Physical activity measures in patients with ME/CFS: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, & the number of steps from an activity meter

Physical activity measures in patients with myalgic encephalomyelitis/chronic fatigue syndrome: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, and the number of steps from an activity meter, by CMC van Campen, Peter C Rowe, Freek WA Verheugt & Frans C Visser in Journal of Translational Medicine vol 18, no. 228 (2020) [doi.org/10.1186/s12967-020-02397-7]

 

Research abstract:

Background:

Most studies to assess effort intolerance in patients with myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) have used questionnaires. Few studies have compared questionnaires with objective measures like an actometer or an exercise test. This study compared three measures of physical activity in ME/CFS patients: the physical functioning scale (PFS) of the SF-36, the number of steps/day (Steps) using an actometer, and the %peak VO2 of a cardiopulmonary stress test.

Methods:

Female ME/CFS patients were selected from a clinical database if the three types of measurements were available, and the interval between measurements was ≤ 3 months. Data from the three measures were compared by linear regression.

Results:

In 99 female patients the three different measures were linearly, significantly, and positively correlated (PFS vs Steps, PFS vs %peak VO2 and Steps vs %peak VO2: all P < 0.001). Subgroup analysis showed that the relations between the three measures were not different in patients with versus without fibromyalgia and with versus without a maximal exercise effort (RER ≥ 1.1).

In 20 patients re-evaluated for symptom worsening, the mean of all three measures was significantly lower (P < 0.0001), strengthening the observation of the relations between them. Despite the close correlation, we observed a large variation between the three measures in individual patients.

Conclusions:

Given the large variation in ME/CFS patients, the use of only one type of measurement is inadequate. Integrating the three modalities may be useful for patient care by detecting overt discrepancies in activity and may inform studies that compare methods of improving exercise capacity.

Study conclusion:

Disability grading or activity assessment in ME/CFS is most frequently performed using questionnaires like the physical functioning scale of the SF-36. Questionnaires can be augmented by adding more objective measures such as the number of steps on an activity meter and/or by adding peak VO2 data.

The relation between the physical functioning scale and the number of steps, and the relation between activity (steps), perceived activity (physical functioning scale) and the maximum attainable activity (peak VO2) may give insight into a possible over- or under-estimation of the perceived activity and over- or under-performance of physical activities.

Whether a better “energy management” leads to stabilization or improvement over time of patients needs to be studied. Finally, the presented standard deviations may aid the design of outcome studies.

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Health-related quality of life in Norwegian adolescents living with CFS

Health-related quality of life in Norwegian adolescents living with Chronic Fatigue Syndrome, by  Wenche Ann Similä, Vidar Halsteinli, Ingrid B Helland, Christer Suvatne, Hanna Elmi, Torstein Baade Rø in Health Qual Life Outcomes. 2020 Jun 5;18(1):170 [doi: 10.1186/s12955-020-01430-z]

 

Research abstract:

Purpose: The primary aim was to measure health related quality of life (HRQoL) in a Norwegian cohort of adolescents with Chronic Fatigue Syndrome (CFS/ME). A secondary aim was to identify factors before diagnosis, at time of diagnosis and after diagnosis that were associated with HRQoL.

Methods: In this cross-sectional population-based study, HRQoL was measured by Pediatric Quality of Life Inventory™ Generic Core scale version 4.0 (PedsQL4.0) in 63 adolescents with CFS/ME. In addition, fatigue was measured by PedsQL Multidimensional Fatigue scale (PedsQL-MFS), depressive symptoms were measured by the Short Mood and Feelings Questionnaire (SMFQ), and disruption in school activities was measured by The De Paul Pediatric Health Questionnaire (DPHQ-N). Data were also collected from medical records and patient interviews.

Results: Age at diagnosis was 15 (2) years (mean (SD)), and four out of five participants were female. Time from diagnosis to reply was 39 (22) months. Adolescents with CFS/ME reported PedsQL4.0 score 50 (17), and boys reported a better score than girls (64 vs 47, 95% Confidence Interval (CI) for difference (- 27; – 6)).

Factors found with association to HRQoL in adolescents living with CFS/ME

There were positive associations between overall HRQoL and support from a schoolteacher, school attendance or participation in leisure activities. There were negative associations between overall HRQoL and delayed school progression, having been to rehabilitation stay and depressive symptoms.

