Increased insulin resistance due to Long COVID is associated with depressive symptoms and partly predicted by the inflammatory response during acute infection

Abstract:

Background: Some months after the remission of acute COVID-19, some individuals show depressive symptoms, which are predicted by increased peak body temperature (PBT) and decreased blood oxygen saturation (SpO2). No data indicate whether Long COVID is associated with increased insulin resistance (IR) in association with neuroimmune and oxidative (NIO) processes.

Methods: This case control and retrospective cohort study used the homeostasis Model Assessment 2 (HOMA2) calculator© to compute β-cell function, insulin sensitivity and resistance (HOMA2-IR) and measured the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HAMD) in 86 Long COVID patients and 39 controls.

Results: Long COVID (3-4 months after the acute infection) is accompanied by increased HOMA2-IR, fasting blood glucose, and insulin levels; 33.7% of the patients versus 0% of the controls had HOMA2-IR values >1.8, suggesting IR. Increased IR was predicted by PBT during acute infection, and associated with depressive symptoms above and beyond the effects of NIO pathways (NLRP3 inflamasome, myeloperoxidase, protein oxidation). There were no significant associations between increased IR and the activated NIO pathways during Long COVID.

Conclusion: Long COVID is associated with new-onset IR which may contribute to the onset of depressive symptoms due to Long COVID by enhancing overall neurotoxicity.

Source: Al-Hakeim HK, Al-Rubaye HT, Jubran AS, Almulla AF, Moustafa SR, Maes M. Increased insulin resistance due to Long COVID is associated with depressive symptoms and partly predicted by the inflammatory response during acute infection. Braz J Psychiatry. 2023 Mar 14. doi: 10.47626/1516-4446-2022-3002. Epub ahead of print. PMID: 36917827. https://pubmed.ncbi.nlm.nih.gov/36917827/ 

Comparison of Symptoms in Covid-19 Acute Infection and Long Covid-19

Abstract:

Background: Relatively little is known about the clinical course of covid-19 and the differences between the symptoms of covid-19 in acute phase of infection and the symptoms of long covid-19 in people with milder outpatient illnesses.

Objective: To compare clinical characteristics of covid-19 in acute infection with long covid-19 (presence of prolonged symptoms for at least 12 weeks, lasting at least 2 months, after acute covid-19 infection, and that are not explained by an alternative diagnosis).

Methodology: Comparison of secondary data among tow previous observational, longitudinal and prospective studies: 1) patients with post-acute covid-19 syndrome from March 15, 2020 to March 31, 2021; and 2) patients with Long covid-19 from March 15, 2020 to October 31, 2022, in the same population in general medicine.

Results: 33 covid-19 in acute phase, with 138 symptoms and 27 Long covid-19 cases with 44 symptoms were included. Respiratory symptoms predominated in both groups. Symptoms in Long covid-19 cases were significantly lower in general symptoms (X2= 5.9539. p= .014), and higher in Circulatory and Genitourinary system (Fisher exact test= 0.05).

Conclusion: Both in Long covid-19 and in covid-19 acute phase respiratory symptoms predominate. But they differ in that the symptoms of long covid-19 are less general than those of covid-19 acute phase, and present more symptoms of almost all organs and systems, those of the Circulatory and Genitourinary system being significant. The symptoms of Long covid-19 vs. acute phase are more debilitating and clinically heterogeneous.

Source: Turabian, Jose. (2023). Comparison of Symptoms in Covid-19 Acute Infection and Long Covid-19. 2694-5843. 10.36266/JCMHR/170.  https://www.researchgate.net/publication/369088222_Comparison_of_Symptoms_in_Covid-19_Acute_Infection_and_Long_Covid-19 (Full text)

Long COVID and children’s rights

Abstract:

This policy note calls for the recognition of long COVID as a children’s rights issue in the UK. While children have been affected by school closures and lockdown restrictions throughout the pandemic, the relatively low rates of COVID-related hospitalizations and deaths among children have led to their de-prioritization in efforts to reduce the spread of the SARS-CoV-2 virus. Yet infection rates are extremely high among children in the UK, particularly secondary school students, and early studies suggest that many are not recovering for up to a year after infection.

