Fibromyalgia and Chronic Fatigue Syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function...2022

Fibromyalgia and Chronic Fatigue Syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals

authors Zambolin et al

Abstract
Objective
To determine cardiorespiratory fitness and neuromuscular function of people with CFS and FMS compared to healthy individuals.

Design
Systematic review and meta-analysis.

Data sources
PubMed, Medline, CINAHL, AMED, Cochrane Central Register of Controlled Trials (CENTRAL), and PEDro from inception to June 2022.

Eligible criteria for selecting studies
Studies were included if presenting baseline data on cardiorespiratory fitness and/or neuromuscular function from observational or interventional studies of patients diagnosed with FMS or CFS. Participants were aged 18 years or older, with results also provided for healthy controls. Risk of bias assessment was conducted using the Quality Assessment Tool for Quantitative Studies (EPHPP).

Results
99 studies including 9853 participants (5808 patients; 4405 healthy controls) met our eligibility criteria. Random effects meta-analysis showed lower cardiorespiratory fitness (VO2max, anaerobic threshold, peak lactate) and neuromuscular function (MVC, fatigability, voluntary activation, muscle volume, muscle mass, rate of perceived exertion) in CFS and FMS compared to controls: all with moderate to high effect sizes.

Discussion
Our results demonstrate lower cardiorespiratory fitness and muscle function in those living with FMS or CFS when compared to controls. There were indications of dysregulated neuro-muscular interactions including heightened perceptions of effort, reduced ability to activate the available musculature during exercise and reduced tolerance of exercise.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0276009

 

I found this surprising:

Data from 11 studies showed that patients had significantly lower peak lactate values than controls (Z = 3.44, p = 0.00001), with a large effect size (SMD = -0.84, 95%CI = -1.33 to -0.36). Heterogeneity was classified as substantial (I2 = 80%).

Studies with low risk of bias included 82 patients and 81 healthy controls (I2 = 41%). They also showed lower peak lactate for patients, but with small effect size (Z = 1.50, p = 0.13; ES = -0.27; 95%CI = -0.62, 0.08).

 

and this:

Thirty-nine studies showed that patients had significantly lower peak HR than controls at the end of incremental exercise, even when normalized to age. There was a moderate-high effect size (SMD = -0.64, 95%CI = -0.77 to -0.50) and heterogeneity was classified as substantial (I2 = 58%).

Studies with low risk of bias included 1025 patients and 813 healthy controls (I2 = 26%). They also showed lower peak HR for patients, but with large effect size (SMD = -0.57; 95%CI = -0.70, -0.44).