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Baraniuk, 2012: Dyspnea in Chronic Fatigue Syndrome (CFS): Comparison of Two Prospective ...

Discussion in 'Latest ME/CFS Research' started by WillowJ, Mar 5, 2013.

  1. WillowJ

    WillowJ Senior Member

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    Ravindran M, Adewuyi O, Zheng Y, Rayhan RU, Le U, Timbol C, Merck S, Esteitie R, Read C, Cooney M, Baraniuk J.
    Dyspnea in Chronic Fatigue Syndrome (CFS): Comparison of Two Prospective Cross-Sectional Studies.
    Glob J Health Sci. 2012 Dec 12;5(2):94-110. doi: 10.5539/gjhs.v5n2p94.
    Georgetown University Medical Center.
    http://www.ncbi.nlm.nih.gov/pubmed/23445698

    full text (free)
    http://www.ccsenet.org/journal/index.php/gjhs/article/view/22240/14809
     
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  2. WillowJ

    WillowJ Senior Member

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    Aside from the deconditioning, those are good ideas for further assessments.
     
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  3. Valentijn

    Valentijn Activity Level: 3

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    I doubt they'll find anything useful ... their "conclusion" said it all: if it's not typical shortness of breath, it must be "hypersensitivity". No consideration for other potential mechanisms, like OI - where we might be breathing fine but be getting less oxygen to the brain. They're assuming that the excess of pain in CFS patients is caused by hypersensitivity, and that the dyspnea, unexplained by the other limited factors they looked at, must be caused hypersensitivity as well, since pain gets worse when dyspnea does. They're ignoring a myriad of other possibilities, and focusing on hypersensitivity even though there's no basis for a link between pain and hypersensitivity in this study, and in fact no mention of hypersensitivity at all except in the conclusion!

    A correlation between SF-36 physical functioning and dyspnea is also generally down-played - they mention the "relatively low" score of healthy sedentary controls in the same paragraph to conclude that dyspnea is unrelated. Seems like a bit of a spin job since physical functioning is 41.8 and 49.0 for the CFS patients and 74.0 and 71.8 for the controls.

    Also a lot of focus on psychiatric questionnaires and correlations between those scores on physical symptoms. They seem aware of the physical symptoms being reported, and levels of disability, yet chose questionnaires that are quite inappropriate in determining mood disorders in disabled patients - BDI and CES-D are terrible questionnaire choices where physical symptoms = psychological disorder, and STAI-Y1 isn't much better due to many somewhat vague questions about how the patient feels, which might be attributable to either physical or psychological causes.

    Their selection of patients and controls seems weird as well ... either I'm misunderstanding the proper use of "prospective" or they're grossly misusing the word. They weren't following a large group of random people to see who ends up with CFS based on questionnaire results from 10 years earlier ... they just took a large group of random people and diagnosed them as CFS or healthy and sedentary. I think their use of "prospective" might be ultimately over-stating their presumptions of cause and effect, with regards to hypersensitivity causing dyspnea.

    Their science does seem pretty solid, but looking at their assumptions (the questionnaires they use) and their rather baseless conclusion, they're approaching CFS with the view that it is a psychological disorder. Some of their results (lack of correlation between dyspnea and depression/anxiety) might wake them up a bit, but based on their conclusion they're almost certainly going to stay in the "CFS symptoms are not directly caused by physiological abnormality" camp and, at best, conclude that some psychological or physiological problem causes us to experience subjective symptoms and our bodies are actually functional if we learn to ignore those symptoms.
     
  4. biophile

    biophile Places I'd rather be.

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    I only had a quick look, but the "prospective" part seems to be in reference to where the subjects were sourced (from previous prospective studies) rather than this study itself being prospective?

    Is dyspnea (breathing difficulties) mainly caused by airflow restrictions and obstructions? Valentijn already mentioned an instance where breathing fine is less oxygen is getting to the brain due to OI (which may induce the air hunger sensation?). This also reminds me of research into abnormal oxygen delivery in CFS. Imbalances in O2 or CO2 may also affect dyspnea even if breathing is normal?

    From my own experience and that of others, post-exertional symptoms can also include increased difficulties for the muscles to work properly under load. So for breathing, it literally feels more labored or strained because the muscles responsible are working harder than their comfortable capacity (Wikipedia writes that labored breathing is distinct from but often confused with dyspnea). Interestingly, the study authors wrote this:

    The authors may argue that post-exertional symptoms are also due to "hypersensitivity" and even deconditioning (but how many healthy sedentary people still feel short of breath 24-48 hours after the exertion in question as some patients do?).
     
