Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

To assess biobehavioral sex differences in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) utilizing a low burden exercise protocol, 22 females and 15 males with ME/CFS and 14 healthy controls underwent two six-min walk tests.

Fifteen daily assessments were scheduled for fatigue and function ratings and heart monitoring. Six-min walk tests were conducted on days 8 and 9. The ME/CFS group showed high self-report fatigue and impaired physical function, whereas healthy controls did not show fatigue or function abnormalities.

In patients, no significant post-exercise changes were found for heart rate variability (HRV); however, heart rate decreased in ME/CFS males from Day 14 to Day 15 (p = 0.046). Female patients showed increased fatigue (p = 0.006) after the initial walk test, but a downward slope (p = 0.008) in fatigue following the second walk test. Male patients showed a decrease in self-report work limitation in the days after exercise (p = 0.046). The healthy control group evidenced a decrease in HRV after the walk tests from Day 9-14 (p = 0.038).

This pilot study did not confirm hypotheses that females as compared to males would show slower exercise recovery on autonomic or self-report (e.g. fatigue) measures. A more exertion-sensitive test may be required to document prolonged post-exertional abnormalities in ME/CFS.

Trial registration: NCT NCT03331419.

Source: Friedberg F, Adamowicz JL, Bruckenthal P, Milazzo M, Ramjan S, Zhang X, Yang J. Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome. Sci Rep. 2023 Apr 3;13(1):5442. doi: 10.1038/s41598-023-32581-w. PMID: 37012343. https://www.nature.com/articles/s41598-023-32581-w (Full text)

Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem illness characterized by substantial reduction in function accompanied by profound unexplained fatigue not significantly relieved by rest, post-exertional malaise, and other symptoms. Reduced natural killer (NK) cell count and cytotoxicity has been investigated as a biomarker for ME/CFS, but few clinical laboratories offer the test and multi-site verification studies have not been conducted.

Methods: We determined NK cell counts and cytotoxicity in 174 (65%) ME/CFS, 86 (32%) healthy control (HC) and 10 (3.7%) participants with other fatigue associated conditions (ill control [IC]) from the Multi-Site Clinical Assessment of ME/CFS (MCAM) study using an assay validated for samples shipped overnight instead of testing on day of venipuncture.

Results: We found a large variation in percent cytotoxicity [mean and (IQR) for ME/CFS and HC respectively, 34.1% (IQR 22.4-44.3%) and 33.6% (IQR 22.9-43.7%)] and no statistically significant differences between patients with ME/CFS and HC (p-value = 0.79). Analysis stratified on illness domain measured with standardized questionnaires did not identify an association of NK cytotoxicity with domain scores. Among all participants, NK cytotoxicity was not associated with survey results of physical and mental well-being, or health factors such as history of infection, obesity, smoking, and co-morbid conditions.

Conclusion: These results indicate this assay is not ready for clinical implementation and studies are needed to further explore immune parameters that may be involved in the pathophysiology of ME/CFS.

Source: Querec TD, Lin JS, Chen Y, Helton B, Kogelnik AM, Klimas NG, Peterson DL, Bateman L, Lapp C, Podell RN, Natelson BH, Unger ER; MCAM Study Group. Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study. J Transl Med. 2023 Apr 3;21(1):242. doi: 10.1186/s12967-023-03958-2. PMID: 37013608. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03958-2 (Full text)

Neurocognitive and psychiatric symptoms following infection with COVID-19: Evidence from laboratory and population studies

Abstract:

Objective: The objective of the current investigation was to examine associations between symptomatic COVID-19 history, neurocognitive function, and psychiatric symptoms using cognitive task performance, functional brain imaging, and a prospective population survey.

Methods: Study 1 was a laboratory study conducted between 3 May 2022 and 16 Nov 2022 involving 120 fully vaccinated community dwelling adults between 18 and 84 years of age (Mage = 31.96 (SD = 20.71), 63.3% female). In this cross-sectional study we examined the association between symptomatic COVID-19 infection history and performance on three computer tasks assessing cognitive function (Flanker interference, delay discounting and simple reaction time) and measured oxygen saturation within the prefrontal cortex using functional near infrared spectroscopy (fNIRS). Study 2 was a 2-wave population survey undertaken between 28 September 2021 and 21 March 2022, examining the prospective relationship between symptomatic COVID-19 and self-reported symptoms of cognitive dysfunction, depressive symptoms, anxiety symptoms, and agitation at 6-month follow up. The sample (N = 2,002, M age = 37.0, SD = 10.4; 60.8% female) was collected using a quota process to ensure equal numbers of vaccinated and unvaccinated individuals. Structural equation modelling with latent variables was performed on the population-level data, evaluating the fit of the proposed mediational model of symptomatic COVID-19 to psychiatric symptoms through cognitive dysfunction.

