Psychological outcomes of COVID-19 survivors at sixth months after diagnose: the role of kynurenine pathway metabolites in depression, anxiety, and stress

Abstract:

Coronavirus disease 2019 (COVID-19) has resulted in long-term psychiatric symptoms because of the immunologic response to the virus itself as well as fundamental life changes related to the pandemic. This immune response leads to altered tryptophan (TRP)-kynurenine (KYN) pathway (TKP) metabolism, which plays an essential role in the pathophysiology of mental illnesses. We aimed to define TKP changes as a potential underlying mechanism of psychiatric disorders in post-COVID-19 patients.

We measured plasma levels of several TKP markers, including KYN, TRP, kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), and quinolinic acid (QUIN), as well as the TRP/KYN, KYNA/3-HK, and KYNA/QUIN ratios, in 90 post-COVID-19 patients (on the first day of hospitalization) and 59 healthy controls (on the first admission to the Check-Up Center). An online questionnaire that included the Depression, Anxiety and Stress Scale-21 (DASS-21) was used 6 months after the initial assessment in both groups.

A total of 32.2% of participants with COVID-19 showed depressive symptoms, 21.1% exhibited anxiety, and 33.3% had signs of stress at follow-up, while 6.6% of healthy controls exhibited depressive and anxiety symptoms and 18.6% had signs of stress. TRP and 3-HK were negative predictors of anxiety and stress, but KYN positively predicted anxiety and stress. Moreover, TRP negatively predicted depression, while KYNA/3-HK was a negative predictor of anxiety.

The correlation between depression, anxiety, and stress and TKP activation in COVID-19 could provide prospective biomarkers, especially the reduction in TRP and 3HK levels and the increase in KYN. Our results suggest that the alteration of TKP is not only a potential biomarker of viral infection-related long-term psychiatric disorders but also that the therapy targets future viral infections related to depression and anxiety.

Source: Kucukkarapinar M, Yay-Pence A, Yildiz Y, Buyukkoruk M, Yaz-Aydin G, Deveci-Bulut TS, Gulbahar O, Senol E, Candansayar S. Psychological outcomes of COVID-19 survivors at sixth months after diagnose: the role of kynurenine pathway metabolites in depression, anxiety, and stress. J Neural Transm (Vienna). 2022 Aug;129(8):1077-1089. doi: 10.1007/s00702-022-02525-1. Epub 2022 Jul 7. PMID: 35796878; PMCID: PMC9261222. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9261222/ (Full text)

Links between Serotonin Levels and Stress: Cortisol, Candida A./Mycetes, Omega 3/6 Ratio and Dysbiosis (Skatole/Indoxyl Sulfate) Role in Chronic Fatigue Syndrome (CFS) and Depression

Abstract:

Intestinal microbiota attracts daily attention of a growing number of study which have attempted to link gut dysbiosIs with a variety of disease states: irritable bowel syndrome (IBS), inflamed bowel disease (IBD), Crohn’s disease (CD), leaky gut syndrome (LGS), food intolerance, diabetes, metabolic syndrome, cancer, etc.

In our study we analyzed how intestinal dysbiosis may be related to chronic fatigue syndrome (CFS) and depression through the exchange of information through the gut-brain axis (GBA).

We studied 33 subjects, 13 males and 20 females, who reported CFS or/and depression: we investigated their salivary cortisol levels, blood serotonin, omega 3/6 ratio, intestinal dysbiosis (calculated on the urinary levels of indoxyl sulfate and skatole), and we looked for the presence of Candida a. or mycetes in the stool; the data accumulated with this research show a correlation between the presence of Candida a./miceti, indoxyl sulfate urine values beyond the physiological and low serotonin levels.

In addition, data analysis showed that the EPA/DHA values also show pro-inflammatory levels in case of dysbiosis and low serotonina levels. The relationship, however, with cortisol levels requires further research although this study showed a statistically significant positive correlation between these values, measured at specific times, and serotonin levels.

Aims: We investigated the relationship between stress (evaluated through the measurement of salivary cortisol levels) and gastrointestinal efficiency measured as a function of intestinal fermentative and putrefactive dysbiosis, evaluating the levels of urinary indoxyl sulfate in the first case (a possible correlation with the presence of Candida spp or Mycetes in the subjects feces was investigated), urinary skatole levels in the second one, in patients with chronic fatigue syndrome (SFC) and depression.

In these patients we also have studied omega 3/6 ratio, and finally we have analized the impact that the alteration of these parameters can have on the serotonin levels.

