Peak Oxygen Uptake in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Meta-Analysis

Abstract

To evaluate the magnitude of the difference in VO2peak between patients with Chronic Fatigue Syndrome/ Myalgic Encephalomyelitis (CFS/ME) and apparently healthy controls, 7 databases (Cochrane, PubMed, PsycINFO, Web of Knowledge, Embase, Scopus, Medline) were searched for articles published up to March 2018. Search terms included “chronic fatigue syndrom*”AND (“peak” OR “maxim*” OR “max”) AND (“oxygen uptake” OR “oxygen consumption” OR “VO2peak” or “VO2max”. Eligibility criteria were adults>18 y with clinically diagnosed CFS/ME, with VO2peak measured in a maximal test and compared against an apparently healthy control group. The methodological quality of included studies was assessed using a modified Systematic Appraisal of Quality for Observational Research critical appraisal framework. A random effects meta-analysis was conducted on 32 cross-sectional studies (effects). Pooled mean VO2peak was 5.2 (95% CI: 3.8–6.6) ml.kg−1min−1 lower in CFS/ME patients vs. healthy controls. Between-study variability (Tau) was 3.4 (1.5–4.5) ml.kg−1min−1 indicating substantial heterogeneity. The 95% prediction interval was −1.9 to 12.2 ml.kg−1min−1. The probability that the effect in a future study would be>the minimum clinically important difference of 1.1 ml.kg−1min−1 (in favour of controls) was 0.88 – likely to be clinically relevant. Synthesis of the available evidence indicates that CFS/ME patients have a substantially reduced VO2peak compared to controls.

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

“…Phys F: Physical Functioning scale of the SF-36 questionnaire; %peak VO 2 : peak VO 2 oxygen uptake relative to controls [37]; No of steps: number of steps per day functioning scale of 0.91 [44], suggesting that the use of the physical functioning score is valid with an acceptable sensitivity and specificity. Several studies have shown a decreased peak VO 2 in ME/CFS patients [45]. However, only one study determined the relation between the peak VO 2 and accelerometer data in female ME/CFS patients: higher peak VO 2 values were related to a higher physical activity time, physical activity energy expenditure, and a mean energy expenditure [46].…”

The physiological time line of post‐exertional malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

“…Current research shows disparity when comparing individuals with ME/CFS to those who are healthy controls, with some indicating that healthy controls have a higher peak VO 2 compared to those with ME/CFS and others whom indicate that those with ME/CFS have a peak VO 2, which is similar to those who are healthy controls . In spite of this, a recent meta‐analysis compared the data of healthy controls and those with ME/CFS from a single exercise test. Franklin et al demonstrated a pooled mean VO 2 peak that was 5.2 mL kg −1 min −1 lower in ME/CFS compared with healthy controls .…”

“…In spite of this, a recent meta‐analysis compared the data of healthy controls and those with ME/CFS from a single exercise test. Franklin et al demonstrated a pooled mean VO 2 peak that was 5.2 mL kg −1 min −1 lower in ME/CFS compared with healthy controls . However, between subject variability was 3.5 (1.5‐4.5 mL kg −1 min −1 ) indicating substantial heterogeneity.…”

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

“…Several studies have shown a decreased peak VO 2 in ME/CFS patients [46]. However, only one study determined the relation between the peak VO 2 and accelerometer data in female ME/CFS patients: higher peak VO 2 values were related to a higher physical activity time, physical activity energy expenditure, and a mean energy expenditure [47].…”