Category: Exercise

Exercise capacity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) treated with long-term pyridostigmine

Abstract:

Background: The pathophysiology underlying exertional intolerance in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remains poorly understood. Previously, a single-dose of 60 mg pyridostigmine, a reversible acetylcholinesterase inhibitor, was found to acutely improve aerobic capacity (Joseph, P. et al. Chest 2022; 162:1116–26).

Aims: To build upon these prior findings, this study aimed to evaluate the long-term effect (>1 month) of pyridostigmine treatment on exercise intolerance in ME/CFS.

Methods: Between 2017-2022, patients who met the National Academy of Medicine criteria for ME/CFS, and had a minimum of two clinical, constant load, submaximal exercise tests (Shape Medical System, MN) were evaluated. Patients who began pyridostigmine after their baseline test were considered the treatment group. Measurements were taken at baseline (T0) and most recent follow-up (T1).

Results: At the follow-up evaluation (690 ± 547 days), the treatment group (n=37, dose range: 24-360mg/d) demonstrated a significant increase in oxygen uptake efficiency slope (OUES) (T0: 1.82 ± 0.56, T1: 1.98 ± 0.53; p=0.044) and pulmonary vascular capacitance (PVCAP) (T0: 486.19 ± 169.89 ml*mmHg, T1: 540.03 ± 170.59 ml*mmHg; p=0.040). These differences were not observed in the control group (n=16) OUES (T0: 1.62 ± 0.40, T1: 1.77 ± 0.47; p=0.268) and PVCAP (T0: 446.94 ± 144.80 ml*mmHg, T1: 465.81 ± 124.34 ml*mmHg; p=0.590).

Conclusion: Long-term treatment with pyridostigmine improved aerobic capacity in ME/CFS as demonstrated by an increase in OUES, mediated by improvements in central hemodynamics (PVCAP).

Source: Johanna Squires, Sarra Al-Zayer, David Systrom. Exercise capacity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) treated with long-term pyridostigmine. European Respiratory Journal Sep 2023, 62 (suppl 67) PA4639; DOI: 10.1183/13993003.congress-2023.PA4639 https://erj.ersjournals.com/content/62/suppl_67/PA4639

Maximal Oxidative Capacity During Exercise is Associated with Muscle Power Output in Patients with Long coronavirus disease 2019 (COVID-19) Syndrome. A Moderation Analysis

Abstract:

Background & Aims: Long COVID syndrome (LCS) involves persistent symptoms experienced by many patients after recovering from coronavirus disease 2019 (COVID-19). We aimed to assess skeletal muscle energy metabolism, which is closely related to peak fat oxidation rates during exercise, in patients with LCS compared with healthy controls. We also examined whether muscle power output mediates the relationship between COVID-19 and skeletal muscle energy metabolism.

Methods: In this cross-sectional study, we enrolled 71 patients with LCS and 63 healthy controls. We assessed clinical characteristics such as body composition, physical activity, and muscle strength. We used cardiopulmonary exercise testing to evaluate substrate oxidation rates during graded exercise. We performed statistical analyses to compare group characteristics and peak fat oxidation differences based on power output.

Results: The two-way analysis of covariance (ANCOVA) results, adjusted for covariates, showed that the patients with LCS had lower absolute maximal fatty acid oxidation (MFO), relative MFO/fat-free mass (FFM), absolute carbohydrates oxidation (CHox), relative CHox/FFM, and oxygen uptake (VO2) at maximum fat oxidation (mL∙min−1) than the healthy controls (P < 0.05). Moderation analysis indicated that muscle power output significantly influenced the relationship between LCS and reduced peak fat oxidation (interaction β = −0.105 [95% confidence interval −0.174; −0.036]; P = 0.026). Therefore, when muscle power output was below 388 W, the effect of the LCS on MFO was significant (62% in our study sample P = 0.010). These findings suggest compromised mitochondrial bioenergetics and muscle function, represented by lower peak fat oxidation rates, in the patients with LCS compared with the healthy controls.

Conclusion: The patients with LCS had lower peak fat oxidation during exercise compared with the healthy controls, potentially indicating impairment in skeletal muscle function. The relationship between peak fat oxidation and LCS appears to be mediated predominantly by muscle power output. Additional research should continue investigating LCS pathogenesis and the functional role of mitochondria.

