Comparison of the muscle oxygenation during submaximal and maximal exercise tests in patients post-coronavirus disease 2019 syndrome with pulmonary involvement

Abstract:

Introduction: Pulmonary involvement is prevalent in patients with coronavirus disease 2019 (COVID-19). Arterial hypoxemia may reduce oxygen transferred to the skeletal muscles, possibly leading to impaired exercise capacity. Oxygen uptake may vary depending on the increased oxygen demand of the muscles during submaximal and maximal exercise.

Objective: This study aimed to compare muscle oxygenation during submaximal and maximal exercise tests in patients with post-COVID-19 syndrome with pulmonary involvement.

Methods: Thirty-nine patients were included. Pulmonary function (spirometry), peripheral muscle strength (dynamometer), quadriceps femoris (QF) muscle oxygenation (Moxy® device), and submaximal exercise capacity (six-minute walk test (6-MWT)) were tested on the first day, maximal exercise capacity (cardiopulmonary exercise test (CPET)) was tested on the second day. Physical activity level was evaluated using an activity monitor worn for five consecutive days. Cardiopulmonary responses and muscle oxygenation were compared during 6-MWT and CPET.

Results: Patients’ minimum and recovery muscle oxygen saturation were significantly decreased; maximum total hemoglobin increased, heart rate, blood pressure, breathing frequency, dyspnea, fatigue, and leg fatigue at the end-of-test and recovery increased in CPET compared to 6-MWT (p < .050). Peak oxygen consumption (VO2peak) was 18.15 ± 4.75 ml/min/kg, VO2peak; percent predicted < 80% was measured in 51.28% patients. Six-MWT distance and QF muscle strength were less than 80% predicted in 58.9% and 76.9% patients, respectively.

Conclusions: In patients with post-COVID-19 syndrome with pulmonary involvement, muscle deoxygenation of QF is greater during maximal exercise than during submaximal exercise. Specifically, patients with lung impairment should be evaluated for deoxygenation and should be taken into consideration during pulmonary rehabilitation.

Source: Kavalcı Kol B, Boşnak Güçlü M, Baytok E, Yılmaz Demirci N. Comparison of the muscle oxygenation during submaximal and maximal exercise tests in patients post-coronavirus disease 2019 syndrome with pulmonary involvement. Physiother Theory Pract. 2024 Mar 12:1-14. doi: 10.1080/09593985.2024.2327534. Epub ahead of print. PMID: 38469863. https://pubmed.ncbi.nlm.nih.gov/38469863/

Health outcomes for Long COVID are comparable with ME/CFS

Press Release: Griffith News

People with Long COVID in Australia have poor health outcomes that are comparable with another emerging disease known as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), new Griffith University research has discovered.

PhD student Breanna Weigel from Griffith’s National Centre for Neuroimmunology and Emerging Diseases (NCNED) will be presenting the findings in Singapore this month at the International Public Health Conference.

Ms Weigel said the study found people with Long COVID have the same health outcomes as ME/CFS over a 12-month period.

“Quality of life and disability scores were significantly poorer for both Long COVID and ME/CFS when compared with healthy people,” she said.

“However, there were no differences between ME/CFS and Long COVID groups which indicates considerable reductions in functional capacity and health and well-being among people living with these illnesses.”

The research found only a few differences in more than 25 different symptoms between Long COVID and ME/CFS participants.

Importantly, both ME/CFS and Long COVID groups had comparable prevalence with the severity of their illness.

Both groups over time had the same symptom presentation of significantly impaired cognition, mobility, bodily pain, and post-exertional malaise (PEM) which means symptoms get worse after physical or mental activity.

PEM is very disabling and causes changes in symptoms and a further reduction in ability to do everyday activities.

Director of the NCNED, Professor Sonya Marshall-Gradisnik, said: “This research highlighted the continued impact of Long COVID on peoples’ lives, which is especially poignant as today we recognise International Long COVID Awareness Day.”