Prolonged illness following infection, ‘long COVID’, has implications for children’s rights to education, health, and a private and family life, among others. By extension, children have a right to have their best interests taken into consideration in policy-making processes relating to long COVID. The policy note thus argues that we must recognize the significance of long COVID in children and, upon this basis, call upon the State to address its human rights implications.

Source: Vivek Bhatt, Long COVID and children’s rights, Journal of Human Rights Practice, 2023;, huac047, https://doi.org/10.1093/jhuman/huac047 (Full text)

Long-COVID Inducement Mechanism Based on the Path Module Correlation Coefficient

Abstract:

As the number of COVID-19 cases increases, the long-COVID symptoms become the focus of clinical attention. Based on the statistical analysis of long-COVID symptoms in European and Chinese populations, this study proposes the path module correlation coefficient, which can estimate the correlation between two modules in a network, to evaluate the correlation between SARS-CoV-2 infection and long-COVID symptoms, providing a theoretical support for analyzing the frequency of long-COVID symptoms in European and Chinese populations.
The path module correlation coefficients between specific COVID-19-related genes in the European and Chinese populations and genes that may induce long-COVID symptoms were calculated. The results showed that the path module correlation coefficients were completely consistent with the frequency of long-COVID symptoms in the Chinese population, but slightly different in the European population. Furthermore, the cathepsin C (CTSC) gene was found to be a potential COVID-19-related gene by a path module correlation coefficient correction rate.
Our study can help to explore other long-COVID symptoms that have not yet been discovered and provide a new perspective to research this syndrome. Meanwhile, the path module correlation coefficient correction rate can help to find more species-specific genes related to COVID-19 in the future.
Source: Liu Z, Yin Z, Mi Z, Guo B. Long-COVID Inducement Mechanism Based on the Path Module Correlation Coefficient. Mathematics. 2023; 11(6):1368. https://doi.org/10.3390/math11061368 (Full text)

Should We Expect an Increase in the Number of Cancer Cases in People with Long COVID?

Abstract:

The relationship between viral infections and the risk of developing cancer is well known. Multiple mechanisms participate in and determine this process. The COVID-19 pandemic caused by the SARS-CoV-2 virus has resulted in the deaths of millions of people worldwide. Although the effects of COVID-19 are limited for most people, a large number of people continue to show symptoms for a long period of time (long COVID). Several studies have suggested that cancer could also be a potential long-term complication of the virus; however, the causes of this risk are not yet well understood. In this review, we investigated arguments that could support or reject this possibility.
Source: Amiama-Roig A, Pérez-Martínez L, Rodríguez Ledo P, Verdugo-Sivianes EM, Blanco J-R. Should We Expect an Increase in the Number of Cancer Cases in People with Long COVID? Microorganisms. 2023; 11(3):713. https://doi.org/10.3390/microorganisms11030713 (Full text)

Long COVID-six months of prospective follow-up of changes in symptom profiles of non-hospitalised children and young people after SARS-CoV-2 testing: A national matched cohort study (The CLoCk) study

Abstract:

Background: Little is known about the prevalence and natural trajectory of post-COVID symptoms in young people, despite very high numbers of young people having acute COVID. To date, there has been no prospective follow-up to establish the pattern of symptoms over a 6-month time period.

Methods: A non-hospitalised, national sample of 3,395 (1,737 SARS-COV-2 Negative;1,658 SARS-COV-2 Positive at baseline) children and young people (CYP) aged 11-17 completed questionnaires 3 and 6 months after PCR-confirmed SARS-CoV-2 infection between January and March 2021 and were compared with age, sex and geographically-matched test-negative CYP.

Results: Three months after a positive SARS-CoV-2 PCR test, 11 of the 21 most common symptoms reported by >10% of CYP had reduced. There was a further decline at 6 months. By 3 and 6 months the prevalence of chills, fever, myalgia, cough and sore throat of CYP who tested positive for SARS-CoV-2 reduced from 10-25% at testing to <3%. The prevalence of loss of smell declined from 21% to 5% at 3 months and 4% at 6 months. Prevalence of shortness of breath and tiredness also declined, but at a lower rate. Among test-negatives, the same common symptoms and trends were observed at lower prevalence’s. Importantly, in some instances (shortness of breath, tiredness) the overall prevalence of specific individual symptoms at 3 and 6 months was higher than at PCR-testing because these symptoms were reported in new cohorts of CYP who had not reported the specific individual symptom previously.