Source: Robinson Ramírez-Vélez, Sergio Oscoz-Ochandorena, Yesenia García-Alonso, Nora García-Alonso, Gaizka Legarra-Gorgoñon, Julio Oteiza, Ander Ernaga Lorea, Mikel Izquierdo, María Correa-Rodríguez. Maximal Oxidative Capacity During Exercise is Associated with Muscle Power Output in Patients with Long coronavirus disease 2019 (COVID-19) Syndrome. A Moderation Analysis. Clinical Nutrition ESPEN, 2023, ISSN 2405-4577, https://doi.org/10.1016/j.clnesp.2023.10.009. https://www.sciencedirect.com/science/article/pii/S2405457723021666 (Full text)

Decreased physical performance despite objective and subjective maximal exhaustion in post-COVID-19 individuals with fatigue

Abstract:

Introduction: Fatigue is a common symptom in post-COVID-19 patients. Individuals with fatigue often perform less well compared to healthy peers or without fatigue. It is not yet clear to what extent fatigue is related to the inability to reach maximum exhaustion during physical exercise.

Methods: A symptom-based questionnaire based on the Carruthers guidelines (2003) was used for reporting the presence of fatigue and further symptoms related to COVID-19 from 85 participants (60.0% male, 33.5 ± 11.9 years). Cardiopulmonary exercise testing (CPET) and lactate measurement at the end of the test were conducted. Objective and subjective exhaustion criteria according to Wasserman of physically active individuals with fatigue (FS) were compared to those without fatigue (NFS).

Results: Differences between FS and NFS were found in Peak V̇O2/BM (p < 0.001) and Max Power/BM (p < 0.001). FS were more likely to suffer from further persistent symptoms (p < 0.05). The exhaustion criterion Max. lactate was reached significantly more often by NFS individuals.

Conclusion: Although the aerobic performance (Max Power/BM) and the metabolic rate (Peak V̇O2/BM and Max. lactate) of FS were lower compared to NFS, they were equally able to reach objective exhaustion criteria. The decreased number of FS who reached the lactate criteria and the decreased V̇O2 peak indicates a change in metabolism. Other persistent post-COVID-19 symptoms besides fatigue may also impair performance, trainability and the ability to reach objective exhaustion.

Trial registration: Trial registration: DRKS00023717; date of registration: 15.06.2021 (retrospectively registered).

Source: Vollrath S, Matits L, Schellenberg J, Kirsten J, Steinacker JM, Bizjak DA. Decreased physical performance despite objective and subjective maximal exhaustion in post-COVID-19 individuals with fatigue. Eur J Med Res. 2023 Aug 26;28(1):298. doi: 10.1186/s40001-023-01274-5. PMID: 37633931; PMCID: PMC10464445. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10464445/ (Full text)

Dysregulation of extracellular vesicle protein cargo in female ME/CFS cases and sedentary controls in response to maximal exercise

Abstract:

In healthy individuals, physical exercise improves cardiovascular health and muscle stre ngth, alleviates fatigue, and reduces risk of chronic diseases. Although exercise is suggested as a lifestyle intervention to manage various chronic illnesses, it negatively affects people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), who suffer from exercise intolerance. We hypothesized that altered extracellular vesicle (EV) signaling in ME/CFS patients after an exercise challenge may contribute to their prolonged and exacerbated negative response to exertion (post-exertional malaise).

EVs were isolated by size exclusion chromatography from the plasma of 18 female ME/CFS patients and 17 age- and BMI-matched female sedentary controls at three time points: before, 15 minutes, and 24 hours after a maximal cardiopulmonary exercise test. EVs were characterized using nanoparticle tracking analysis and their protein cargo was quantified using Tandem Mass Tag-based (TMT) proteomics.

The results show that exercise affects the EV proteome in ME/CFS patients differently than in healthy individuals and that changes in EV proteins after exercise are strongly correlated with symptom severity in ME/CFS. Differentially abundant proteins in ME/CFS patients vs. controls were involved in many pathways and systems, including coagulation processes, muscle contraction (both smooth and skeletal muscle), cytoskeletal proteins, the immune system, and brain signaling.

Source: Ludovic Giloteaux, Katherine A. Glass, Arnaud Germain, Sheng Zhang, Maureen R. Hanson. Dysregulation of extracellular vesicle protein cargo in female ME/CFS cases and sedentary controls in response to maximal exercise. bioRxiv 2023.08.28.555033; doi: https://doi.org/10.1101/2023.08.28.555033 https://www.biorxiv.org/content/10.1101/2023.08.28.555033v1.full (Full text)

Consequences of sarcolemma fatigue on maximal muscle strength production in patients with myalgic encephalomyelitis/chronic fatigue syndrome

Highlights:

  • Does force failure result from sarcolemma fatigue in Myalgic Encephalomyelitis patients?
  • Two groups of Myalgic Encephalomyelitis patients with or not M wave alterations were compared.
  • Maximal handgrip strength and M wave in forearm muscle were simultaneously measured.
  • Post-exercise changes in Maximal handgrip strength and M wave were positively correlated.
  • The post exercise sarcolemma fatigue measured could be the cause of muscle failure in these patients.