“The research forms one of many Long COVID investigations and clinical trials being undertaken at the national centre where it is hoped these findings will provide pathways for those with Long COVID.

“We are uniquely positioned nationally as we are the only centre to undertake scientific laboratory and MRI research in Long COVID and ME/CFS in tandem, and monitor the health and economic impact of the patients.

“At the national centre we also undertake clinical trials and contribute to best practice guidelines such as the recently published guidelines in the British Medical Journal for ME.”

Dr Natalie Eaton-Fitch, who was an undergraduate student at Griffith University and is now an emerging researcher at the NCNED said: “Researchers are very fortunate to have wonderful opportunities at all stages of their careers and to know research can make a real-world difference for people.”

Ms Weigel’s work builds upon the Issues Brief she did in collaboration with the Deeble Institute that reported how patient experiences can guide the development of Long COVID health policy.

 

Impaired Sleep in Patients with Post-COVID-19 Syndrome Compared to Healthy Controls: A Cross-Sectional Trial

Abstract:

Introduction: To objectify self-reported sleep disorders in individuals with post-COVID-syndrome (PCS), we aimed to investigate the prevalence and nature of sleep disturbances by polysomnography (PSG) in PCS compared to healthy individuals.

Methods: People with PCS (n = 21) and healthy controls (CON, n = 10) were included in this prospective trial. At baseline, clinical and social anamnesis, lung function, 1 min sit-to-stand test (STST) and Pittsburgh Sleep Quality Index (PSQI) were assessed. For a single-night, sleep health was evaluated by video-PSG. The apnoea/hypopnea index (AHI) was used as the primary outcome.

Results: Twenty patients with PCS (50 ± 11 y, BMI 27.1 m2/kg, SARS-CoV-2 infection 8.5 ± 4.5 months ago) and 10 CON participants (46 ± 10 y, BMI 23.0 m2/kg, no SARS-CoV-2 infection in the history) completed the study. Forced vital capacity (p = 0.018), STST repetitions (p &lt; 0.001), and symptoms of dyspnoea (at rest: p = 0.002, exertion: p &lt; 0.001) were worse in PCS compared to CON. PSQI score (PCS: 7.5 ± 4.7 points) was higher in PCS compared to CON (Δ = 3.7 points, 95% CI [0.4-7.1] p = 0.015), indicating poor sleep in 80% of patients with PCS. Although PSG showed comparable sleep stage distributions in both groups, AHI (Δ = 9.0 n/h, 95% CI [3.3-14.8], p = 0.002), PLM index (Δ = 5.1 n/h, 95% CI [0.4-9.8], p = 0.017), and the prevalence of sleep apnoea (60% vs. 10%, p = 0.028) was significantly higher in PCS compared to CON.

Conclusion: Quantifiable subjective limitations of sleep have been revealed by PSG data in this PCS cohort. More than half of PCS patients had signs of sleep apnoea, highlighting the importance of sleep screening in PCS.

Source: Jarosch I, Schneeberger T, Stegemann A, Gloeckl R, Leitl D, Dennis C, Hitzl W, Schoen C, Koczulla AR. Impaired Sleep in Patients with Post-COVID-19 Syndrome Compared to Healthy Controls: A Cross-Sectional Trial. Respiration. 2024 Mar 1:1-5. doi: 10.1159/000536272. Epub ahead of print. PMID: 38432219. https://karger.com/res/article/doi/10.1159/000536272/896169/Impaired-Sleep-in-Patients-with-Post-COVID-19 (Full text)

Iron dysregulation and inflammatory stress erythropoiesis associates with long-term outcome of COVID-19

Abstract:

Persistent symptoms following SARS-CoV-2 infection are increasingly reported, although the drivers of post-acute sequelae (PASC) of COVID-19 are unclear. Here we assessed 214 individuals infected with SARS-CoV-2, with varying disease severity, for one year from COVID-19 symptom onset to determine the early correlates of PASC.

