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Reproducibility of Measurements Obtained During Cardiopulmonary Testing in Individuals With Fatiguing Health Conditions - Larson, Snell, Davenport ..

Discussion in 'BioMedical ME/CFS Research' started by Kalliope, Aug 28, 2019.

  1. Kalliope

    Kalliope Senior Member (Voting Rights)

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    Cardiopulmonary Physical Therapy Journal
    Reproducibility of Measurements Obtained During Cardiopulmonary Exercise Testing in Individuals With Fatiguing Health Conditions - Benjamin Larson, Todd Davenport, Staci Stevens, Jared Stevens, Mark Van Ness, Christopher Snell

    Purpose: Measurements obtained during maximal cardiopulmonary exercise testing (CPET) demonstrate high test–retest reliability, which indicates low error variance. However, measurements obtained from people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) may depart from typically observed high reproducibility, which could represent functionally relevant biological variability that is characteristic of the underlying pathophysiology. The purpose of this case series was to document individual experiences with test–retest variability in CPET measurements in individuals with ME/CFS compared with other fatiguing health conditions.

    Methods: In this case series, 6 women matched for age and body mass index underwent 2 maximal CPETs spaced 24 hours apart. Clients comprised 1 sedentary individual without fatigue, 1 active individual without fatigue, 1 individual with multiple sclerosis (MS), 1 individual diagnosed with HIV, 1 individual with ME/CFS and low maximal volume of oxygen consumed (VO2max), and 1 high-functioning individual with ME/CFS and high VO2max. Percent change in CPET measurements between tests was calculated for each client.

    Results: Nondisabled clients and clients with MS and HIV reproduced or improved in their volume of oxygen consumed (VO2), workload (WL), heart rate (HR), and minute ventilation (VE) at ventilatory anaerobic threshold (VAT) and at peak exercise (except peak WL and VE for the individual with HIV). Neither individual with ME/CFS reproduced VO2, WL, HR, or VE at VAT within literature estimates.

    Conclusions: Measurements during CPET for individual patients may relate to potential condition-specific deficits in cardiac, pulmonary, and metabolic functioning.

     
    andypants, sea, alktipping and 28 others like this.
  2. Kalliope

    Kalliope Senior Member (Voting Rights)

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  3. ScottTriGuy

    ScottTriGuy Senior Member (Voting Rights)

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    is this individual with HIV on meds?

    My first assumption was the authors assumed living with HIV (and treatment) was de facto a fatiguing condition.

    Also curious why the WL and VE did not increase for HIV+?
     
    alktipping and Annamaria like this.
  4. strategist

    strategist Senior Member (Voting Rights)

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    Do the medications cause fatigue or reduce it?

    I know almost nothing about HIV but I have the vague memory that one or some antiretroviral medications used to treat it cause fatigue, perhaps by interfering with mitochondrial function.
     
  5. adambeyoncelowe

    adambeyoncelowe Senior Member (Voting Rights)

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    Yes, Truvada, the main ARV in HIV, can cause fatigue (and liver damage, IIRC).
     
    MEMarge, Grigor, alktipping and 5 others like this.
  6. Simon M

    Simon M Senior Member (Voting Rights)

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    Good to see this published. Case reports are a very low grade evidence, so the key point from the Workwell tweet is "now to get funding and test with larger numbers."
     
    lycaena, andypants, MEMarge and 16 others like this.
  7. Trish

    Trish Moderator Staff Member

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    I think they have done something very useful here as a starting point for funding future research. I like that they are looking at different groups to compare, not just ME and healthy. Adding people with other long term conditions seems a very good strategy.
     
    lycaena, andypants, MEMarge and 13 others like this.
  8. ScottTriGuy

    ScottTriGuy Senior Member (Voting Rights)

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    I have a close friend who experiences 'chronic fatigue' (not 'cfs') and it is from his HIV meds. When he's not on them, he does not experience fatigue.

    Fortunately, a pharmacist (when physicians failed to care or take action) noted that all his HIV meds had one particular ingredient (my friend could not remember what that was), and when he switched to ARVs without that ingredient, the intensity of his chronic fatigue lessened considerably. Now he complains that has an extra 4 hours a day awake instead of sleeping :).

    My friend is also an atypical responder to most medications.

    I've worked with a lot of people living with HIV, I can only recall one other patient with fatigue, and his was specific to standing (his legs would get fatigued) - did that have anything to do with his ARVs, don't know.

    Fwiw, I've personally been on over half a dozen different HIV meds, and I never experienced fatigue. Lots of nausea (especially from AZT), but even then (before ME obviously) I would go for an easy run or bike and 90+% of the time it would alleviate the nausea...weird eh?
     
    MEMarge, Snow Leopard, Grigor and 9 others like this.
  9. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Has anyone read this paper yet?

    Besides the obvious, it is notable that the reduction in workload and VO2 at the ventilatory threshold still occurred in the high-functioning individual with ME/CFS and high VO2max. So it seems fitness doesn't matter.

    I'd like to see the actual results though.
     
    ahimsa, Trish, Amw66 and 2 others like this.

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