Conclusions: In CYP, the prevalence of specific symptoms reported at time of PCR-testing declined with time. Similar patterns were observed among test-positives and test-negatives and new symptoms were reported six months post-test for both groups suggesting that symptoms are unlikely to exclusively be a specific consequence of SARS-COV-2 infection. Many CYP experienced unwanted symptoms that warrant investigation and potential intervention.

Source: Stephenson T, Pinto Pereira SM, Nugawela MD, McOwat K, Simmons R, Chalder T, Ford T, Heyman I, Swann OV, Fox-Smith L, Rojas NK, Dalrymple E, Ladhani SN, Shafran R; CLoCk Consortium. Long COVID-six months of prospective follow-up of changes in symptom profiles of non-hospitalised children and young people after SARS-CoV-2 testing: A national matched cohort study (The CLoCk) study. PLoS One. 2023 Mar 6;18(3):e0277704. doi: 10.1371/journal.pone.0277704. PMID: 36877677; PMCID: PMC9987792. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9987792/ (Full text)

Understanding Long COVID Syndrome: An Up to the Minute Fret

Abstract:

The Severe Acute Respiratory Syndrome Corona Virus 2 (SARSCoV-2) virus-induced corona virus disease 2019 (COVID-19) has had a global spread. Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) rst emerged in Wuhan, China, in December 2019, and the infection spread rapidly across the world. The disease caused by the virus was named corona virus disease in 2019, and was declared a global pandemic by the World Health Organization (WHO) in March 2020. While the symptoms are mild or moderate in most patients, severe pneumonia can develop in 15%, and Acute Respiratory Distress Syndrome (ARDS), septic shock, and multiple organ failure in 5%. A comprehensive strategy for precautions includes hand washing, social distancing, isolation and mask-wearing. Besides, vaccines play an essential role in preventing the spread.

Long COVID or long-haul COVID (also known as post-COVID-19 syndrome, post-COVID-19 condition, post-acute sequelae of COVID-19 (PASC), or chronic COVID syndrome (CCS) is a condition characterized by long-term health problems persisting or appearing after the typical recovery period of COVID-19. Although studies into long COVID are under way, as of May 2022 there is no consensus on the definition of the term.

Long COVID has been described as having the potential to affect nearly every organ system, causing further conditions (sequelae) including respiratory system disorders, nervous system and neurocognitive disorders, mental health disorders, metabolic disorders, cardiovascular disorders, gastrointestinal disorders, musculoskeletal pain, and anemia. The most commonly reported symptoms of long COVID are fatigue and memory problems. Many other symptoms have also been reported, including malaise, headaches, shortness of breath, anosmia (loss of smell), parosmia (distorted smell), muscle weakness, low-grade fever, and cognitive dysfunction. Overall, it is considered by default to be a diagnosis of exclusion.

Source: Gomes, Richmond. (2023). Understanding Long COVID Syndrome: An Up to the Minute Fret. 04. 1-7.  https://www.researchgate.net/publication/369037934_Understanding_Long_COVID_Syndrome_An_Up_to_the_Minute_Fret (Full text)

Ambient air pollution exposure linked to long COVID among young adults: a nested survey in a population-based cohort in Sweden

Summary:

Background: Post COVID-19 conditions, also known as long COVID, are of public health concern, but little is known about their underlying risk factors. We aimed to investigate associations of air pollution exposure with long COVID among Swedish young adults.

Methods: We used data from the BAMSE (Children, Allergy, Environment, Stockholm, Epidemiology [in Swedish]) cohort. From October 2021 to February 2022 participants answered a web-questionnaire focusing on persistent symptoms following acute SARS-CoV-2 infection. Long COVID was defined as symptoms after confirmed infection with SARS-CoV-2 lasting for two months or longer. Ambient air pollution levels (particulate matter ≤2.5 μm [PM2.5], ≤10 μm [PM10], black carbon [BC] and nitrogen oxides [NOx]) at individual-level addresses were estimated using dispersion modelling.