A multivariate signature detected beyond two weeks of disease, encompassing unresolving inflammation, anemia, low serum iron, altered iron-homeostasis gene expression and emerging stress erythropoiesis; differentiated those who reported PASC months later, irrespective of COVID-19 severity. A whole-blood heme-metabolism signature, enriched in hospitalized patients at month 1-3 post onset, coincided with pronounced iron-deficient reticulocytosis. Lymphopenia and low numbers of dendritic cells persisted in those with PASC, and single-cell analysis reported iron maldistribution, suggesting monocyte iron loading and increased iron demand in proliferating lymphocytes.

Thus, defects in iron homeostasis, dysregulated erythropoiesis and immune dysfunction due to COVID-19 possibly contribute to inefficient oxygen transport, inflammatory disequilibrium and persisting symptomatology, and may be therapeutically tractable.

Source: Hanson AL, Mulè MP, Ruffieux H, Mescia F, Bergamaschi L, Pelly VS, Turner L, Kotagiri P; Cambridge Institute of Therapeutic Immunology and Infectious Disease–National Institute for Health Research (CITIID–NIHR) COVID BioResource Collaboration; Göttgens B, Hess C, Gleadall N, Bradley JR, Nathan JA, Lyons PA, Drakesmith H, Smith KGC. Iron dysregulation and inflammatory stress erythropoiesis associates with long-term outcome of COVID-19. Nat Immunol. 2024 Mar;25(3):471-482. doi: 10.1038/s41590-024-01754-8. Epub 2024 Mar 1. PMID: 38429458; PMCID: PMC10907301. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10907301/ (Full text)

Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment

Abstract:

Vascular disruption has been implicated in coronavirus disease 2019 (COVID-19) pathogenesis and may predispose to the neurological sequelae associated with long COVID, yet it is unclear how blood–brain barrier (BBB) function is affected in these conditions. Here we show that BBB disruption is evident during acute infection and in patients with long COVID with cognitive impairment, commonly referred to as brain fog.

Using dynamic contrast-enhanced magnetic resonance imaging, we show BBB disruption in patients with long COVID-associated brain fog. Transcriptomic analysis of peripheral blood mononuclear cells revealed dysregulation of the coagulation system and a dampened adaptive immune response in individuals with brain fog.

Accordingly, peripheral blood mononuclear cells showed increased adhesion to human brain endothelial cells in vitro, while exposure of brain endothelial cells to serum from patients with long COVID induced expression of inflammatory markers.

Together, our data suggest that sustained systemic inflammation and persistent localized BBB dysfunction is a key feature of long COVID-associated brain fog.

Source: Greene C, Connolly R, Brennan D, Laffan A, O’Keeffe E, Zaporojan L, O’Callaghan J, Thomson B, Connolly E, Argue R, Martin-Loeches I, Long A, Cheallaigh CN, Conlon N, Doherty CP, Campbell M. Blood-brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment. Nat Neurosci. 2024 Mar;27(3):421-432. doi: 10.1038/s41593-024-01576-9. Epub 2024 Feb 22. PMID: 38388736; PMCID: PMC10917679. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10917679/ (Full text)

What is the impact of long-term COVID-19 on workers in healthcare settings? A rapid systematic review of current evidence

Abstract:

Background: Long COVID is a devastating, long-term, debilitating illness which disproportionately affects healthcare workers, due to the nature of their work. There is currently limited evidence specific to healthcare workers about the experience of living with Long COVID, or its prevalence, pattern of recovery or impact on healthcare.

Objective: Our objective was to assess the effects of Long COVID among healthcare workers and its impact on health status, working lives, personal circumstances, and use of health service resources.

Methods: We conducted a systematic rapid review according to current methodological standards and reported it in adherence to the PRISMA 2020 and ENTREQ statements.

Results: We searched relevant electronic databases and identified 3770 articles of which two studies providing qualitative evidence and 28 survey studies providing quantitative evidence were eligible. Thematic analysis of the two qualitative studies identified five themes: uncertainty about symptoms, difficulty accessing services, importance of being listened to and supported, patient versus professional identity and suggestions to improve communication and services for people with Long COVID. Common long-term symptoms in the survey studies included fatigue, headache, loss of taste and/or smell, breathlessness, dyspnoea, difficulty concentrating, depression and anxiety.

