise Test

Peak values recorded during the maximal exercise test are reported in Table 3. C-SCI

DISCUSSION

This study examined the effects of C-SCI on the cardiopulmonary responses to exercise during both maximal and sub-maximal arm-ergometry compared to able bodied individuals. The major novel finding was that individuals with C-SCI exhibit altered ventilatory patterns during exercise and dynamic hyperinflation, a finding that does not appear to be due to the arm-ergometry modality of exercise but rather to the C-SCI itself. Dynamic hyperinflation may have implications for exercise performance via

Author contributions

The experiments were performed at the International Collaboration on Repair Discoveries. CMG and CRW conceived the study. All authors designed the study. CMG performed data collection and analysis. CMG and CRW interpreted results and drafted the work. All authors revised the work critically for important intellectual content, approved the final version of the manuscript and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any

Funding

This work was supported by Mitacs through the Mitacs Accelerate program.

Declaration of Competing Interest

The authors report no declarations of interest.

Acknowledgements

The authors would like to thank all participants who took part in this study.

References (40)

  • J.A.L. Calbet

    Why do arms extract less oxygen than legs during exercise?

    AJP Regul. Integr. Comp. Physiol.

    (2005)
  • J.A.L. Calbet et al.

    Cardiac output and leg and arm blood flow during incremental exercise to exhaustion on the cycle ergometer

    J. Appl. Physiol.

    (2007)
  • P.M.A. Calverley et al.

    Flow limitation and dynamic hyperinflation: Key concepts in modern respiratory physiology

    Eur. Respir. J.

    (2005)
  • B. Celli et al.

    Ventilatory muscle recruitment during unsupported arm exercise in normal subjects

    J. Appl. Physiol.

    (1988)
  • W. Cheyne et al.

    Late Breaking Abstract - The effect of negative intrathoracic pressure and dynamic hyperinflation on heart-lung interaction during exercise

    (2019)
  • S. Eerden et al.

    Maximal and submaximal aerobic tests for wheelchair-dependent persons with spinal cord injury: a systematic review to summarize and identify useful applications for clinical rehabilitation

    Disabil. Rehabil.

    (2018)
  • C.M. Gee et al.

    Spinal Cord Injury Impairs Cardiovascular Capacity in Elite Wheelchair Rugby Athletes

    Clin. J. Sport Med.

    (2020)
  • C.M. Gee et al.

    Respiratory muscle training in athletes with cervical spinal cord injury: effects on cardiopulmonary function and exercise capacity

    J. Physiol.

    (2019)
  • K.E. Griggs et al.

    Thermoregulation during intermittent exercise in athletes with a spinal-cord injury

    Int. J. Sports Physiol. Perform.

    (2015)
  • K.G. Henke et al.

    Regulation of end-expiratory lung volume during exercise

    J. Appl. Physiol.

    (1988)
  • View full text