Exercise tolerance testing in a prospective cohort of adolescents with chronic fatigue syndrome and recovered controls following infectious mononucleosis

Abstract:

OBJECTIVE: Six months after acute infectious mononucleosis (IM), 13% of adolescents meet criteria for chronic fatigue syndrome (CFS). We measured exercise tolerance in adolescents with CFS and control subjects 6 months after IM.

STUDY DESIGN: Twenty-one adolescents with CFS 6 months after IM and 21 recovered control subjects performed a maximal incremental exercise tolerance test with breath-by-breath gas analysis. Values expressed are mean+/-standard deviation.

RESULTS: The adolescents diagnosed with CFS and control subjects did not differ in age, weight, body mass index, or peak work capacity. Lower oxygen consumption peak percent of predicted was seen in adolescents with CFS compared with control subjects (CFS 99.3+/-16.6 vs control subject 110.7+/-19.9, P=.05). Peak oxygen pulse also was lower in adolescents with CFS compared with recovered control subjects (CFS 12.4+/-2.9 vs control subjects 14.9+/-4.3, P=.03).

CONCLUSIONS: Adolescents with CFS 6 months after IM have a lower degree of fitness and efficiency of exercise than recovered adolescents. Whether these abnormal exercise findings are a cause or effect of CFS is unknown. IM can lead to both fatigue and measurable changes in exercise testing in a subset of adolescents.

Copyright (c) 2010 Mosby, Inc. All rights reserved.

 

Source: Katz BZ, Boas S, Shiraishi Y, Mears CJ, Taylor R. Exercise tolerance testing in a prospective cohort of adolescents with chronic fatigue syndrome and recovered controls following infectious mononucleosis. J Pediatr. 2010 Sep;157(3):468-72, 472.e1. doi: 10.1016/j.jpeds.2010.03.025. Epub 2010 May 6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2975670/ (Full article)

 

Unravelling the nature of postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: the role of elastase, complement C4a and interleukin-1beta

Abstract:

OBJECTIVES: Too vigorous exercise or activity increase frequently triggers postexertional malaise in people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a primary characteristic evident in up to 95% of people with ME/CFS. The present study aimed at examining whether two different types of exercise results in changes in health status, circulating elastase activity, interleukin (IL)-1beta and complement C4a levels.

DESIGN: Comparative experimental design.

SETTING: University.

SUBJECTS: Twenty-two women with ME/CFS and 22 healthy sedentary controls.

INTERVENTIONS: participants were subjected to a submaximal exercise (day 8) and a self-paced, physiologically limited exercise (day 16). Each bout of exercise was preceded and followed by blood sampling, actigraphy and assessment of their health status.

RESULTS: Both submaximal exercise and self-paced, physiologically limited exercise resulted in postexertional malaise in people with ME/CFS. However, neither exercise bout altered elastase activity, IL-1beta or complement C4a split product levels in people with ME/CFS or healthy sedentary control subjects (P > 0.05). Postexercise complement C4a level was identified as a clinically important biomarker for postexertional malaise in people with ME/CFS.

CONCLUSIONS: Submaximal exercise as well as self-paced, physiologically limited exercise triggers postexertional malaise in people with ME/CFS, but neither types of exercise alter acute circulating levels of IL-1beta, complement C4a split product or elastase activity. Further studying of immune alterations in relation to postexertional malaise in people with ME/CFS using multiple measurement points postexercise is required.

 

Source: Nijs J, Van Oosterwijck J, Meeus M, Lambrecht L, Metzger K, Frémont M, Paul L. Unravelling the nature of postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: the role of elastase, complement C4a and interleukin-1beta. J Intern Med. 2010 Apr;267(4):418-35. doi: 10.1111/j.1365-2796.2009.02178.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2009.02178.x/full (Full article)

 

Abnormalities in pH handling by peripheral muscle and potential regulation by the autonomic nervous system in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine muscle acid handling following exercise in chronic fatigue syndrome (CFS/ME) and the relationship with autonomic dysfunction.