Conclusion: Healthcare workers struggled with their dual identity (patient/doctor) and felt dismissed or not taken seriously by their doctors. Our findings are in line with those in the literature showing that there are barriers to healthcare professionals accessing healthcare and highlighting the challenges of receiving care due to their professional role. A more representative approach in Long COVID research is needed to reflect the diverse nature of healthcare staff and their occupations. This rapid review was conducted using robust methods with the codicil that the pace of research into Long COVID may mean relevant evidence was not identified.

Source: Cruickshank M, Brazzelli M, Manson P, Torrance N, Grant A. What is the impact of long-term COVID-19 on workers in healthcare settings? A rapid systematic review of current evidence. PLoS One. 2024 Mar 5;19(3):e0299743. doi: 10.1371/journal.pone.0299743. PMID: 38442116; PMCID: PMC10914278. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10914278/ (Full text)

Possible Role of Fibrinaloid Microclots in Postural Orthostatic Tachycardia Syndrome (POTS): Focus on Long COVID

Abstract:

Postural orthostatic tachycardia syndrome (POTS) is a common accompaniment of a variety of chronic, inflammatory diseases, including long COVID, as are small, insoluble, ‘fibrinaloid’ microclots.
We here develop the argument, with accompanying evidence, that fibrinaloid microclots, through their ability to block the flow of blood through microcapillaries and thus cause tissue hypoxia, are not simply correlated with but in fact, by preceding it, may be a chief intermediary cause of POTS, in which tachycardia is simply the body’s exaggerated ‘physiological’ response to hypoxia. Similar reasoning accounts for the symptoms bundled under the term ‘fatigue’.
Amyloids are known to be membrane disruptors, and when their targets are nerve membranes, this can explain neurotoxicity and hence the autonomic nervous system dysfunction that contributes to POTS. Taken together as a system view, we indicate that fibrinaloid microclots can serve to link POTS and fatigue in long COVID in a manner that is at once both mechanistic and explanatory. This has clear implications for the treatment of such diseases.
Source: Kell DB, Khan MA, Kane B, Lip GYH, Pretorius E. Possible Role of Fibrinaloid Microclots in Postural Orthostatic Tachycardia Syndrome (POTS): Focus on Long COVID. Journal of Personalized Medicine. 2024; 14(2):170. https://doi.org/10.3390/jpm14020170 https://www.mdpi.com/2075-4426/14/2/170 (Full text)

Unravelling shared mechanisms: insights from recent ME/CFS research to illuminate long COVID pathologies

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic illness often triggered by an initiating acute event, mainly viral infections. The transition from acute to chronic disease remains unknown, but interest in this phenomenon has escalated since the COVID-19 pandemic and the post-COVID-19 illness, termed ‘long COVID’ (LC). Both ME/CFS and LC share many clinical similarities.

Here, we present recent findings in ME/CFS research focussing on proposed disease pathologies shared with LC. Understanding these disease pathologies and how they influence each other is key to developing effective therapeutics and diagnostic tests. Given that ME/CFS typically has a longer disease duration compared with LC, with symptoms and pathologies evolving over time, ME/CFS may provide insights into the future progression of LC.

Source: Annesley SJ, Missailidis D, Heng B, Josev EK, Armstrong CW. Unravelling shared mechanisms: insights from recent ME/CFS research to illuminate long COVID pathologies. Trends Mol Med. 2024 Mar 4:S1471-4914(24)00028-5. doi: 10.1016/j.molmed.2024.02.003. Epub ahead of print. PMID: 38443223. https://www.sciencedirect.com/science/article/pii/S1471491424000285 (Full text)

Ebbing Strength, Fading Power: Unveiling the Impact of Persistent Fatigue on Muscle Performance in COVID-19 Survivors

Abstract:

The total number of confirmed cases of COVID-19 caused by SARS-CoV-2 virus infection is over 621 million. Post-COVID-19 syndrome, also known as long COVID or long-haul COVID, refers to a persistent condition where individuals experience symptoms and health issues after the acute phase of COVID-19.