Results: Findings from Study 1 revealed significant effects of symptomatic COVID-19 history on Flanker interference and delay discounting. Effects on flanker performance were significantly stronger among older adult women (effect: 9.603, SE = 4.452, t = 2.157, p = .033), and were accompanied by task-related changes cerebral oxygenation at the right superior frontal gyrus (F (1, 143.1) = 4.729, p = .031). Additionally, those with a symptomatic COVID-19 infection history showed evidence of amplified delay discounting (coefficient = 0.4554, SE = 0.2208, t = 2.0629, p = .041). In Study 2, baseline symptomatic COVID-19 history was associated with self-reported cognitive dysfunction and a latent variable reflecting psychiatric symptoms of anxiety, depression and agitation at follow-up. Mediational analyses revealed evidence of cognitive mediation of clinically significant psychiatric outcomes: depression (indirect effect = 0.077, SE = 0.026, p = .003) and generalized anxiety (indirect effect = 0.060, SE = 0.021, p = .004).

Conclusions: Converging findings from laboratory and population survey data support the conclusion that symptomatic COVID-19 infection is associated with task-related, functional imaging and self-reported indices of cognitive dysfunction as well as psychiatric symptoms. In some cases, these findings appear to be more amplified among women than men, and among older women than younger.

Source: Hall PA, Ayaz H, Meng G, Hudson A, Sakib MN, Quah ACK, Agar TK, Lee JA, Boudreau C, Fong GT. Neurocognitive and psychiatric symptoms following infection with COVID-19: Evidence from laboratory and population studies. Brain Behav Immun Health. 2023 Mar;28:100595. doi: 10.1016/j.bbih.2023.100595. Epub 2023 Jan 24. PMID: 36713476; PMCID: PMC9870612. https://www.sciencedirect.com/science/article/pii/S2666354623000091?via%3Dihub (Full study)

The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures

Highlights:

  • None of the SARS-CoV-2 original, delta, or omicron strains can infect neurons.
  • The SARS-CoV-2 original, delta, and omicron strains can infect microglia.
  • The CNS cells differentiated from hiPSCs are useful to investigate the infectivity of the virus.

Abstract:

COVID-19 causes neurological damage, systemic inflammation, and immune cell abnormalities. COVID-19-induced neurological impairment may be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which directly infects cells of the central nervous system (CNS) and exerts toxic effects. Furthermore, SARS-CoV-2 mutations occur constantly, and it is not well understood how the infectivity of the virus to cells of the CNS changes as the virus mutates.

Few studies have examined whether the infectivity of cells of CNS – neural stem/progenitor cells (NS/PCs), neurons, astrocytes, and microglia – varies among SARS-CoV-2 mutant strains. In this study, therefore, we investigated whether SARS-CoV-2 mutations increase infectivity to CNS cells, including microglia.

Since it was essential to demonstrate the infectivity of the virus to CNS cells in vitro using human cells, we generated cortical neurons, astrocytes, and microglia from human induced pluripotent stem cells (hiPSCs). We added pseudotyped lentiviruses of SARS-CoV-2 to each type of cells, and then we examined their infectivity. We prepared three pseudotyped lentiviruses expressing the S protein of the original strain (the first SARS-CoV-2 discovered in the world), the Delta variant, and the Omicron variant on their envelopes and analyzed differences of their ability to infect CNS cells. We also generated brain organoids and investigated the infectivity of each virus.

The viruses did not infect cortical neurons, astrocytes, or NS/PCs, but microglia were infected by the original, Delta, and Omicron pseudotyped viruses. In addition, DPP4 and CD147, potential core receptors of SARS-CoV-2, were highly expressed in the infected microglia, while DPP4 expression was deficient in cortical neurons, astrocytes, and NS/PCs.

Our results suggest that DPP4, which is also a receptor for Middle East respiratory syndrome-coronavirus (MERS-CoV), may play an essential role in the CNS. Our study is applicable to the validation of the infectivity of viruses that cause various infectious diseases in CNS cells, which are difficult to sample from humans.