DESIGN: Observational study.

SETTING: Regional fatigue service. SUBJECTS & INTERVENTIONS: Chronic fatigue syndrome (n = 16) and age and sex matched normal controls (n = 8) underwent phosphorus magnetic resonance spectroscopy (MRS) to evaluate pH handling during exercise. Subjects performed plantar flexion at fixed 35% load maximum voluntary contraction. Heart rate variability was performed during 10 min supine rest using digital photophlethysmography as a measure of autonomic function.

RESULTS: Compared to normal controls, the CFS/ME group had significant suppression of proton efflux both immediately postexercise (CFS: 1.1 +/- 0.5 mmol L(-1) min(-1) vs. normal: 3.6 +/- 1.5 mmol L(-1) min(-1), P < 0.001) and maximally (CFS: 2.7 +/- 3.4 mmol L(-1) min(-1) vs. control: 3.8 +/- 1.6 mmol L(-1) min(-1), P < 0.05). Furthermore, the time taken to reach maximum proton efflux was significantly prolonged in patients (CFS: 25.6 +/- 36.1 s vs. normal: 3.8 +/- 5.2 s, P < 0.05). In controls the rate of maximum proton efflux showed a strong inverse correlation with nadir muscle pH following exercise (r(2) = 0.6; P < 0.01). In CFS patients, in contrast, this significant normal relationship was lost (r(2) = 0.003; P = ns). In normal individuals, the maximum proton efflux following exercise were closely correlated with total heart rate variability (r(2) = 0.7; P = 0.007) this relationship was lost in CFS/ME patients (r(2) < 0.001; P = ns).

CONCLUSION: Patients with CFS/ME have abnormalities in recovery of intramuscular pH following standardised exercise degree of which is related to autonomic dysfunction. This study identifies a novel biological abnormality in patients with CFS/ME which is potentially open to modification.

 

Source: Jones DE, Hollingsworth KG, Taylor R, Blamire AM, Newton JL. Abnormalities in pH handling by peripheral muscle and potential regulation by the autonomic nervous system in chronic fatigue syndrome. J Intern Med. 2010 Apr;267(4):394-401. doi: 10.1111/j.1365-2796.2009.02160.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2009.02160.x/full (Full article)

 

Fibromyalgia and related conditions: electromyogram profile during isometric muscle contraction

Abstract:

OBJECTIVES: To evaluate electromyogram (EMG) profiles in patients with three related conditions: fibromyalgia, chronic fatigue syndrome, and depression.

METHODS: We studied 44 healthy volunteers, 22 patients with fibromyalgia, 11 patients with chronic fatigue syndrome, and 10 patients admitted for depression. The trapezius electromyogram was recorded during maximally sustained, bilateral, 90 degrees abduction of the shoulders. EMG signal frequency and amplitude were measured throughout the test.

RESULTS: In the fibromyalgia group, isometric contraction duration was significantly shorter than in the other two patient groups (P<0.001) and the EMG frequency and amplitude pattern indicated premature discontinuation of the muscle contraction. Findings in the chronic fatigue patients were similar to those in the healthy controls. The patients with depression had a distinctive EMG profile characterized by excessive initial motor-unit recruitment with a shift in the frequency spectrum.

CONCLUSIONS: Fibromyalgia was associated with a specific EMG pattern indicating premature discontinuation of the muscle contraction. Therefore, maximal voluntary muscle contraction tests may be of limited value for assessing function in fibromyalgia patients. Chronic fatigue syndrome patients had similar EMG findings to those in the healthy controls. The EMG alterations in the patients with depression were consistent with manifestations of psychomotor retardation.

Copyright 2010 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

 

Source: Maquet D, Croisier JL, Dupont C, Moutschen M, Ansseau M, Zeevaert B, Crielaard JM. Fibromyalgia and related conditions: electromyogram profile during isometric muscle contraction. Joint Bone Spine. 2010 May;77(3):264-7. doi: 10.1016/j.jbspin.2010.02.003. Epub 2010 Apr 22. https://www.ncbi.nlm.nih.gov/pubmed/20417143

 

Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study

Abstract:

OBJECTIVES: To examine the efficacy of the pain inhibitory systems in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) during two different types of exercise and to examine whether the (mal)functioning of pain inhibitory systems is associated with symptom increases following exercise.