Conclusion: HRQoL in adolescents diagnosed with CFS/ME was low. The associations between reported HRQoL, healthcare previously provided, support from a schoolteacher, school attendance and participation in leisure activity may provide information of value when developing refined strategies for healthcare among adolescents with CFS/ME. Possible causal relationships must however be explored in future studies.

Research paper conclusion

In this cross-sectional study of adolescents with CFS/ME we found low HRQoL. The study identified new and possibly important factors associated with HRQoL. When exploring factors before, at the time of or after diagnosis associated with HRQoL, we found that school attendance, support from a schoolteacher and participation in leisure activities were associated with higher HRQoL. We also found associations to higher emotional functioning, when occupational therapist, physical therapist and clinical nutritionist were engaged in diagnostic evaluation.

On the other hand, school absence higher than 50% before diagnostic evaluation, delayed school progression or having been to a rehabilitation stay were negatively associated with HRQoL. Early diagnosis, mapping of symptoms severity and HRQoL, maintaining school contact and early action to prevent depressive symptoms might be important to improve HRQoL in these patients.

Limitations to our study design imply that future interventional studies are needed to confirm whether the identified factors can be used to improve HRQoL in adolescents with CFS/ME.

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The Health Minister, Covid-19, ME, rehabilitation & NICE

The Health Minister comments on Covid-19, ME, rehabilitation & NICE

 

The Health Minister Vaughan Gething has replied to the letter WAMES sent to him on International ME Awareness Day highlighting the links between Covid-19, PVFS and ME, and requesting a combined strategy for care.  We note that the forthcoming guidance on rehabilitation “will not be condition specific” so WAMES will be ensuring rehabilitation practitioners are informed about the dangers of exercise intolerance for people with ME, PVFS and potentially Covid-19 survivors.

 

4 June 2020

Dear Jan,

Thank you for your letter of 13 May regarding the care for people with COVID-19 and ME, and calling for a strategy to recognise and treat illnesses triggered by all viruses. I note this letter was also issued to Andrew Goodall. [DG of NHS Wales]

The Welsh Government recognises the important role that effective rehabilitation has in reducing the physical, psychological, emotional, social and economic impacts of both COVID-19 and non COVID-19 related illness. That is why we are developing national guidance to assist service planning for the anticipated demand for rehabilitation and recovery of both COVID-19 and non-COVID-19 populations in adults and children.

This work is being undertaken by the multi-professional, multi-sector Rehabilitation Task and Finish group and is currently in the process of being finalised. Two specific rehabilitation frameworks will underpin this: one identifying rehabilitation needs for those recovering from COVID-19 and one for the wider population with continuing or new rehabilitation needs. Rehabilitation focusses on the impact for the person and ways of resolving those impacts, rather than the condition that causes the impact and so the rehabilitation guidance and frameworks will not be condition specific.

With regards to NICE guidance, the Welsh Government has previously acknowledged your concerns regarding this and I reiterate that NICE guidance remains extant and should be followed by clinicians in Wales until such time that they are revoked or replaced.

You have also requested that ME/CFS be added to the shielded list. The main criteria for inclusion in the shielded list is that people from this group would be more likely to have a significantly higher death rate as a direct consequence of their condition. There is no clear evidence that this is, or would be, anticipated to be the case for this group of individuals, and as such they have not been included. If in due course, significant evidence does emerge this will be considered by the Chief Medical Officers across the four Nations.

Finally, the Welsh Government proposal to combine persistent pain, arthritis, ME/CFS and fibromyalgia into one advisory group will support both common approaches to these conditions where feasible, whilst also ensuring that condition specific approaches are maintained where required. However, we will review this approach as part of our wider approach to health and social care recovery from COVID-19.

Yours sincerely,

Vaughan Gething AS/MS
Y Gweinidog Iechyd a Gwasanaethau Cymdeithasol
Minister for Health and Social Services

CC: Andrew Goodall

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The concept of ‘illness without disease’ impedes understanding of CFS: a response to Sharpe & Greco

The concept of ‘illness without disease’ impedes understanding of chronic fatigue syndrome: a response to Sharpe and Greco, by Steven Lubet, David Tuller in BMJ Medical Humanities. Published Online First: 01 June 2020. [doi: 10.1136/medhum-2019-011807]

 

Article abstract:

In a recent article in Medical Humanities, Sharpe and Greco characterise myalgic encephalomyelitis/  chronic fatigue syndrome (ME/CFS) as an ‘illness without disease’, citing the absence of identified diagnostic markers.

