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Keller:

(minstens) vier subgroepen

op basis van de

dubbele inspanningstest

 

 

 

 


 

 

 

Volgens een presentatie van Betsy Keller op de recente IACFS-ME conferentie

kunnen we CVS-patiŽnten op basis van de dubbele fietstest in vier groepen indelen:

  1. patiŽnten waarvan de maximale zuurstofopname de tweede dag beduidend lager is (34%) en/of
  2. patiŽnten waarvan de zuurstofopname bij de verzuringsdrempel sterk afneemt (39%) en/of,
  3. patiŽnten die op een andere wijze abnormaal reageren op de dubbele fietstest, en
  4. patiŽnten die bij de tweede inspaningstest vergelijkbaar presteren/niet achteruit gaan (29%)

De vierde groep zou nader onderzocht moeten worden,

wellicht omdat deze CVS-patiŽnten wel normaal reageren op 'revalidatieprogramma's'.

 

 


 

Subsets of ME/CFS patient responses to a 2-day CPET

IACFS/ME Conference, 2016 October 27-30. Fort Lauderdale, Florida.

Betsy Keller.

 

Betsy Keller,

Professor,

Department of Exercise and Sport Sciences,

Ithaca College,

318 Center for Health Sciences,

Ithaca,

NY 14850

 

 

Background:

 

Studies to assess the efficacy of a two-day cardiopulmonary exercise test (2-d CPET) protocol

to identify post-exertion malaise (PEM) in ME/CFS

first revealed that ME/CFS patients often fail to reproduce peak VO2 (VO2peak) during test 2

due to PEM provoked with test 1.

 

Subsequent research indicated that a subset of patients

failed to reproduce VO2 at ventilatory/anaerobic threshold (VAT),

but did reproduce VO2peak,

suggesting that responses to exertion may distinguish subsets of patients.

 

Identifying subsets of ME/CFS patient responses to exertion

would enable us to further explore other potential correlates,

such as metabolic markers or bacterial microbiome of the gut.

 

 

Objectives:

 

To classify the responses of ME/CFS patients to a 2-d CPET protocol

to determine if ME/CFS patients demonstrate subsets of responses

in addition to failure to reproduce VO2peak or VO2@VAT.

 

 

Methods:

 

Responses to a 2-d CPET protocol were evaluated for 94 ME/CFS patients.

 

Patient responses were evaluated based on failure to reproduce VO2peak or VO2@VAT,

as well as failure to respond normally with regard to

autonomic parameters (heart rate, blood pressure), ventilatory parameters,

as well as cases that reproduced CPETs within normal variation.

 

 

Results:

 

Of 97 cases,

34% comprised a subset of responders that failed to reproduce VO2peak, and

39% failed to reproduce VO2@VAT within normal variation.

 

Additionally, subsets were also described by

autonomic anomalies (43%), ventilatory anomalies (47%), and

normal reproduction of CPETs (29%).

 

Membership in more than one subset by several cases explained

the sum total of all subsets greater than 100%.

 

 

Conclusion:

 

Assessment of PEM using the 2-d CPET protocol

should consider abnormal responses to exertion that extend

beyond VO2peak or VO2@VAT and

consider disruption of autonomic and ventilatory responses

as indicators of inappropriate recovery, or PEM, following exertion.

 

Additionally, patients diagnosed with ME/CFS

who reproduce the 2-day CPET within normal parameters

may describe a unique subset that requires further study.

 

Preliminary data will be discussed

which indicates that this subset may correspond with other prognostic indicators.

 

 

http://iacfsme.org/ME-CFS-Primer-Education/News/IACFSME-2016-Program.aspx