The aim of this study was to assess the strength and fatigue of skeletal muscles in people recovered from COVID-19. A total of 94 individuals took part in this cross-sectional study, with 45 participants (referred to as the Post-COVID Cohort, PCC) and 49 healthy age-matched volunteers (Healthy Control Cohort, HCC).

This research article uses the direct dynamometry method to provide a detailed analysis of post-COVID survivors’ strength and power characteristics. The Biodex System 4 Pro was utilized to evaluate muscle strength characteristics during the fatigue test. The fatigue work in extensors and flexors was significantly higher in the PCC.  The PCC also showed significantly less power in both extensors and flexors compared to the HCC.

In conclusion, this study provides compelling evidence of the impact of post-COVID-19 fatigue on muscle performance, highlighting the importance of considering these effects in the rehabilitation and care of individuals recovering from the virus. PCC achieved lower muscle strength values than HCC.

Source: Kowal M, Morgiel E, Winiarski S, Dymarek R, Bajer W, Madej M, Sebastian A, Madziarski M, Wedel N, Proc K, Madziarska K, Wiland P, Paprocka-Borowicz M. Ebbing Strength, Fading Power: Unveiling the Impact of Persistent Fatigue on Muscle Performance in COVID-19 Survivors. Sensors (Basel). 2024 Feb 15;24(4):1250. doi: 10.3390/s24041250. PMID: 38400407; PMCID: PMC10892381. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10892381/ (Full text)

Sex differences in symptomatology and immune profiles of Long COVID

Abstract:

Strong sex differences in the frequencies and manifestations of Long COVID (LC) have been reported with females significantly more likely than males to present with LC after acute SARS-CoV-2 infection1-7. However, whether immunological traits underlying LC differ between sexes, and whether such differences explain the differential manifestations of LC symptomology is currently unknown.

Here, we performed sex-based multi-dimensional immune-endocrine profiling of 165 individuals8 with and without LC in an exploratory, cross-sectional study to identify key immunological traits underlying biological sex differences in LC.

We found that female and male participants with LC experienced different sets of symptoms, and distinct patterns of organ system involvement, with female participants suffering from a higher symptom burden. Machine learning approaches identified differential sets of immune features that characterized LC in females and males. Males with LC had decreased frequencies of monocyte and DC populations, elevated NK cells, and plasma cytokines including IL-8 and TGF-β-family members.

Females with LC had increased frequencies of exhausted T cells, cytokine-secreting T cells, higher antibody reactivity to latent herpes viruses including EBV, HSV-2, and CMV, and lower testosterone levels than their control female counterparts. Testosterone levels were significantly associated with lower symptom burden in LC participants over sex designation.

These findings suggest distinct immunological processes of LC in females and males and illuminate the crucial role of immune-endocrine dysregulation in sex-specific pathology.

Source: Julio Silva, Takehiro Takahashi, Jamie Wood, Peiwen Lu, Sasha Tabachnikova, Jeffrey Gehlhausen, Kerrie Greene, Bornali Bhattacharjee, Valter Silva Monteiro, Carolina Lucas, Rahul Dhodapkar, Laura Tabacof, Mario Pena-Hernandez, Kathy Kamath, Tianyang Mao, Dayna Mccarthy, Ruslan Medzhitov, David van Dijk, Harlan Krumholz, Leying Guan, David Putrino, Akiko Iwasaki. Sex differences in symptomatology and immune profiles of Long COVID. medRxiv 2024.02.29.24303568; doi: https://doi.org/10.1101/2024.02.29.24303568 https://www.medrxiv.org/content/10.1101/2024.02.29.24303568v1 (Full study available as PDF file)