They attribute patients’ rejection of psychological and behavioural interventions, such as cognitive–behavioural therapy (CBT) and graded exercise therapy (GET), to a ‘paradox’ resulting from a supposed failure to acknowledge that ‘there is no good objective evidence of bodily disease’.

In response, we explain that understandings about the causes of and treatments for medical complaints have shifted across centuries, and that conditions once thought to be ‘psychosomatic’ have later been determined to have physiological causes.

We also note that Sharpe and Greco do not disclose that leading scientists and physicians believe that ME/CFS is a biomedical disease, and that numerous experts, not just patients, have rejected the research underlying the CBT/GET treatment approach.

In conclusion, we remind investigators that medical classifications are always subject to revision based on subsequent research, and we therefore call for more humility before declaring categorically that patients are experiencing ‘illness without disease’.

Read full article

Read summary of article by Steven Lubet: Is ME/CFS an “Illness without Disease”?

No. No it is not. No matter what certain psychiatrists have opined..

…Given psychiatry’s long history of mistaken theories of disease
causation, there is an almost wondrous grandiosity to Sharpe and
Greco’s proposed solution to the supposed “paradox” that troubles
them. Rather than conceding that CBT and GET may be failed therapies
for ME/CFS, and that biomedical research may ultimately hold the key,
they instead call for “a major long-term change in thinking” on the
part of patients, clinicians and scientists who do not share their
particular views regarding the “moral connotations of illness and
disease”.

The illness-without-disease concept can be a useful tool in
exploring interactions between patients and health care systems, but
only if it is recognized as highly contingent and subject to the
admitted limitations of current knowledge. Contra Sharpe and Greco,
patients would be better served by greater humility accompanied by an
understanding that medical categories are always provisional and
therefore subject to change with advances in research.

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Metabolic dysfunction in ME/CFS not due to anti-mitochondrial antibodies

Metabolic dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome not due to anti-mitochondrial antibodies, by Isabell Nilsson, Jeremy Palmer, Eirini Apostolou, Carl-Gerhard Gottfries, Muhammad Rizwan, Charlotte Dahle and Anders Rosén in Front. Med., 31 March 2020 [doi.org/10.3389/fmed.2020.00108 ]

 

Research abstract:

Metabolic profiling studies have recently indicated dysfunctional mitochondria in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This includes an impaired function of pyruvate dehydrogenase complex (PDC), possibly driven by serum factor(s), which leads to inadequate adenosine triphosphate generation and excessive lactate accumulation. A reminiscent energy blockade is likely to occur in primary biliary cholangitis (PBC), caused by anti-PDC autoantibodies, as recently proposed. PBC is associated with fatigue and post-exertional malaise, also signifying ME/CFS.

We herein have investigated whether ME/CFS patients have autoreactive antibodies that could interfere with mitochondrial function. We found that only 1 of 161 examined ME/CFS patients was positive for anti-PDC, while all PBC patients (15/15) presented significant IgM, IgG, and IgA anti-PDC reactivity, as previously shown. None of fibromyalgia patients (0/14), multiple sclerosis patients (0/29), and healthy blood donors (0/44) controls showed reactivities. Anti-mitochondrial autoantibodies (inner and outer membrane) were negative in ME/CFS cohort. Anti-cardiolipin antibody levels in patients did not differ significantly from healthy blood donors.

In conclusion, the impaired mitochondrial/metabolic dysfunction, observed in ME/CFS, cannot be explained by presence of circulating autoantibodies against the tested mitochondrial epitopes.

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Modeling disability: softly making the invisible visible

Modeling disability: softly making the invisible visible, by Libby Evan (2020) Bachelor of Fine Arts Senior Papers 74

 

Research abstract:

“I am not asking for pity. I am telling you about my disability.” – Eli Clare1

In the following Bachelor of Fine Arts thesis statement, you will not find someone overcoming their disability. You will not find a tale of inspiration. You will not find a cure for ableism. You 2 simply will find an individual’s experience of disability— my experience of disability.

