Category: Exercise

Symptom burden correlates to impairment of diffusion capacity and exercise intolerance in long COVID patients

Abstract:

After acute infection with the SARS-CoV-2 virus, a considerable number of patients remains symptomatic with pathological changes in various organ systems. This study aimed to relate the physical and mental burden of symptoms of long COVID patients to the findings of a somatic evaluation.

In patients with persistent long COVID symptoms three months after acute infection we assessed physical and mental health status using the SF-36 questionnaire. The cohort was dichotomised by the results (upper two quartiles vs. lower to quartiles) and compared with regard to transthoracic echocardiography, body plethysmography (including diffusion capacity), capillary blood gas analysis and 6-min walk test (6-MWT). From February 22 to September 13, 2021, 463 patients were prospectively examined, of which 367 completed the SF-36 questionnaire. A positive correlation between initial disease severity (need for hospitalization, intensive care medicine) and resulting symptom burden at follow-up could be demonstrated.

Patients with impaired subjective physical and mental status were significantly more likely to be women. There was a significant correlation between symptom severity and reduced exercise tolerance in the 6-MWT (495.6 ± 83.7 m vs 549.7 ± 71.6 m, p < 0.001) and diffusion capacity for carbon monoxide (85.6 ± 14.3% of target vs 94.5 ± 14.4, p < 0.001). In long COVID patients, initial disease severity is correlated with symptom burden after at least 3 months of follow-up. Highly symptomatic long COVID patients show impaired diffusion capacity and 6-MWT despite average or mildly affected mechanical lung parameters. It must be further differentiated whether this corresponds to a transient functional impairment or whether it is a matter of defined organ damage.

Source: Kersten, J., Wolf, A., Hoyo, L. et al. Symptom burden correlates to impairment of diffusion capacity and exercise intolerance in long COVID patients. Sci Rep 12, 8801 (2022). https://doi.org/10.1038/s41598-022-12839-5  https://www.nature.com/articles/s41598-022-12839-5 (Full text)

Respiratory muscle dysfunction in long-COVID patients

Abstract:

Purpose: Symptoms often persistent for more than 4 weeks after COVID-19-now commonly referred to as ‘Long COVID’. Independent of initial disease severity or pathological pulmonary functions tests, fatigue, exertional intolerance and dyspnea are among the most common COVID-19 sequelae. We hypothesized that respiratory muscle dysfunction might be prevalent in persistently symptomatic patients after COVID-19 with self-reported exercise intolerance.

Methods: In a small cross-sectional pilot study (n = 67) of mild-to-moderate (nonhospitalized) and moderate-to-critical convalescent (formerly hospitalized) patients presenting to our outpatient clinic approx. 5 months after acute infection, we measured neuroventilatory activity P0.1, inspiratory muscle strength (PImax) and total respiratory muscle strain (P0.1/PImax) in addition to standard pulmonary functions tests, capillary blood gas analysis, 6 min walking tests and functional questionnaires.

Results: Pathological P0.1/PImax was found in 88% of symptomatic patients. Mean PImax was reduced in hospitalized patients, but reduced PImax was also found in 65% of nonhospitalized patients. Mean P0.1 was pathologically increased in both groups. Increased P0.1 was associated with exercise-induced deoxygenation, impaired exercise tolerance, decreased activity and productivity and worse Post-COVID-19 functional status scale. Pathological changes in P0.1, PImax or P0.1/PImax were not associated with pre-existing conditions.

Conclusions: Our findings point towards respiratory muscle dysfunction as a novel aspect of COVID-19 sequelae. Thus, we strongly advocate for systematic respiratory muscle testing during the diagnostic workup of persistently symptomatic, convalescent COVID-19 patients.

Source: Hennigs JK, Huwe M, Hennigs A, Oqueka T, Simon M, Harbaum L, Körbelin J, Schmiedel S, Schulze Zur Wiesch J, Addo MM, Kluge S, Klose H. Respiratory muscle dysfunction in long-COVID patients. Infection. 2022 May 16:1–7. doi: 10.1007/s15010-022-01840-9. Epub ahead of print. PMID: 35570238; PMCID: PMC9108020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9108020/ (Full text)

Impaired exercise capacity in post-COVID syndrome: the role of VWF-ADAMTS13 axis

Abstract:

Post-COVID syndrome (PCS) or Long-COVID is an increasingly recognised complication of acute SARS-CoV-2 infection, characterised by persistent fatigue, reduced exercise tolerance chest pain, shortness of breath and cognitive slowing. Acute COVID-19 is strongly linked with increased risk of thrombosis; a prothrombotic state, quantified by elevated Von Willebrand Factor (VWF) Antigen (Ag):ADAMTS13 ratio, and is associated with severity of acute COVID-19 infection. We investigated if patients with PCS also had evidence of a pro-thrombotic state associating with symptom severity.