Findings: A total of 753 participants with SARS-CoV-2 infection were included of whom 116 (15.4%) reported having long COVID. The most common symptoms were altered smell/taste (n = 80, 10.6%), dyspnea (n = 36, 4.8%) and fatigue (n = 34, 4.5%). Median annual PM2.5 exposure in 2019 (pre-pandemic) was 6.39 (interquartile range [IQR] 6.06–6.71) μg/m3. Adjusted Odds Ratios (95% confidence intervals) of PM2.5 per IQR increase were 1.28 (1.02–1.60) for long COVID, 1.65 (1.09–2.50) for dyspnea symptoms and 1.29 (0.97–1.70) for altered smell/taste. Positive associations were found for the other air pollutants and remained consistent across sensitivity analyses. Associations tended to be stronger among participants with asthma, and those having had COVID during 2020 (versus 2021).

Interpretation: Ambient long-term PM2.5 exposure may affect the risk of long COVID in young adults, supporting efforts for continuously improving air quality.

Source: Zhebin Yu, Sandra Ekström, Tom Bellander, Petter Ljungman, Göran Pershagen, Kristina Eneroth et al. Ambient air pollution exposure linked to long COVID among young adults: a nested survey in a population-based cohort in Sweden. The Lancet. Published: March 07, 2023 DOI:https://doi.org/10.1016/j.lanepe.2023.100608 (Full text)

Autoimmunity in Long Covid and POTS

Abstract:

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalised immune dysregulation. At the same time, multiple autoantibodies are identified in both Covid-related autonomic disorders and non-Covid autonomic disorders, implying a possible underlying autoimmune pathology. The lack of specificity of these findings precludes direct interpretations of cause and association, but prevalence with its supporting evidence is compelling.

In this review, we discuss the role of the autonomic nervous and immune systems in Covid and Long Covid and their potential influence on symptoms and clinical practice. Additionally, overlap with non-Covid autonomic dysfunction is considered. Understanding these new disorders can inform both neuro-immunology and Long Covid management.

Source: Fatema-Zahra El-Rhermoul, Artur Fedorowski, Philip Eardley, Patricia Taraborrelli, Dimitrios Panagopoulos, Richard Sutton, Phang Boon Lim, Melanie Dani, Autoimmunity in Long Covid and POTS, Oxford Open Immunology, 2023;, iqad002, https://doi.org/10.1093/oxfimm/iqad002 (Full text available as PDF file)

A neuroinflammatory paradigm can explain Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome and Post-COVID-19 Fatigue Syndrome

Abstract

This thesis illustrates the development of a neuroinflammatory paradigm for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), applicable to Long-COVID related “Post-COVID-19 Fatigue Syndrome” (PCFS).

The brain being devoid of nociceptors, in combination with neuroimaging technology lacking sufficient sensitivity, helps to explain why the chronic but low-level neuroinflammation purported to be present in the brains of ME/CFS (and PCFS) sufferers has gone unreported by patients, and has been largely undetected by scientists, until more recently. Over-activation of microglia and astrocytes is increasingly being proposed to be at the heart of ME/CFS (and PCFS) pathophysiology.

A key Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) study (2014) provided evidence of glial-cell over-activity, implicating neuroinflammation within the brain’s limbic system, of ME/CFS patients. Other cerebral spinal fluid and neuroimaging studies, including a more recent Magnetic Resonance Spectroscopy (MRS)/MRI Thermometry study (2019), have added support to this concept.

Resultant dysfunction of the limbic system and its closely-connected hypothalamus, which in turn leads to a disturbed autonomic nervous system (ANS) and dysfunctional hypothalamic-pituitary-adrenal-axis (HPA-axis) could then account for the diverse range of symptoms reported in ME/CFS (and PCFS). These symptoms include chronic fatigue, flu-like malaise, mood, memory and cognitive problems (limbic system), sleep, taste, visual and thermostatic-control problems (hypothalamus), gastro-intestinal disturbance, cardiovascular problems and hypotension (ANS), as well as increased frequency of urination and lower blood cortisol levels (HPA-axis).

A dysfunctional hypothalamic paraventricular nucleus (PVN), a potentially vulnerable site, within the brains of genetically susceptible people, which functions normally as a stress-control integrator, is proposed to be at the core of ME/CFS (and PCFS) aetiology and pathophysiology.