Impossible stairs

My invisible disability puts the medical model and social model of disability in constant tension as I navigate everyday life living with Chronic Fatigue Syndrome and severe arthritis. Both models seek to find blame for disability, whether in searching for a medical cure for illness or putting blame on society at large for creating barriers. Instead of abiding by these limiting models, I cope with disability in my own way. I embrace the contradictory notion of having significant physical limitations while giving into the pressures of our capitalist society to physically produce.

I make my own models through accepting my identity and embracing the human-like, huggability of soft sculpture. As a sculptor, I do not need to find blame through theoretical models of disability. Instead, I make literal models representing my lived experience. I turn my invisible, private experiences into visible, public ones.

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Sleep problems in adolescents with CFS: a case-control study nested within a prospective clinical cohort

Sleep problems in adolescents with CFS: A case-control study nested within a prospective clinical cohort, by Maria Elizabeth Loades, Katharine A Rimes, Trudie Chalder in Clinical Child Psychology and Psychiatry, May 22 2020 [doi.org/10.1177/1359104520918364]

 

Research abstract:

Sleep problems have a negative impact on a range of outcomes and are very common in adolescents with chronic fatigue syndrome (CFS). We aimed to (a) establish whether adolescents with CFS have more self-reported sleep problems than illness controls as well as healthy controls, (b) investigate changes in sleep problems and (c) explore the extent to
which sleep problems at baseline predict fatigue and functioning at follow-up in adolescents with CFS.

The Insomnia Scale was completed by 121 adolescents with CFS, 78 healthy adolescents and 27 adolescents with asthma. Eighty (66%) treatment-naive adolescents with CFS completed questionnaires approximately 3 months later.

Adolescents with CFS reported increased sleep problems compared to healthy controls and adolescents with asthma. In CFS, there was no significant change in sleep problems without treatment over a 3-month follow-up. Sleep problems at baseline predicted a significant proportion of the variance in sleep problems at follow-up. Sleep problems should be targeted in treatment. Regulating the ‘body clock’ via the regulation of sleep could influence outcomes not assessed in this study such as school attainment.

Read full paper

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Review of the quality control checks performed by current genome-wide & targeted-genome association studies on ME/CFS

Review of the quality control checks performed by current genome-wide and targeted-genome association studies on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, by Nuno Sepulveda, Anna D Grabowska, Eliana M Lacerda, Luis C Nacul in Frontiers in Pediatrics. May 7, 2020 [doi: 10.3389/fped.2020.00293 ]

 

Research article Introduction:

Myalgic encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating disease characterized by persistent fatigue and post-exertion malaise, accompanied by other symptoms. The direct cause of the disease remains elusive, but it may include genetic factors alongside environmental triggers, such as strong microbial infections and other stressors.

Aiming to identify putative genetic factors that could explain the pathophysiological mechanisms of ME/CFS, four genome-wide association studies (GWAS) and two targeted-genome association studies (TGAS) were conducted in the past decade (5–10). In the four GWAS, thousands of genetic markers located across the whole genome were evaluated for their statistical association with ME/CFS (5–8). The two TGAS had the same statistical objective of the four GWAS, but alternatively investigated the association of the disease with numerous genetic markers located in candidate genes related to inflammation and immunity (9) and in genes encoding diverse adrenergic receptors (10).

The findings from all these different studies suggested conflicting evidence of genetic association with ME/CFS: from absence of association (7), through mild association (10) up to moderate associations of a relatively small number of genetic markers (5,6,9). The most optimistic GWAS suggested more than 5,500 candidate gene-disease associations (8).

This inconsistency in the reported findings prompted us to review the respective data. With this purpose, the present opinion paper first revisits the recommended quality control (QC) checks for GWAS and TGAS, and then summarizes which ones were performed by those studies on ME/CFS…

Discussion

This opinion paper shows partial QC checks in the majority of the published genetic association studies on ME/CFS, the exception being the study carried out by Herrera et al (7). The assessment of the performed QC checks is essential to ascertain the quality of the respective genetic data. In this regard, the genetic data from Perez et al (8) deserves to be further analysed to ascertain the validity of the reported findings. Such assessment can follow the QC steps outlined here and exemplary performed by Herrera et al (7). The remaining studies can also benefit by an additional quality check related to heterozygosity rate so that possible sample contaminations can be ruled out.