In a large cohort of patients referred to a dedicated post-COVID-19 clinic, thrombotic risk including VWF(Ag):ADAMTS13 ratio, was investigated. An elevated VWF(Ag):ADAMTS13 ratio (≥1.5) was raised in nearly one-third of the cohort and four times more likely in patients with impaired exercise capacity as evidenced by desaturation ≥3% and/or rise in lactate level more than 1 from baseline on 1-minute sit to stand test and/or 6-minute walk test (p<0.0001). 20% (56/276) had impaired exercise capacity, of which 55% (31/56) had a raised VWF(Ag):ADAMTS13 ratio ≥1.5 (p<0.0001). FVIII and VWF(Ag) were elevated in 26% and 18% respectively and support a hypercoagulable state in some patients with PCS.

These findings suggest possible ongoing microvascular/endothelial dysfunction in the pathogenesis of PCS and highlight a potential role for antithrombotic therapy in the management of these patients.

Source: Prasannan N, Heightman M, Hillman T, Wall E, Bell R, Kessler A, Neave L, Doyle AJ, Devaraj A, Singh D, Dehbi HM, Scully M. Impaired exercise capacity in post-COVID syndrome: the role of VWF-ADAMTS13 axis. Blood Adv. 2022 May 11:bloodadvances.2021006944. doi: 10.1182/bloodadvances.2021006944. Epub ahead of print. PMID: 35543533; PMCID: PMC9098525. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9098525/ (Full text)

The Updated NICE Guidance Exposed the Serious Flaws in CBT and Graded Exercise Therapy Trials for ME/CFS

Abstract:

The British National Institute for Health and Care Excellence (NICE) recently published its updated guidelines for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). NICE concluded, after an extensive review of the literature, that graded exercise therapy (GET) is harmful and should not be used, and that cognitive behavioural therapy (CBT) is only an adjunctive and not a curative treatment. Leading proponents of the cognitive behavioural model (CBmodel) find it difficult to accept this paradigm shift.
In, for example, an article in The Lancet, they try to argue that the new NICE guideline is based on ideology instead of science. In this article we reviewed the evidence they used to support their claims. Our analysis shows that the trials they used in support suffered from serious flaws which included badly designed control groups, relying on subjective primary outcomes in non-blinded studies, including patients in their trials who didn’t have the disease under investigation or had a self-limiting disease, selective reporting, outcome switching and making extensive endpoint changes, which created an overlap in entry and recovery criteria, using a post-hoc definition of recovery which included the severely ill, not publishing results that contradict their own conclusion, ignoring their own (objective) null effect, etc.
The flaws in these trials all created a bias in favour of the interventions. Despite all these flaws, treatments that are said to lead to recovery in reality do not lead to objective improvement. Therefore, these studies do not support the claim that CBT and GET are effective treatments. Moreover, the arguments that are used to claim that NICE was wrong, in reality, highlight the absence of evidence for the safety and efficacy of CBT and GET and strengthen the decision by NICE to drop CBT and GET as curative treatments for ME/CFS.
Source: Vink M, Vink-Niese A. The Updated NICE Guidance Exposed the Serious Flaws in CBT and Graded Exercise Therapy Trials for ME/CFS. Healthcare. 2022; 10(5):898. https://doi.org/10.3390/healthcare10050898 https://www.mdpi.com/2227-9032/10/5/898/htm (Full text)

Neurovascular Dysregulation and Acute Exercise Intolerance in ME/CFS: A Randomized, Placebo-Controlled Trial of Pyridostigmine

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by intractable fatigue, post-exertional malaise, and orthostatic intolerance, but its pathophysiology is poorly understood. Pharmacologic cholinergic stimulation was used to test the hypothesis that neurovascular dysregulation underlies exercise intolerance in ME/CFS.

Research Question: Does neurovascular dysregulation contribute to exercise intolerance in ME/CFS and can its treatment improve exercise capacity?

Methods: Forty-five subjects with ME/CFS were enrolled in a single-center, randomized, double-blind, placebo-controlled trial. Subjects were assigned in a 1:1 ratio to receive a 60 mg dose of oral pyridostigmine or placebo after an invasive cardiopulmonary exercise test (iCPET). A second iCPET was performed 50 minutes later. The primary end point was the difference in peak exercise oxygen uptake (VO2). Secondary end points included exercise pulmonary and systemic hemodynamics and gas exchange.