DESIGN: A controlled experimental study.

SETTING AND SUBJECTS: Twenty-two women with ME/CFS and 22 healthy sedentary controls were studied at the Department of Human Physiology, Vrije Universiteit Brussel.

INTERVENTIONS: All subjects performed a submaximal exercise test and a self-paced, physiologically limited exercise test on a cycle ergometer. The exercise tests were undertaken with continuous cardiorespiratory monitoring. Before and after the exercise bouts, subjects filled out questionnaires to assess health status, and underwent pressure pain threshold measurements. Throughout the study, subjects’ activity levels were assessed using accelerometry.

RESULTS: In patients with ME/CFS, pain thresholds decreased following both types of exercise, whereas they increased in healthy subjects. This was accompanied by a worsening of the ME/CFS symptom complex post-exercise. Decreased pressure thresholds during submaximal exercise were associated with postexertional fatigue in the ME/CFS group (r = 0.454; P = 0.034).

CONCLUSIONS:These observations indicate the presence of abnormal central pain processing during exercise in patients with ME/CFS and demonstrate that both submaximal exercise and self-paced, physiologically limited exercise trigger postexertional malaise in these patients. Further study is required to identify specific modes and intensity of exercise that can be performed in people with ME/CFS without exacerbating symptoms.

Comment in: Chronic fatigue syndrome reflects loss of adaptability. [J Intern Med. 2010]

 

Source: Van Oosterwijck J, Nijs J, Meeus M, Lefever I, Huybrechts L, Lambrecht L, Paul L. Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study. J Intern Med. 2010 Sep;268(3):265-78. doi: 10.1111/j.1365-2796.2010.02228.x. Epub 2010 Mar 3. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2010.02228.x/full (Full article)

 

Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) patients often report symptom flare (SF) for >24 h after moderate exercise (post-ex). We hypothesized that SF is linked to increases in circulating cytokines and CD40 Ligand (CD40L). In 19 CFS patients and 17 controls, mental and physical fatigue and pain symptom ratings were obtained together with serum for 11 cytokines and CD40L before and at 0.5, 8, 24, and 48 h post-ex.

Before exercise, CFS had lower CD40L (p<.05) but similar cytokines versus controls. In subgroups based on SF at 48 h, high SF patients (n=11) increased in IL-1beta, IL-12, IL-6, IL-8, IL-10, and IL-13 (p<.05) 8 h post-ex. Low SF patients (n=8) showed post-ex decreases in IL-10, IL-13, and CD40L, and controls decreased in IL-10, CD40L, and TNFalpha (p<.05). Thus, in CFS, cytokine activity may vary directly with SF, which may explain prior inconsistent findings.

 

Source: White AT, Light AR, Hughen RW, Bateman L, Martins TB, Hill HR, Light KC. Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome. Psychophysiology. 2010 Jul 1;47(4):615-24. doi: 10.1111/j.1469-8986.2010.00978.x. Epub 2010 Mar 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4378647/ (Full article)

 

Graded exercise for chronic fatigue syndrome: too soon to dismiss reports of adverse reactions

Sir,

Given there is no formal system to report adverse reactions to non-pharmacological interventions such as graded exercise therapy (GET) for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), other sources of data need to be considered when evaluating safety. As noted by Clark & White, a large survey conducted in 2001 by the charity Action for ME found that 50% of patients who received graded exercise felt worse (1, 2). They also referred to a subsequent study by the same group suggesting that many patients might not have been treated by experienced therapists (3). However, the sample was small and, as in all surveys, therapist competence was not assessed.

