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Nature Communications Jan 2024A subgroup of patients infected with SARS-CoV-2 remain symptomatic over three months after infection. A distinctive symptom of patients with long COVID is...
A subgroup of patients infected with SARS-CoV-2 remain symptomatic over three months after infection. A distinctive symptom of patients with long COVID is post-exertional malaise, which is associated with a worsening of fatigue- and pain-related symptoms after acute mental or physical exercise, but its underlying pathophysiology is unclear. With this longitudinal case-control study (NCT05225688), we provide new insights into the pathophysiology of post-exertional malaise in patients with long COVID. We show that skeletal muscle structure is associated with a lower exercise capacity in patients, and local and systemic metabolic disturbances, severe exercise-induced myopathy and tissue infiltration of amyloid-containing deposits in skeletal muscles of patients with long COVID worsen after induction of post-exertional malaise. This study highlights novel pathways that help to understand the pathophysiology of post-exertional malaise in patients suffering from long COVID and other post-infectious diseases.
Topics: Humans; Post-Acute COVID-19 Syndrome; SARS-CoV-2; Case-Control Studies; COVID-19; Fatigue; Musculoskeletal Abnormalities; Muscle, Skeletal; Pain; Plaque, Amyloid
PubMed: 38177128
DOI: 10.1038/s41467-023-44432-3 -
Nutrition Journal Jul 2023Resistance training adaptively increases muscle strength and mass, contributing to athletic performance and health promotion. Dietary intervention with natural foods... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Resistance training adaptively increases muscle strength and mass, contributing to athletic performance and health promotion. Dietary intervention with natural foods provides nutrients that help accelerate muscle adaptation to training. Matcha green tea contains several bioactive factors such as antioxidants, amino acids, and dietary fibers; however, its effect on muscle adaptation is unclear. In this study, we aimed to investigate the effects of matcha beverage intake on muscle adaptation to resistance training.
METHODS
Healthy, untrained men were randomized into placebo and matcha groups. Participants consumed either a matcha beverage containing 1.5 g of matcha green tea powder or a placebo beverage twice a day and engaged in resistance training programs for 8 (trial 1) or 12 weeks (trial 2).
RESULTS
In trial 1, maximum leg strength after training tended to increase more in the matcha group than that in the placebo group. In the matcha group, subjective fatigue after exercise at 1 week of training was lower than that in the placebo group. Gut microbe analysis showed that the abundance of five genera changed after matcha intake. The change in Ruminococcus, Butyricimonas, and Oscillospira compositions positively correlated with the change in maximum strength. In trial 2, the change in skeletal muscle mass in response to training was larger in the matcha group. In addition, the salivary cortisol level was lower in the matcha group than that in the placebo group.
CONCLUSION
Daily intake of matcha green tea beverages may help in muscle adaptation to training, with modulations in stress and fatigue responses and microbiota composition.
Topics: Male; Humans; Antioxidants; Resistance Training; Tea; Muscle Strength; Exercise; Muscle, Skeletal
PubMed: 37403052
DOI: 10.1186/s12937-023-00859-4 -
Proceedings of the National Academy of... Aug 2023Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence...
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence of a specific cause, making its clinical management challenging. A better understanding of the molecular mechanism underlying this apparent bioenergetic deficiency state may reveal insights for developing targeted treatment strategies. We report that overexpression of (), here identified in a 38-y-old woman suffering from long-standing fatigue and exercise intolerance, can disrupt mitochondrial respiratory supercomplex formation and is associated with endoplasmic reticulum (ER) stress. Increased expression of in transgenic mice markedly decreased their treadmill running capacity with concomitantly impaired respiratory supercomplex assembly and reduced complex IV levels in skeletal muscle mitochondria. WASF3 induction by ER stress using endotoxin, well known to be associated with fatigue in humans, also decreased skeletal muscle complex IV levels in mice, while decreasing WASF3 levels by pharmacologic inhibition of ER stress improved mitochondrial function in the cells of the patient with chronic fatigue. Expanding on our findings, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels and aberrant ER stress activation. In addition to revealing a potential mechanism for the bioenergetic deficiency in ME/CFS, our study may also provide insights into other disorders associated with fatigue such as rheumatic diseases and long COVID.
Topics: Animals; Female; Humans; Mice; COVID-19; Fatigue Syndrome, Chronic; Mitochondria; Post-Acute COVID-19 Syndrome; Respiration; Wiskott-Aldrich Syndrome Protein Family; Mice, Transgenic
PubMed: 37579159
DOI: 10.1073/pnas.2302738120 -
Australian Critical Care : Official... Jul 2023In patients who are ventilator-dependent in the intensive care unit, inspiratory muscle training may improve inspiratory muscle strength and accelerate liberation from... (Randomized Controlled Trial)
Randomized Controlled Trial
Does mechanical threshold inspiratory muscle training promote recovery and improve outcomes in patients who are ventilator-dependent in the intensive care unit? The IMPROVE randomised trial.
BACKGROUND
In patients who are ventilator-dependent in the intensive care unit, inspiratory muscle training may improve inspiratory muscle strength and accelerate liberation from the ventilator, but optimal training parameters are yet to be established, and little is known about the impact of inspiratory muscle training on quality of life or dyspnoea. Thus, we sought to ascertain whether inspiratory muscle training, commenced while ventilator-dependent, would improve outcomes for patients invasively ventilated for 7 days or longer.
METHODS
In this randomised trial with assessor blinding and intention-to-treat analysis, 70 participants (mechanically ventilated ≥7 days) were randomised to receive once-daily supervised high-intensity inspiratory muscle training with a mechanical threshold device in addition to usual care or to receive usual care (control). Primary outcomes were inspiratory muscle strength (maximum inspiratory pressure % predicted) and endurance (fatigue resistance index) at ventilator liberation and 1 week later. Secondary outcomes included quality of life (SF-36v2, EQ-5D), dyspnoea, physical function, duration of ventilation, and in-hospital mortality.
RESULTS
Thirty-three participants were randomly allocated to the training group, and 37 to the control group. There were no statistically significant differences in strength (maximum inspiratory pressure) (95% confidence interval [CI]: -7.4 to 14.0) or endurance (fatigue resistance index) (95% CI: -0.003 to 0.436). Quality of life improved significantly more in the training group than in the control group (EQ-5D: 17.2; 95% CI: 1.3-33.0) (SF-36-PCS: 6.97; 95% CI: 1.96-12.00). Only the training group demonstrated significant reductions in dyspnoea (-1.5 at rest, -1.9 during exercise). There were no between-group differences in duration of ventilation or other measures. In-hospital mortality was higher in the control group than in the training group (9 vs 4, 24% vs 12%, p = 0.23).
CONCLUSIONS
In patients who are ventilator-dependent, mechanical threshold loading inspiratory muscle training improves quality of life and dyspnoea, even in the absence of strength improvements or acceleration of ventilator liberation.
Topics: Humans; Respiration, Artificial; Ventilator Weaning; Breathing Exercises; Quality of Life; Respiratory Muscles; Intensive Care Units; Ventilators, Mechanical; Dyspnea
PubMed: 36041982
DOI: 10.1016/j.aucc.2022.07.002