Results: Twenty-three subjects were assigned to pyridostigmine and 22 to placebo. The peak VO2 increased after pyridostigmine but decreased after placebo (13.3 ± 13.4 mL/min vs. -40.2 ± 21.3 mL/min, P<0.05). The treatment effect of pyridostigmine was 53.6 mL/min (95% CI, -105.2 to -2.0). Peak versus rest VO2 (25.9 ± 15.3 mL/min vs. -60.8 ± 25.6 mL/min, P<0.01), cardiac output (-0.2 ± 0.6 L/min vs. -1.9 ± 0.6 L/min, P<0.05), and RAP (1.0 ± 0.5 mm Hg vs. -0.6 ± 0.5 mm Hg, P<0.05) were greater in the pyridostigmine group compared to placebo.

Interpretation: Pyridostigmine improves peak VO2 in ME/CFS by increasing cardiac output and right ventricular filling pressures. Worsening peak exercise VO2, Qc, and RAP after placebo may signal the onset of post-exertional malaise. We suggest treatable neurovascular dysregulation underlies acute exercise intolerance in ME/CFS.

Abbreviations List: Ca-vO2 (arterial-venous oxygen content difference), iCPET (Invasive cardiopulmonary exercise test), MAP (Mean arterial pressure), mPAP (Mean pulmonary artery pressure), ME/CFS (Myalgic encephalomyelitis/chronic fatigue syndrome), PASC (Post-acute sequelae of SARS-CoV-2 infection), PAWP (Pulmonary arterial wedge pressure), POTS (Postural orthostatic tachycardia syndrome), Qc (Cardiac output), RAP (Right atrial pressure), SE (Standard error), SFN (Small fiber neuropathy), VE/VCO2 (Ventilatory efficiency), VO2 (Oxygen uptake)

Source: Phillip Joseph, MD, Rosa Pari, MD, Sarah Miller, BS, Arabella Warren, BS, Mary Catherine Stovall, BS, Johanna Squires, MSc, Chia-Jung Chang, PhD, Wenzhong Xiao, PhD, Aaron B. Waxman, MD, PhD, David M. Systrom, MD. Neurovascular Dysregulation and Acute Exercise Intolerance in ME/CFS: A Randomized, Placebo-Controlled Trial of Pyridostigmine. Chest, Published: May 05, 2022. DOI: https://doi.org/10.1016/j.chest.2022.04.146

Acute effect of pyridostigmine in exertional intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A randomized placebo-controlled clinical trial

Rationale: One third of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have evidence of small fiber neuropathy (SFN). Neurovascular dysregulation during upright exercise may be associated with impaired venoconstriction resulting in low biventricular filling pressures and impaired arteriolar constriction resulting in a mismatch between perfusion and skeletal muscle metabolism. We hypothesize that pyridostigmine, a reversible acetylcholinesterase inhibitor, may improve vascular regulation and exercise tolerance in ME/CFS by increasing sympathetic outflow.

Methods: 45 subjects (39 women, 6 men) with ME/CFS were assessed. A baseline invasive cardiopulmonary exercise test (iCPET) was performed to confirm presence of low peak exercise RAP (<6.5mmHg). Eligible subjects were blindly administered placebo (n=22) or 60mg pyridostigmine (n=23) at a 1:1 ratio. A second iCPET was performed following a 50 minute combined rest and dosing period. Serial iCPET results were compared to assess changes in oxygen uptake at peak exercise (VO2 max). Secondary outcomes included subject ventilatory efficiency (VE/VCO2), peak hemodynamic response (RAP, PCWP, SV, Qt), systemic gas exchange (Ca-vO2/Hgb), and subjective reporting of dyspnea and fatigue. Results: 39 subjects (all women) were considered in data analysis. There was a significant increase in VO2 max between iCPET 1 and iCPET 2 in the treatment group when compared with the placebo group (p = 0.043).

There was a significant decrease in the placebo group and a significant increase in the treatment group in VO2 (p = 0.008), Qt (p = 0.039), and RAP (p = 0.045) when comparing iCPET 1 peak – rest and iCPET 2 peak – rest between groups. There were no significant differences in peak arteriovenous oxygen content difference (Ca-vO2/Hgb). 38% of subjects had objective evidence of SFN with no statistically significant difference between groups.