A review of all the surveys conducted to date not only supports the view that a significant proportion of patients experience adverse reactions following GET, but also that it is premature to attribute those reactions to practitioner inexperience or inadequate training (1, 4). For example, the results of a recent survey conducted by the ME Association showed that of the 906 individuals who had received GET, 33.1% felt “much worse” and 23.4% judged themselves to be “slightly worse” (4). Similarly, a survey of patients who had been treated in the previous 3 years, i.e. following the refinement of the protocol as discussed by Clark & White, revealed that 34% of the 722 who had tried GET perceived themselves to be worse (5).

Without details of the training of the therapist and their fidelity to the treatment manual, one can only speculate about the factors associated with poor outcome. Nijs et al. (6) discussed some of the possible reasons. However, there are additional factors that deserve consideration when evaluating the efficacy and safety of GET. Firstly, the survey results may reflect, at least in part, the experiences of patients receiving treatment in a clinical setting. As has been shown in studies on other interventions, the outcomes documented in routine practice may be more realistic than those obtained in randomized controlled trials (7). Secondly, many patients may not be able to complete graded activity schedules for various reasons, including ongoing pathology. For instance, Black & McCully (8) used an accelerometer to measure activity levels before, during and after a 4-week “training period” consistent with GET. They documented an increase in activity counts lasting between 4 and 10 days, and this was associated with higher scores for pain and fatigue. The inability to sustain target activity levels was also noted by Friedberg (9), who followed the progress of one patient during 26 sessions of GET. He recorded a 10.6% decrease in mean weekly step counts, leading Friedberg to speculate that the subjective measures of improvement might have been the result of activity substitution and a corresponding reduction in perceived stress.

Finally, we were surprised that neither of the letters cited the research by White et al. (10). This elegant study supports the growing evidence of abnormal metabolic and immunological reactions to exercise in subsets with CFS. Although their sample was small, White et al. found elevated concentrations of the pro-inflammatory cytokine tumour necrosis factor-alpha at time-points of 3 h and 3 days after exercise. In addition, they documented increased levels of the anti-inflammatory cytokine transforming growth factor-beta after normal exertion. We therefore concur with Nijs et al. (6) as well as other researchers, that GET may not be appropriate for all patients with CFS and that pacing may provide a useful, acceptable and safe alternative (6, 11, 12).

You can read the rest of this letter here: https://www.medicaljournals.se/jrm/content/abstract/10.2340/16501977-0493

Comment on: Chronic fatigue syndrome. [J Rehabil Med. 2008]

 

Source: Kindlon T, Goudsmit EM. Graded exercise for chronic fatigue syndrome: too soon to dismiss reports of adverse reactions. J Rehabil Med. 2010 Feb;42(2):184; author reply 184-6. doi: 10.2340/16501977-0493. https://www.medicaljournals.se/jrm/content/abstract/10.2340/16501977-0493 (Full article)

 

Postexertional malaise in women with chronic fatigue syndrome

Abstract:

OBJECTIVE: Postexertional malaise (PEM) is a defining characteristic of chronic fatigue syndrome (CFS) that remains a source of some controversy. The purpose of this study was to explore the effects of an exercise challenge on CFS symptoms from a patient perspective.

METHODS: This study included 25 female CFS patients and 23 age-matched sedentary controls. All participants underwent a maximal cardiopulmonary exercise test. Subjects completed a health and well-being survey (SF-36) 7 days postexercise. Subjects also provided, approximately 7 days after testing, written answers to open-ended questions pertaining to physical and cognitive responses to the test and length of recovery. SF-36 data were compared using multivariate analyses. Written questionnaire responses were used to determine recovery time as well as number and type of symptoms experienced.

RESULTS: Written questionnaires revealed that within 24 hours of the test, 85% of controls indicated full recovery, in contrast to 0 CFS patients. The remaining 15% of controls recovered within 48 hours of the test. In contrast, only 1 CFS patient recovered within 48 hours. Symptoms reported after the exercise test included fatigue, light-headedness, muscular/joint pain, cognitive dysfunction, headache, nausea, physical weakness, trembling/instability, insomnia, and sore throat/glands. A significant multivariate effect for the SF-36 responses (p < 0.001) indicated lower functioning among the CFS patients, which was most pronounced for items measuring physiological function.