Background: Myalgic encephalomyelitis is an invalidating chronic disease often associated with exercise-induced alterations of muscle membrane excitability (M wave). No simultaneous measurements of maximal isometric force production and sarcolemma fatigue in the same muscle group have been previously reported. We hypothesized that M wave alterations could be partly responsible for the reduced muscle force present in this invalidating disease.

Methods: This retrospective study compared two groups of patients who presented (n = 30) or not (n = 28) alterations of M waves evoked by direct muscle stimulation during and after a cycling exercise bout. The maximal handgrip strength was measured before and after exercise, concomitantly with electromyogram recordings from flexor digitorum longus muscle. The patients also answered a questionnaire to identify eventual exacerbation of their clinical symptoms following the exercise test.

Findings: The M wave amplitude significantly decreased in muscles and the M wave duration significantly increased in the group of patients with M wave alterations after exercise. Resting values of handgrip were significantly lower in patients with exercise-induced M-wave alterations than in patients without M-wave abnormalities. In patients with exercise-induced M-wave alterations, handgrip significantly decreased after exercise and the changes in handgrip and M wave were positively correlated. The frequency of post-exertion malaise, increased fatigue, myalgia, headache and cognitive dysfunction was significantly higher in patients with M-wave alterations and variations in handgrip after exercise.

Interpretation: These data suggest that post-exercise sarcolemma fatigue often measured in patients with myalgic encephalomyelitis could be the cause of muscle failure.

Source: Frédérique Retornaz, Chloé Stavris, Yves Jammes. Consequences of sarcolemma fatigue on maximal muscle strength production in patients with myalgic encephalomyelitis/chronic fatigue syndrome. Clinical Biomechanics, Volume 108, August 2023, 106055. https://www.sciencedirect.com/science/article/pii/S0268003323001869 (Full text)

Exercise Capacity and Vascular Function in Long-COVID Sufferers

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 

Sex-Dependent Transcriptional Changes in Response to Stress in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Project

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, multi-symptom illness characterized by debilitating fatigue and post-exertional malaise (PEM). Numerous studies have reported sex differences at the epidemiological, cellular, and molecular levels between male and female ME/CFS patients. To gain further insight into these sex-dependent changes, we evaluated differential gene expression by RNA-sequencing (RNA-Seq) in 33 ME/CFS patients (20 female, 13 male) and 34 matched healthy controls (20 female and 14 male) before, during, and after an exercise challenge intended to provoke PEM.
Our findings revealed that pathways related to immune-cell signaling (including IL-12) and natural killer cell cytotoxicity were activated as a result of exertion in the male ME/CFS cohort, while female ME/CFS patients did not show significant enough changes in gene expression to meet the criteria for the differential expression. Functional analysis during recovery from an exercise challenge showed that male ME/CFS patients had distinct changes in the regulation of specific cytokine signals (including IL-1β). Meanwhile, female ME/CFS patients had significant alterations in gene networks related to cell stress, response to herpes viruses, and NF-κβ signaling. The functional pathways and differentially expressed genes highlighted in this pilot project provide insight into the sex-specific pathophysiology of ME/CFS.
Source: Gamer J, Van Booven DJ, Zarnowski O, Arango S, Elias M, Kurian A, Joseph A, Perez M, Collado F, Klimas N, et al. Sex-Dependent Transcriptional Changes in Response to Stress in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Project. International Journal of Molecular Sciences. 2023; 24(12):10255. https://doi.org/10.3390/ijms241210255 https://www.mdpi.com/1422-0067/24/12/10255 (Full text)

Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID

Abstract:

Background: Mechanisms underlying persistent cardiopulmonary symptoms following SARS-CoV-2 infection (post-acute sequelae of COVID-19 “PASC” or “Long COVID”) remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity.

Methods: We conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults > 1 year after confirmed SARS-CoV-2 infection in a post-COVID cohort, compared those with or without symptoms, and correlated findings with previously measured biomarkers.