Conclusion: Using pyridostigmine as an investigative tool, this study suggests that neurovascular dysregulation underlies acute exercise intolerance in ME/CFS. Additionally, we have new evidence that worsening vascular dysregulation results from prior exercise, which sheds insight into the post exertional malaise that is a hallmark of this syndrome.

Source: M. Stovall, P. Joseph, R. Pari, A. Warren, S. Miller, J. Squires, W. Xiao, A.B. Waxman, D.M. Systrom. Acute effect of pyridostigmine in exertional intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A randomized placebo-controlled clinical trial. American Journal of Respiratory and Clinical Care Medicine, Vol 205, p A2063, May 2022. https://www.atsjournals.org/doi/pdf/10.1164/ajrccm-conference.2022.205.1_MeetingAbstracts.A2063

The Relationship between Physical Activity and Long COVID: A Cross-Sectional Study

Abstract:

The relationship between Long Covid (LC) symptoms and physical activity (PA) levels are unclear. In this cross-sectional study, we examined this association, and the advice that individuals with LC received on PA. Adults with LC were recruited via social media. The New Zealand physical activity questionnaire short form (NZPAQ-SF) was adapted to capture current and pre-COVID-19 PA levels and activities of daily living (ADLs).
Participants reported how PA affected their symptoms, and what PA recommendations they had received from healthcare professionals and other resources; 477 participants completed the survey. Mean age (SD) was 45.69 (10.02) years, 89.1% female, 92.7% white, and median LC duration was 383.5 days (IQR: 168.25,427). Participants were less active than pre-COVID-19 (26.88 ± 74.85 vs. 361.68 ± 396.29 min per week, p < 0.001) and required more assistance with ADLs in a 7-day period compared to pre-COVID-19 (2.23 ± 2.83 vs. 0.11 ± 0.74 days requiring assistance, p < 0.001). No differences were found between the number of days of assistance required with ADLs, or the amount of PA, and the different durations of LC illness (p > 0.05).
Participants reported the effect of PA on LC symptoms as: worsened (74.84%), improved (0.84%), mixed effect (20.96%), or no effect (28.72%). Participants received contradictory advice on whether to be physically active in LC. LC is associated with a reduction in PA and a loss of independence, with most participants reporting PA worsened LC symptoms. PA level reduction is independent of duration of LC. Research is needed to understand how to safely return to PA without worsening LC symptoms.
Source: Wright J, Astill SL, Sivan M. The Relationship between Physical Activity and Long COVID: A Cross-Sectional Study. International Journal of Environmental Research and Public Health. 2022; 19(9):5093. https://doi.org/10.3390/ijerph19095093  https://www.mdpi.com/1660-4601/19/9/5093/htm (Full text)

Plasma metabolomics reveals disrupted response and recovery following maximal exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Post-exertional malaise (PEM) is a hallmark symptom of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We monitored the evolution of 1,157 plasma metabolites in 60 ME/CFS cases (45 females, 15 males) and in 45 matched healthy control subjects (30 females, 15 males) before and after two maximal Cardiopulmonary Exercise Test (CPET) challenges separated by 24 hours, with the intent of provoking PEM in patients. Four timepoints allowed exploration of the metabolic response to maximal energy-producing capacity and the recovery pattern of ME/CFS cases compared to the healthy control group.

Baseline comparison identified several significantly different metabolites, along with an enriched percentage of yet-to-be identified compounds. Additionally, temporal measures demonstrated an increased metabolic disparity between cohorts, including unknown metabolites. The effects of exertion in the ME/CFS cohort predominantly highlighted lipid- as well as energy-related pathways and chemical structure clusters, which were disparately affected by the first and second exercise sessions.

The 24-hour recovery period was distinct in the ME/CFS cohort, with over a quarter of the identified pathways statistically different. The pathways that are uniquely different 24 hours after an exercise challenge provide clues to metabolic disruptions that lead to PEM. Numerous altered pathways were observed to depend on glutamate metabolism, a crucial component to the homeostasis of many organs in the body, including the brain.

Source: Germain A, Giloteaux L, Moore GE, Levine SM, Chia JK, Keller BA, Stevens J, Franconi CJ, Mao X, Shungu DC, Grimson A, Hanson MR. Plasma metabolomics reveals disrupted response and recovery following maximal exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. JCI Insight. 2022 Mar 31:e157621. doi: 10.1172/jci.insight.157621. Epub ahead of print. PMID: 35358096. https://pubmed.ncbi.nlm.nih.gov/35358096/

Cardiopulmonary, metabolic, and perceptual responses during exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Multi-site Clinical Assessment of ME/CFS (MCAM) sub-study

Abstract:

Background: Cardiopulmonary exercise testing has demonstrated clinical utility in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). However, to what extent exercise responses are independent of, or confounded by, aerobic fitness remains unclear.