CONCLUSIONS: The results of this study suggest that PEM is both a real and an incapacitating condition for women with CFS and that their responses to exercise are distinctively different from those of sedentary controls.

Source: VanNess JM, Stevens SR, Bateman L, Stiles TL, Snell CR. Postexertional malaise in women with chronic fatigue syndrome. J Womens Health (Larchmt). 2010 Feb;19(2):239-44. doi: 10.1089/jwh.2009.1507. https://www.ncbi.nlm.nih.gov/pubmed/20095909

 

Sleep is not disrupted by exercise in patients with chronic fatigue syndromes

Abstract:

PURPOSE: Patients with chronic fatigue syndrome (CFS) report that exertion produces dramatic symptom worsening. We hypothesized this might be due to the exacerbation of an underlying sleep disorder, which we have previously demonstrated to exist.

METHODS: Female patients with CFS and matched healthy controls with no evidence of major depressive disorder were studied with overnight polysomnography on a baseline night and on a night after their performance of a maximal exercise test.

RESULTS: CFS patients as a group had evidence for disturbed sleep compared with controls. Although exercise improved sleep for healthy subjects, it did not do this for the group as a whole. When we stratified the sample on the basis of self-reported sleepiness after a night’s sleep, the patient group with reduced morning sleepiness showed improvement in sleep structure, whereas those with increased morning sleepiness continued to show evidence for sleep disruption.

CONCLUSIONS: Sleep is disturbed in CFS patients as a group, but exercise does not exacerbate this sleep disturbance. Approximately half the patients studied actually sleep better after exercise. Therefore, activity-related symptom worsening is not caused by worsened sleep.

 

Source: Togo F, Natelson BH, Cherniack NS, Klapholz M, Rapoport DM, Cook DB. Sleep is not disrupted by exercise in patients with chronic fatigue syndromes. Med Sci Sports Exerc. 2010 Jan;42(1):16-22. doi: 10.1249/MSS.0b013e3181b11bc7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796587/ (Full article)

 

Polysaccharide of radix pseudostellariae improves chronic fatigue syndrome induced by poly I:C in mice

Abstract:

Radix Pseudostellariae is used as a tonic drug in traditional Chinese medicine with immunomodulating and anti-fatigue activities, and the polysaccharide is considered as the main active component. The purpose of this study is to examine the effect of the polysaccharide isolated from Radix Pseudostellariae (PRP) on mouse chronic fatigue syndrome (CFS) induced by intraperitoneal injection of polyriboinosinic:polyribocytidylic acid (poly I:C), a double-stranded synthetic RNA.

It has shown that the fatigue symptom of mice lasted at least 1 week as evaluated by forced swimming time. PRP (100, 200, 400 mg kg(-1)), orally administered 3 days before poly I:C injection, showed dose-dependent anti-fatigue effects.

In addition, poly I:C led to evident alterations in neuroendocrine and immune systems of mice, such as reduced spontaneous activity and learning ability, declined serum level of corticosterone, increased weight indexes and T lymphocyte numbers in thymuses and spleens, and increased CD4(+)/CD8(+) ratio but decreased proliferation ability of T lymphocytes in spleens. PRP alleviated the abnormalities caused by poly I:C, and restored the function of hosts to normal conditions.

The findings suggest that PRP is beneficial to CFS, and the underlying mechanisms of action involve neuroendocrine and immune systems.

 

Source: Sheng R, Xu X, Tang Q, Bian D, Li Y, Qian C, He X, Gao X, Pan R, Wang C, Luo Y, Xia Y, Dai Y. Polysaccharide of radix pseudostellariae improves chronic fatigue syndrome induced by poly I:C in mice. Evid Based Complement Alternat Med. 2011;2011:840516. doi: 10.1093/ecam/nep208. Epub 2011 Jun 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3137695/ (Full article)