Abstract
BackgroundThere are no known objective biomarkers to assist with the diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). A small number of studies have shown that ME/CFS patients exhibit an earlier onset of ventilatory threshold (VT) on the second of two cardiopulmonary exercise tests (CPET) performed on consecutive days. However, cut-off values which could be used to differentiate between ME/CFS patients have not been established.Methods16 ME/CFS patients and 10 healthy controls underwent CPET on a cycle-ergometer on 2-consecutive days. Heart rate (HR), ventilation, ratings of perceived exertion (RPE) and work rate (WR) were assessed on both days.ResultsWR at VT decreased from day 1 to day 2 and by a greater magnitude in ME/CFS patients (p < 0.01 group × time interaction). No interaction effects were found for any other parameters. ROC curve analysis of the percentage change in WR at VT revealed decreases of − 6.3% to − 9.8% provided optimal sensitivity and specificity respectively for distinguishing between patients with ME/CFS and controls.ConclusionThe decrease in WR at VT of 6.3–9.8% on the 2nd day of consecutive-day CPET may represent an objective biomarker that can be used to assist with the diagnosis of ME/CFS.
Highlights
There are no known objective biomarkers to assist with the diagnosis of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS)
All participants were required to be between the ages of 18–65 years, and ME/CFS patients had to have been previously diagnosed with ME/CFS based on one of three widely accepted diagnostic criteria: (1) 1994 Centers For Disease Control and Prevention (CDC 1994— known as the ‘Fukuda’ criteria [1]), (2) 2003 ‘Canadian’ Consensus Criteria (CCC) [3], or (3) 2011 International Consensus Criteria (ICC) [7]
With the exception of the patients being diagnosed with ME/CFS, all participants had to self-report as free of additional health conditions and injuries, and were required to be classed as lowmoderate risk based on a self-report pre-exercise health screening [16] — all self-report screenings were conducted in the presence of an Accredited Exercise Physiologist, and any potential participants who were classified as moderate risk based on this screening process underwent additional screening to ensure that participation in the study represented minimal risk to the participant
Summary
There are no known objective biomarkers to assist with the diagnosis of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS). The fatigue must be accompanied by four or more of the following symptoms: impaired short term memory or concentration; sore throat; tender cervical or axillary lymph nodes; muscle pain; multi-joint pain without arthritis; headaches of a new type, pattern, or severity; unrefreshing sleep; and post-exertional malaise lasting more than 24 h [1]. This clinical criteria was followed by the 2003 ‘Canadian Consensus Criteria’ [3] which required patients to meet the criteria for fatigue, post exertional malaise and/or fatigue, sleep dysfunction and pain, together with two or more neurological/cognitive manifestations and one or more symptoms from two of the categories of autonomic, neuroendocrine and immune manifestations, with the illness required to have persisted for at least 6 months [3]. The most recent widely used clinical criteria is the 2011 ‘International Consensus Criteria’ [7], which requires a number of pathological neurological impairments, immune/gastrointestinal/genitourinary impairments, and energy metabolism/ion transport impairments, with an increased focus on the requirement for patients to demonstrate post-exertional malaise as a key feature of the condition [7] in an attempt to better differentiate ME/CFS from other similar conditions (e.g. fibromyalgia)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