Results: Sixty participants (median age 53, 42% female, 87% non-hospitalized) were studied at median 17.6 months following SARS-CoV-2 infection. On CPET, 18/37 (49%) with symptoms had reduced exercise capacity (<85% predicted) compared to 3/19 (16%) without symptoms (p = 0.02). Adjusted peak VO2 was 5.2 ml/kg/min lower (95%CI 2.1-8.3; p = 0.001) or 16.9% lower percent predicted (95%CI 4.3-29.6; p = 0.02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2 more than 1 year later. Late-gadolinium enhancement on CMR and arrhythmias were absent.

Conclusions: Cardiopulmonary symptoms >1 year following COVID-19 were associated with reduced exercise capacity, which was associated with elevated inflammatory markers early in PASC. Chronotropic incompetence may explain exercise intolerance among some with cardiopulmonary Long COVID.

Source: Durstenfeld MS, Peluso MJ, Kaveti P, Hill C, Li D, Sander E, Swaminathan S, Arechiga VM, Lu S, Goldberg SA, Hoh R, Chenna A, Yee BC, Winslow JW, Petropoulos CJ, Kelly JD, Glidden DV, Henrich TJ, Martin JN, Lee YJ, Aras MA, Long CS, Grandis DJ, Deeks SG, Hsue PY. Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID. J Infect Dis. 2023 May 11:jiad131. doi: 10.1093/infdis/jiad131. Epub ahead of print. PMID: 37166076. https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiad131/7159960 (Full text available as PDF file)

Post-acute Sequelae of SARS Co-V2 and Chronic Fatigue/Myalgic Encephalitis Share Similar Pathophysiologic Mechanisms of Exercise Limitation

Abstract:

Abstract available online: https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A6470

Source: S. Jothi, G. Claessen, M. Insel, S. Kubba, E. Howden, S.-R. Carmona, F.P. Rischard. Post-acute Sequelae of SARS Co-V2 and Chronic Fatigue/Myalgic Encephalitis Share Similar Pathophysiologic Mechanisms of Exercise Limitation. https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A6470

ME/CFS Pathophysiology Investigated by Invasive Cardiopulmonary Exercise Testing and Autonomic Function Testing

Abstract

Introduction: Mechanisms underlying exercise and orthostatic intolerance in myalgic encephalomyelitis/chronic
fatigue syndrome (ME/CFS) have been uncovered by invasive cardiopulmonary exercise testing (iCPET) and
autonomic function testing (AFT), but the relationships between the two are not known. This study aims to determine
if there is overlap of cardiovascular and respiratory pathophysiology in patients who have undergone both
tests.

Methods: Between January 2017 and April 2022, 62 patients were identified with a contemporary iCPET and
AFT. Key variables from the iCPET included peak oxygen uptake (pVO2), cardiac output (pQc), right atrial pressure
(pRAP), and systemic oxygen extraction (Ca-vOy/Hgb) at peak exercise. Key variables from the autonomic testing
included epidermal and sweat gland small fiber neurite density, electrochemical skin conductance, and change in
heart rate (AH) and end tidal carbon dioxide (AETCO2) from supine to upright during the tilt table test
(TTT).

Results: All 62 patients demonstrated preload failure (pRAP < 6.5mmHg). Of this group, 54 patients (87.1%) fulfilled NAM criteria for ME/CFS, with 32 testing positive (59.3%) for small fiber neuropathy (SFN) using either morphological and/or functional testing. Significant correlations were found between pVOg and both AH (r=-0.439. P<0.05) and AETCO, (r=0.474, P<0.05) during TTT. The same tilt table variables were found to be significantly correlated with pQc (r=-0.365, P<0.05 and r=0.351, P<0.05) from the iCPET. It should be noted that 8 of the ME/CFS SFN patients (25%) fulfilled diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) based on the tilt table test.

Conclusion: Decreased oxygen uptake and cardiac output at peak exercise during iCPET correlated with a greater change in heart rate and ETCO from supine to upright during TTT. There appears to be significant overlap of cardiopulmonary pathophysiology in ME/CFS underlying exercise and orthostatic symptoms.

Source: J. Squires, K. Wichmann Madsen, M.C. Stovall, S. Al-Zayer, W. Xiao, C.-J. Chang, P. Novak, D.M. Systrom. ME/CFS Pathophysiology Investigated by Invasive Cardiopulmonary Exercise Testing and Autonomic Function Testing. American Journal of Respiratory and Critical Care Medicine 2023;207:A2996. https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A2996