  5. taniaaust1

    taniaaust1

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    If Willows quote below came from the study (which Im assuming it did unless someone tells me otherwise..full studies too hard for me to read) they cant be saying this is being caused by deconditioning. "related declines in fitness were not responsibe"

    Seeing they've come up with dyspnea doesnt seem to be related to finess level, nor to anxiety (how many doctors tell CFS people that breathing problems are related to anxiety?". I personally think this study is a useful one to dispute some of the crap we so often hear
     
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  6. WillowJ

    WillowJ Senior Member

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    (have edited to make it clear the quotes did come from the study)

    specifically, they said "age-related declines in fitness were not responsible" and "poor quality of life ... [was] not responsible". But if ageing isn't related, and PWCs are unlike sedentary controls, it seems extremely unlikely deconditioning could have anything to do with it. (besides.) Not sure whether QOL is meant to mean merely anxiety/depression or also the effect of being sick and not able to do much, which would rule out deconditioning.
     
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  7. August59

    August59 Daughters High School Graduation

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    Dypsnea or air hunger is fairly frequent but in no way is it's severity a timely thing or a duration of symptoms no better than a 50% chance of it being present at any one time. It could be every other week for 3 day sto 15 days and no present itself again for 3 months and last 4 or 5 days and gone again for 2 months then be present for a month.

    Maybe they were able to screen and catch the CFS patients at a time of significant dysnea. Hope so anyway!
     
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  8. Dolphin

    Dolphin Senior Member

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    For what it's worth, this is a submission James Baraniuk made to the FDA process on #ME and #CFS last year. I thought I'd highlight it on an existing thread on James Baraniuk's work:




    Pdf: http://www.regulations.gov/api/cont...29ca75&disposition=attachment&contentType=pdf
     
  9. osisposis

    osisposis Senior Member

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    Glob J Health Sci. 2012 Dec 12;5(2):94-110. doi: 10.5539/gjhs.v5n2p94.
    .Dyspnea in Chronic Fatigue Syndrome (CFS): comparison of two prospective cross-sectional studies
    Ravindran M1, Adewuyi O, Zheng Y, Rayhan RU, Le U, Timbol C, Merck S, Esteitie R, Read C, Cooney M, Baraniuk J.

    Author information

    Abstract
    Chronic Fatigue Syndrome (CFS) subjects have many systemic complaints including shortness of breath. Dyspnea was compared in two CFS and control cohorts to characterize pathophysiology. Cohort 1 of 257 CFS and 456 control subjects were compared using the Medical Research Council chronic Dyspnea Scale (MRC Score; range 0-5). Cohort 2 of 106 CFS and 90 controls answered a Dyspnea Severity Score (range 0-20) adapted from the MRC Score. Subsets of both cohorts completed CFS Severity Scores, fatigue, and other questionnaires. A subset had pulmonary function and total lung capacity measurements. Results show MRC Scores were equivalent between sexes in Cohort 1 CFS (1.92 [1.72-2.16]; mean [95% C.I.]) and controls (0.31 [0.23-0.39]; p<0.0001). Receiver-operator curves identified 2 as the threshold for positive MRC Scores in Cohort 1. This indicated 54% of CFS, but only 3% of controls, had significant dyspnea. In Cohort 2, Dyspnea Score threshold of 4 indicated shortness of breath in 67% of CFS and 23% of controls. Cohort 2 Dyspnea Scores were higher for CFS (7.80 [6.60-9.00]) than controls (2.40 [1.60-3.20]; p<0.0001). CFS had significantly worse fatigue and other complaints compared to controls. Pulmonary function was normal in CFS, but Borg scores and sensations of chest pain and dizziness were significantly greater during testing than controls. General linear model of Cohort 2 CFS responses linked Dyspnea with rapid heart rate, chest pain and dizziness. In conclusion, sensory hypersensitivity without airflow limitation contributed to dyspnea in CFS. Correlates of dyspnea in controls were distinct from CFS suggesting different mechanisms.
    http://www.ncbi.nlm.nih.gov/pubmed/23445698
     
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  10. Never Give Up

    Never Give Up Collecting improvements, until there's a cure.

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    Sounds to me like POTS is causing the Dyspnea, not sensory hypersensitivity.
     
  11. WillowJ

    WillowJ Senior Member

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  12. Kina

    Kina Moderation Team Lead

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  13. osisposis

    osisposis Senior Member

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    osisposis Senior Member

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