It is proposed that all triggers of ME/CFS, be they viral (Epstein-Barr Virus is the most common trigger), or non-viral; including other infectious diseases, multiple vaccinations, emotional trauma or chemical toxin shock, share a common triggering mechanism. They are each proposed to manifest themselves as severe physiological stressors, which by a combination of humoral and neural routes, target, the hypothalamic PVN, of genetically susceptible individuals. By exceeding an intrinsic stress-threshold pertaining to the complex neurological circuitry, within the hypothalamic PVN, the triggering stressor is proposed to overload it into a (permanently) iii dysfunctional state.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), which causes Coronavirus Disease 2019 (COVID-19), in common with the triggering stressors of ME/CFS, also manifests itself as a severe physiological stressor, due to a cytokine surge at the site of the primary infection (the lungs). This particular stressor is, also, proposed to target the hypothalamic PVN, in genetically susceptible people, thus triggering PCFS. Life’s ongoing physiological stressors, such as physical, mental overexercise, chemical toxin exposure, emotional and financial stress, all of which are known to exacerbate and perpetuate ME/CFS (as well as PCFS) could do so by then targeting a now “compromised” (possibly inflamed) stress-sensitive hypothalamic PVN, by similar routes.

Then if an alternative, but variable (according to fluctuating neuroinflammation of the hypothalamic PVN, itself) stress threshold was exceeded, commonly reported post-exertional malaise (PEM) episodes, more problematic flare-ups, and even more severe prolonged and characteristic relapses could ensue.

It is proposed that a dysfunctional hypothalamic PVN, thereby, acts as an epicentre to a radiating neuroinflammatory response within the brains of ME/CFS (and PCFS) sufferers. A neuroinflammatory pathway, as proposed to be shared by the early-onset stages of several progressive neuroinflammatory (neurodegenerative) diseases could also be shared by ME/CFS, and PCFS. Indeed, this pathway could be shared by other potentially nonprogressive neuroinflammatory disorders, such as the closely-related fibromyalgia, mental health disorders, epilepsy, and migraines.

Might then the “drivers” of the inflammatory process, which sustain glial-cell activation (and neuroinflammation), in ME/CFS (and PCFS), be the perpetuating stressors, themselves, acting in combination with a now “compromised” and stress-sensitive hypothalamic PVN? If so, what then might be the mechanistic detail linking a stressor-targeted hypothalamic PVN and microglial activation in ME/CFS (and PCFS)?

One attractive scenario requiring further investigation involves the release of corticotrophin releasing hormone (CRH), which is released naturally by the hypothalamic PVN due to stress. The chronic release of CRH from a stress-sensitive, dysfunctional hypothalamic PVN might induce microglia activation, leading to chronic neuroinflammation, via the stimulation of mast-cells.

Two papers were published in relation to this neuroinflammatory paradigm for ME/CFS (2018, 2019), followed by another paper (2021), in which a paradigm was presented to explain the more recently emergent, but equally perplexing, Long-COVID related “PostCOVID-19 Fatigue Syndrome” (PCFS).

The neuroinflammatory model presented is both iv coherent and unifying for all triggering stressors and perpetuating stressors of ME/CFS (& PCFS), without the need for subtypes (as many other models require), but it does require validation. To this effect, it is hoped that this neuroinflammatory model will be both thought-provoking, as well as providing a framework for scientific researchers to test, critique, modify, and develop, into the future.

More brain-focussed research, using increasingly sophisticated neuroimaging technology (especially enhanced PET/MRI) is recommended. Then, a brain-signature for both ME/CFS (and PCFS) might even become attainable, within the next decade, perhaps.

Long-COVID related PCFS, affecting millions of people worldwide, presents a golden opportunity for in-depth longitudinal neuroimaging studies (following patients through relapse-recovery cycles) to develop a better understanding of PCFS (and ME/CFS) pathophysiology.

Source: Mackay, A. A neuroinflammatory paradigm can explain Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome and Post-COVID-19 Fatigue Syndrome. PhD Thesis. University of Otago, New Zealand.  https://ourarchive.otago.ac.nz/bitstream/handle/10523/15089/MackayAngus2021PhD.pdf?sequence=1&isAllowed=y (PDF file)