Source: Kase Y, Sonn I, Goto M, Murakami R, Sato T, Okano H. The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures. Exp Neurol. 2023 Mar 11;363:114379. doi: 10.1016/j.expneurol.2023.114379. Epub ahead of print. PMID: 36914084; PMCID: PMC10008041. https://www.sciencedirect.com/science/article/pii/S0014488623000638?via%3Dihub (Full text)

Potential Prion Involvement in Long COVID-19 Neuropathology, Including Behavior

Abstract:

Prion is a term used to describe a protein infectious particle responsible for several neurodegenerative diseases in mammals, e.g., Creutzfeldt-Jakob disease. The novelty is that it is protein based infectious agent not involving a nucleic acid genome as found in viruses and bacteria.

Prion disorders exhibit, in part, incubation periods, neuronal loss, and induce abnormal folding of specific normal cellular proteins due to enhancing reactive oxygen species associated with mitochondria energy metabolism. These agents may also induce memory, personality and movement abnormalities as well as depression, confusion and disorientation.

Interestingly, some of these behavioral changes also occur in COVID-19 and mechanistically include mitochondrial damage caused by SARS-CoV-2 and subsequent production of reactive oxygen species. Taken together, we surmise, in part, long COVID may involve the induction of spontaneous prion emergence, especially in individuals susceptible to its origin may thus explain some of its manisfestions post-acute viral infection.

Source: Stefano GB, Büttiker P, Weissenberger S, Anders M, Raboch J, Ptacek R, Kream RM. Potential Prion Involvement in Long COVID-19 Neuropathology, Including Behavior. Cell Mol Neurobiol. 2023 Mar 28:1–6. doi: 10.1007/s10571-023-01342-8. Epub ahead of print. PMID: 36977809; PMCID: PMC10047479. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10047479/ (Full text)

Association of Laparoscopically-confirmed Endometriosis with Long COVID: A Prospective Cohort Study

Abstract:

Background: Women are at greater risk than men of developing chronic inflammatory conditions and of developing ‘long COVID.’ However, few gynecologic health risk factors for long COVID have been identified. Endometriosis is a common gynecological disorder associated with chronic inflammation, immune dysregulation, and comorbid presentation with autoimmune and clotting disorders, all of which are pathophysiologic mechanisms proposed for long COVID. Therefore, we hypothesized that women with a history of endometriosis may be at greater risk of developing long COVID.

Objective: To investigate the association between history of endometriosis prior to SARS-CoV-2 infection and risk of long COVID.

Methods: We followed 46,579 women from two ongoing prospective cohort studies: the Nurses’ Health Study II and the Nurses’ Health Study 3, who participated in a series of COVID-19-related surveys administered from April 2020 to November 2022. Laparoscopic diagnosis of endometriosis was documented prospectively in main cohort questionnaires prior to the pandemic (1993-2020) with high validity. SARS-CoV-2 infection (confirmed by antigen, PCR, or antibody test) and CDC-defined long-term COVID-19 symptoms (≥4 weeks) were self-reported during follow-up. Among individuals with SARS-CoV-2 infection, we fit Poisson regression models to assess the associations between endometriosis and risk of long COVID-19 symptoms, with adjustment for potential confounding variables (demographics, body mass index, smoking status, history of infertility, and history of chronic diseases).

Results: Among 3650 women in our sample with self-reported SARS-CoV-2 infections during follow-up, 386 (10.6%) had a history of endometriosis with laparoscopic confirmation and 1598 (43.8%) reported experiencing long COVID symptoms. The majority of women were Non-Hispanic White (95.4%), with a median age of 59 years (interquartile range=44-65). Women with a history of laparoscopically-confirmed endometriosis had a 22% greater risk of developing long COVID (adjusted RR=1.22, 95% CI=1.05-1.42), compared to those who had never been diagnosed with endometriosis. The association was stronger when we defined long COVID as having symptoms ≥8 weeks (RR=1.28, 95% CI=1.09-1.50). We observed no statistically significant differences in the relationship between endometriosis and long COVID by age, infertility history, or comorbidity with uterine fibroids, although there was a suggestive trend that women <50 years may be at higher risk (<50 years, RR=1.37, 95% CI=1.00-1.88; ≥50 years, RR=1.19, 95% CI=1.01-1.41). Among persons who developed long COVID, women with endometriosis reported on average one additional long-term symptom compared to women without endometriosis.