The absence of this check does not immediately invalidate the genetic data of these studies. We could have done such check if the corresponding genetic data were available either in an open-access repository or as a supplementary file within the respective publication, a data-sharing practice followed by several ME/CFS researchers (13–15).

Consequently, it is unclear whether aberrant heterozygosity rates (due to sample contamination) are one of the explanations for the conflicting evidence of genetic associations reported by these studies. In this regard, Herrera et al (7) excluded five out of their 109 samples (5%) based on the heterozygosity rate. In simple statistical applications using large sample sizes, a 5% sample contamination might be too low to have a substantial impact on the respective findings. However, in the specific context of GWAS and TGAS where stringent significance levels are used to control for multiple testing, such a level of sample contamination could reduce the underlying statistical power and leave relevant disease-gene associations undetected.

Besides the partial QC checks, the investigated genetic data on ME/CFS suffer from the curse of not having an objective biomarker for disease diagnosis. Similar problem can be envisioned for other complex diseases lacking a biomarker, such as Fibromyalgia and the Gulf War Syndrome. The absence of a biomarker is likely to introduce a possible misclassification of the true disease status of the recruited patients (16). To illustrate this putative problem, Herrera et al (7) recruited nine obese (with body mass indexes equal or higher than 35 kg/m2) out of 61 patients based on the Centre for Diseases Control Criteria (1) and Canadian Consensus Criteria (2). Notwithstanding controlling for the body mass index in the respective association analysis and the exclusion of known diseases, it is unclear whether the obesity observed in these patients was a direct consequence of ME/CFS or instead caused by another ongoing disease strongly associated with fatigue.

A solution to this problem is to use more advanced statistical methodology where misclassification can be directly included in the data analysis (17,18). However, given the complexity of this methodology, we argue that a stronger collaboration between the ME/CFS research community and statistical geneticists should be reached. In principle, this collaboration is expected to promote better statistical analyses, to improve data interpretations and, ultimately, a better assessment of the genetic component in ME/CFS.

In summary, given the partial QC checks performed in current GWAS and TGAS, the question of a genetic component in ME/CFS remains open for investigation. To accelerate the discovery of promising disease-gene association, future genetic studies of ME/CFS should set data and methodological standards as high as those followed by the 1000 Human Genome Project and the UK10K project (19,20). Data sharing should also be a general practice to provide the researcher community the opportunity to perform additional checks or alternative analyses of the same data.

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Systematic review of the epidemiological burden of ME/CFS across Europe: current evidence & EUROMENE research recommendations for epidemiology

Systematic review of the epidemiological burden of ME/CFS across Europe: current evidence and EUROMENE research recommendations for epidemiology, by Fernando Estévez-López, Kathleen Mudie, Xia Wang-Steverding, Inger Johanne Bakken, Andrejs Ivanovs, Jesús Castro-Marrero, Luis Nacul, Jose Alegre, Paweł Zalewski, Joanna Słomko, Elin Bolle Strand, Derek Pheby, Evelina Shikova, Lorenzo Lorusso, Enrica Capelli, Slobodan Sekulic, Carmen Scheibenbogen, Nuno Sepúlveda, Modra Murovska, and Eliana Lacerda, on behalf of The European Network on ME/CFS (EUROMENE) in J. Clin. Med. 2020, 9 (5), 1557; [https://doi.org/10.3390/jcm9051557]

 

Review abstract:

This review aimed at determining the prevalence and incidence of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) in Europe. We conducted a primary search in Scopus, PubMed and Web of Science for publications between 1994 and 15 June 2019 (PROSPERO: CRD42017078688).

Additionally, we performed a backward- (reference lists) and forward-(citations) search of the works included in this review.

Grey literature was addressed by contacting all members of the European Network on ME/CFS (EUROMENE). Independent reviewers searched, screened and selected studies, extracted data and evaluated the methodological and reporting quality.

For prevalence, two studies in adults and one study in adolescents were included. Prevalence ranged from 0.1% to 2.2%. Two studies also included incidence estimates. In conclusion, studies on the prevalence and incidence of ME/CFS in Europe were scarce.