Purpose: To characterize and compare exercise responses in ME/CFS and controls with and without matching for aerobic fitness.

Methods: As part of the Multi-site Clinical Assessment of ME/CFS (MCAM) study, 403 participants (n = 214 ME/CFS; n = 189 controls), across six ME/CFS clinics, completed ramped cycle ergometry to volitional exhaustion. Metabolic, heart rate (HR), and ratings of perceived exertion (RPE) were measured. Ventilatory equivalent ([Formula: see text], [Formula: see text]), metrics of ventilatory efficiency, and chronotropic incompetence (CI) were calculated. Exercise variables were compared using Hedges’ g effect size with 95% confidence intervals. Differences in cardiopulmonary and perceptual features during exercise were analyzed using linear mixed effects models with repeated measures for relative exercise intensity (20-100% peak [Formula: see text]). Subgroup analyses were conducted for 198 participants (99 ME/CFS; 99 controls) matched for age (±5 years) and peak [Formula: see text] (~1 ml/kg/min-1).

Results: Ninety percent of tests (n = 194 ME/CFS, n = 169 controls) met standard criteria for peak effort. ME/CFS responses during exercise (20-100% peak [Formula: see text]) were significantly lower for ventilation, breathing frequency, HR, measures of efficiency, and CI and significantly higher for [Formula: see text], [Formula: see text] and RPE (p<0.05adjusted). For the fitness-matched subgroup, differences remained for breathing frequency, [Formula: see text], [Formula: see text], and RPE (p<0.05adjusted), and higher tidal volumes were identified for ME/CFS (p<0.05adjusted). Exercise responses at the gas exchange threshold, peak, and for measures of ventilatory efficiency (e.g., [Formula: see text]) were generally reflective of those seen throughout exercise (i.e., 20-100%).

Conclusion: Compared to fitness-matched controls, cardiopulmonary responses to exercise in ME/CFS are characterized by inefficient exercise ventilation and augmented perception of effort. These data highlight the importance of distinguishing confounding fitness effects to identify responses that may be more specifically associated with ME/CFS.

Source: Cook DB, VanRiper S, Dougherty RJ, Lindheimer JB, Falvo MJ, Chen Y, Lin JS, Unger ER; MCAM Study Group. Cardiopulmonary, metabolic, and perceptual responses during exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Multi-site Clinical Assessment of ME/CFS (MCAM) sub-study. PLoS One. 2022 Mar 15;17(3):e0265315. doi: 10.1371/journal.pone.0265315. PMID: 35290404; PMCID: PMC8923458. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8923458/  (Full text)

Lessons from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome for Long COVID Part 4: Heart Rate Monitoring to Manage Postexertional Symptom Exacerbation

The physiology underlying postexertional symptom exacerbation (PESE) is abnormal in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and likely long COVID. Activity pacing approaches appear warranted to accommodate the unusual physiological deficits of PESE.

The Rationale for Heart Rate Monitoring

Similar to people living with ME/CFS,7 people living with long COVID have reported finding activity pacing to be helpful. This idea is reflected in current safe rehabilitation guidelines for this condition.8 PESE is challenging to self-manage because of the variability in onset, duration, and nature from person to person.2,6 Social stigma associated with PESE may lead people to overexert to meet the demands of their daily tasks. This stigma may be exacerbated by people telling patients that “it’s all in their head” or they “just need to exercise.” Variability and stigma, in turn, make it difficult to identify important activity triggers in the early stages of learning to manage PESE.

PESE is characterized by aerobic system dysfunction. Pacing based on heart rate can help the patient avoid the dysfunctional aerobic system by keeping their activity intensity at a level anaerobic metabolism will dominate. Heart rate monitoring (HRM) provides an element of predictive potential for the patient to understand when their activities exceed physiological limits and eventually may result in PESE. In this post, we will discuss activity pacing to manage PESE that is based on HRM.

Source: Todd E. Davenport, Staci R. Stevens, Jared Stevens, Christopher R. Snell, J. Mark Van Ness. Lessons from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome for Long COVID Part 4: Heart Rate Monitoring to Manage Postexertional Symptom Exacerbation. Published online on February 23, 2022. https://doi.org/10.2519/jospt.blog.20220223 (Full text)