Conclusions and relevance: Our findings suggest that those with a history of endometriosis may be at modestly increased risk for long COVID. Health care providers should be aware of endometriosis history when treating patients for signs of persisting symptoms post-SARS-CoV-2 infection. Future studies should investigate the potential biological pathways underlying these associations.

Source: Wang S, Farland LV, Gaskins AJ, Mortazavi J, Wang YX, Tamimi RM, Rich-Edwards JW, Zhang D, Terry KL, Chavarro JE, Missmer SA. Association of Laparoscopically-confirmed Endometriosis with Long COVID: A Prospective Cohort Study. Am J Obstet Gynecol. 2023 Mar 25:S0002-9378(23)00177-1. doi: 10.1016/j.ajog.2023.03.030. Epub ahead of print. PMID: 36972892. https://pubmed.ncbi.nlm.nih.gov/36972892/ https://www.ajog.org/article/S0002-9378(23)00177-1/pdf (Full text available as PDF file)

Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem?

Abstract:

The coronavirus pandemic that began in 2019 continues. COVID-19 adversely affects human health not only in the acute, but also in the long-term period of the disease: in a large percentage of cases, health is not fully restored after long periods, requires medical intervention, and is often difficult to correct.

Researchers noted during the first wave of the pandemic in 2020 that about 10-20% of patients did not fully recover by three weeks from disease onset and the possible duration of the recovery period remains insufficiently clear, as do the reasons for differences in course during this period. Prolonged recovery after viral infection is not a feature exclusive to COVID-19, which does not facilitate the management of patients with post-COVID syndrome (PCS).

The mental health impact of COVID-19 is significant, with at least 30% of recovered patients likely to have symptoms of anxiety and/or depression after the acute phase has passed. Since the onset of COVID-19, there has been an increase in sleep disorders by 42%, with every third COVID-19 survivor reporting sleep complaints. In PCS, this condition is referred to as coronasomnia.

The success of therapy for this condition depends on identifying and correcting patients’ mental disorders, as anxiety and depression are often accompanied by sleep disorders this results in a bidirectional interaction between mental disorders and sleep quality. This article presents data on the anti-anxiety drugs Noofen and Adaptol, which help to correct the manifestations of PCS with sleep disorders.

Source: Kotova OV, Medvedev VE, Poluektov MG, Belyaev AA, Akarachkova ES. Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem? Neurosci Behav Physiol. 2023;53(1):16-20. doi: 10.1007/s11055-023-01385-w. Epub 2023 Mar 11. PMID: 36969358; PMCID: PMC10006556. https://link.springer.com/article/10.1007/s11055-023-01385-w (Full text available as PDF file)

 

How do long COVID patients perceive their current life situation and occupational perspective? Results of a qualitative interview study in Germany

Abstract:

Introduction: Many people experience persistent or new-onset symptoms such as fatigue or cognitive problems after an acute infection with COVID-19. This phenomenon, known as long COVID, impacts physical and mental wellbeing, and may affect perceived quality of life and occupational perspectives likewise. The aim of this study is to gain a deeper understanding of how people with long COVID experience health-related restrictions in their daily life and their occupational situation, and to identify key challenges they face.

Methods: Guided qualitative interviews were conducted with 25 people with long COVID. The interviews were transcribed according to Dresing/Pehl and Kuckartz and analyzed using qualitative content analysis. Afterward, a systematic comparison of the data and a reflection under consideration of lifeworld-theoretical approaches (Berger and Luckmann) were carried out.

Results: The interviews revealed that many participants have severe symptoms which strongly impair them in perform daily and work-related activities, and in their personal interests. Many interviewees already reach their stress limit during routine household activities or childcare. Of the 25 participants, 19 experienced limitations in pursuing leisure activities, and 10 of the 23 interviewees with jobs reported being on sick leave for several months. Several respondents who had vocational reintegration are still affected by ongoing symptoms that affect their work performance considerably. This leads to uncertainty, role conflicts, a decline in social contacts, and decreased incomes, which contribute to an impairment in their quality of life.

Conclusions: This study shows the huge need for specific support for people with long COVID in different areas of life. To prevent people with long COVID from finding themselves in social and economic precarity, decision-makers should develop strategies to systematically support them in their sustainable reintegration into the workforce. The focus should be on creating long COVID-sensitive workplaces, compensating for decreased incomes, and improving access to relief services such as vocational reintegration. We argue, that a shift of perspectives is necessary and that long COVID should be considered rather as a “social disease” with considerably impairments in the social life of those affected.