Our findings point to the pressing need for well-designed and statistically powered epidemiological studies.

To overcome the shortcomings of the current state-of-the-art, EUROMENE recommends that future research is better conducted in the community, reviewing the clinical history of potential cases, obtaining additional objective information (when needed) and using adequate ME/CFS case definitions; namely, the Centers for Disease Control & Prevention−1994, Canadian Consensus Criteria, or Institute of Medicine criteria

Excerpt from Conclusions:

Potential causes of this paucity of knowledge may be due to a European lack of (i) official disease recognition, (ii) consensus over case definitions, or (iii) investment by funding agencies, among others.

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Heart rate thresholds to limit activity in ME/CFS patients (pacing): comparison of heart rate formulae

Heart rate thresholds to limit activity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients (Pacing): Comparison of heart rate formulae and measurements of the heart rate at the lactic acidosis threshold during Cardiopulmonary Exercise Testing, by C (Linda) MC van Campen, Peter C Rowe, Frans C Visser in Advances in Physical Education Vol. 10 No.2, May 2020 [DOI: 10.4236/ape.2020.102013]

 

 

Research abstract:

Introduction:

Based on the hypothesis that oxidative metabolism is impaired in ME/CFS, a previous study recommended a pacing self-management strategy to prevent post-exertional malaise. This strategy involved a prescription to maintain a heart rate below the anaerobic threshold during physical activities. In the absence of lactate sampling or a cardiopulmonary exercise test (CPET), the pacing self-management formula defines 55% of the age-specific predicted maximal heart rate as the heart rate at the anaerobic threshold. Thus far there has been no empiric evidence to test this self-pacing method of predicting heart rate at anaerobic threshold.

The aim of this study was to compare published formula-derived heart rates at the anaerobic threshold with the actual heart rate at the lactic acidosis threshold as determined by CPET.

Methods and Results:

Adults with ME/CFS who had undergone a symptom-limited CPET were eligible for this study (30 males, 60 females). We analysed males and females separately because of sex-based differences in peak oxygen consumption. From a review paper, formulae to calculate maximal predicted heart rate were used for healthy subjects. We compared the actual heart rate at the lactic acid threshold during CPET to the predicted heart rates determined by formulae. Using Bland-Altman plots, calculated bias: the mean difference between the actual CPET heart rate at the anaerobic threshold and the formula predicted heart rate across several formulae varied between -28 and 19 bpm in male ME/CFS patients. Even in formulae with a clinically acceptable bias, the limits of agreement (mean bias ± 2SD) were unacceptably high for all formulae. For female ME/CFS patients, bias varied between 6 and 23 bpm, but the limits of agreement were also unacceptably high for all formulae.

Conclusion:

Formulae generated in an attempt to help those with ME/CFS exercise below the anaerobic threshold do not reliably predict actual heart rates at the lactic acidosis threshold as measured by a cardiopulmonary exercise test. Formulae based on age-dependent predicted peak heart rate multiplied by 55% have a wide age-specific variability and therefore have a limited application in clinical practice.

 

Todd Davenport of the Workwell Foundation responded to the conclusions of this study on twitter:

Todd Davenport‏ @sunsopeningband May 23

I think it’s important to point out the equation we proposed was never intended to accurately predict heart rate at VAT. It was intended to slightly under-estimate heart rate at ventilatory anaerobic threshold. The thought was this underestimation would provide a safety margin.

The authors of the present study, very helpfully, provide us with some important subject-level data in Figure 1. These data can help us get an idea of whether the formula we proposed in 2010 actually underestimates the heart rate at lactic acid threshold, as originally intended…

“All models are wrong. Some models are useful.” Formula based estimation for metabolic output using heart rate is fraught. We know there are additional problems with it from our work on chronotropic intolerance in #MECFS.

However, because (repeat) CPET measurements is still not a common evaluative assessment for people with #MECFS, patients and their physical therapists are left with few objective tools to monitor activity in our collective attempt to reduce post-exertional neuroimmune exhaustion.

Calculated values, for all their acknowledged problems with picking accurate values in single patients, still can be useful to help patients and clinicians select appropriate activity thresholds for pacing self management. The data from this study seems to support this premise.

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