Trial registration: The study is registered in the German register for clinical trials (DRKS00026007).

Source: Schmachtenberg T, Müller F, Kranz J, Dragaqina A, Wegener G, Königs G, Roder S. How do long COVID patients perceive their current life situation and occupational perspective? Results of a qualitative interview study in Germany. Front Public Health. 2023 Mar 9;11:1155193. doi: 10.3389/fpubh.2023.1155193. PMID: 36969629; PMCID: PMC10034079. https://www.frontiersin.org/articles/10.3389/fpubh.2023.1155193/full (Full text)

Functional limitations in individuals with long COVID

Abstract:

Objectives: To examine the extent of long-term functional deficits experienced by individuals hospitalized for COVID-19. Specific objectives were to: 1. describe changes in perceived global health, mobility, participation in daily activities, and employment status from pre-COVID-19 to ≥2 months following infection; and 2. evaluate factors associated with change in function.

Design: We conducted a telephone survey (at least 2 months post infection).

Setting: Population-based study of adults living at home.

Participants: Adult residents in Laval, Quebec, who were discharged home post-hospitalization for COVID-19.

Interventions: Not applicable MAIN OUTCOME MEASURES: Participants responded to a standard questionnaire (Covid-19 Yorkshire Rehabilitation Screen) regarding persistent symptoms and limitations in daily functioning. We calculated the prevalence of changes in perceived global health, mobility, personal care, participation in daily activities, and employment and evaluated associated factors using bivariate analysis and multivariable logistic regression.

Results: Almost all participants (94%) were more fatigued and reported deterioration of their global health status (90%) at least three months after infection. The majority were more short of breath, and experienced pain and anxiety. The change in outcomes indicate a substantial reduction in those reporting ‘good’ health status, mobility, personal care, and daily activities, and less employment. Time since diagnosis was significantly associated with global health, mobility, and participation in daily activities.

Conclusion: This population-based study suggests that individuals hospitalized for COVID-19 infection have symptoms that impact daily functional activities many months after infection. It is imperative that the impact of infection is better understood so that those affected long-term can receive the needed services.

Source: Mazer B, Feldman DE. Functional limitations in individuals with long COVID. Arch Phys Med Rehabil. 2023 Mar 24:S0003-9993(23)00162-4. doi: 10.1016/j.apmr.2023.03.004. Epub ahead of print. PMID: 36966957; PMCID: PMC10036292. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10036292/ (Full text)

A prospective cohort study assessing the relationship between long-COVID symptom incidence in COVID-19 patients and COVID-19 vaccination

Abstract:

Current studies about the long-term effects of COVID-19 show a wide range of symptoms. This prospective cohort study aimed to find the incidence of long-COVID symptoms and the associated risk factors.

We followed 669 confirmed COVID-19 patients. Sociodemographic and clinical data were extracted from medical records and collected via semi-structured telephone interviews on days 10, 30, 60, and 90. The incidence of long-COVID symptoms was 41.6% (95% CI 37.8-45.4%). Females [aOR = 1.5 (95% CI 1.1-2.3)], the elderly [aOR = 4.9 (95% CI 2.0-11.3)], and those who required hospitalization [aOR = 5.0 (95% CI 1.3-3.7)] were at a higher risk of developing long-COVID. Patients with dyspnea at day 10 [aOR: 2.4 (95% CI 1.6-3.7] and fatigue at day 60 [aOR: 3.1 (95% CI 1.5-6.3] were also at risk. While non-vaccinated patients were almost seven times more likely to report long-COVID symptoms than vaccinated patients [aOR: 6.9 (95% CI 4.2-11.3)].

In conclusion, long-COVID was common among COVID-19 patients, with higher rates among females, older age groups, hospitalized patients, and those with dyspnea and fatigue, while vaccination provided protection. Interventions should educate health professionals, raise general public awareness about the risks and consequences of Long COVID, and the value of vaccination.

Source: Abu Hamdh B, Nazzal Z. A prospective cohort study assessing the relationship between long-COVID symptom incidence in COVID-19 patients and COVID-19 vaccination. Sci Rep. 2023 Mar 25;13(1):4896. doi: 10.1038/s41598-023-30583-2. PMID: 36966161; PMCID: PMC10039348. https://www.nature.com/articles/s41598-023-30583-2 (Full text)