This research attemps to highlight the contact points, in some cases not so obvious, among these topics, contact points that, although they give us interesting indications, show the need to be further deepened by analyzing a larger amount of data.

Source: Orlandoni, D.; Di Fede, G.; Mantovani, M.; Nava, C.R.; Tomasi, M.; Fusi, P. Links between Serotonin Levels and Stress: Cortisol, Candida A./Mycetes, Omega 3/6 Ratio and Dysbiosis (Skatole/Indoxyl Sulfate) Role in Chronic Fatigue Syndrome (CFS) and Depression. Preprints 2023, 2023090253. https://doi.org/10.20944/preprints202309.0253.v1 https://www.preprints.org/manuscript/202309.0253/v1 (Full text available as PDF file)

Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia

Abstract:

Although the predominant symptom in fibromyalgia (FM) is muscle pain, and fatigue in chronic fatigue syndrome (CFS), differential diagnosis is very difficult. This research investigates the psychoneuroimmunoendocrine disorders of FM patients and ascertains whether a previous CFS diagnosis affected them.

Through accelerometry objective parameters, physical activity/sedentarism levels in relation to fatigue are studied, as well as whether perceived levels of stress, anxiety, and pain correspond to objective biomarkers, all of these with respect to a reference group (RG) of women without FM.

FM patients have a worse psychological state and perceived quality of life than those with RG. These perceived outcomes are consistent with impaired objective levels of a sedentary lifestyle, higher systemic levels of cortisol and noradrenaline, and lower levels of serotonin.

However, FM patients with a previous CFS diagnosis had lower systemic levels of IL-8, cortisol, oxytocin, and higher levels of adrenaline and serotonin than FM patients without diagnosed CFS.

In conclusion, while perceived health parameters do not detect differences, when objective neuroimmunoendocrine parameters related to stress, inflammation, pain, and fatigue are used, people with CFS could be overdiagnosed with FM. This reinforces the need for objective biomarker assessment of these patients for better diagnostic discrimination between both syndromes.

Source: Otero E, Gálvez I, Ortega E, Hinchado MD. Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia. Biomedicines. 2023; 11(5):1488. https://doi.org/10.3390/biomedicines11051488 https://www.mdpi.com/2227-9059/11/5/1488 (Full text)

Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study

Abstract:

Previous studies showed that people with Fibromyalgia (FM) suffer from dysautonomia. Dysautonomia consists of persistent autonomic nervous system hyperactivity at rest and hyporeactivity during stressful situations. There is evidence that parameters reflecting the complex interplay between the autonomic nervous system and the cardiovascular system during exercise can provide significant prognostic information. Therefore, this study aimed to investigate the differences between people with FM and healthy controls on heart rate variability (HRV) and salivary parameters (such as flow, protein concentration, enzymatic activities of amylase, catalase and glutathione peroxidase) in two moments: (1) at baseline, and (2) after an exercise fatigue protocol.

A total of 37 participants, twenty-one were people with fibromyalgia and sixteen were healthy controls, participated in this cross-sectional study. HRV and salivary samples were collected before and after an exercise fatigue protocol. The fatigue protocol consisted of 20 repetitions of knee extensions and flexions of the dominant leg at 180 °·s-1 (degrees per second).

Significant differences were found in the HRV (stress index, LF and HF variables) and salivary biomarkers (with a higher concentration of salivary amylase in people with FM compared to healthy controls). Exercise acute effects on HRV showed that people with FM did not significantly react to exercise. However, significant differences between baseline and post-exercise on HRV significantly induce alteration on the HRV of healthy controls. Catalase significantly increased after exercise in healthy controls whereas salivary flow significantly increased in women with FM after an exercise fatigue protocol.

Our study suggests that a higher α-amylase activity and an impaired HRV can be used as possible biomarkers of fibromyalgia, associated with a reduction in salivary flow without changes in HRV and catalase activity after a fatigue exercise protocol. More studies should be carried out in the future to evaluate this hypothesis, in order to find diagnostic biomarkers in fibromyalgia.

Source: Costa AR, Freire A, Parraca JA, Silva V, Tomas-Carus P, Villafaina S. Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study. Diagnostics (Basel). 2022 Sep 14;12(9):2220. doi: 10.3390/diagnostics12092220. PMID: 36140620; PMCID: PMC9497903. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9497903/ (Full text)

Nutritional deficiencies that may predispose to long COVID

Abstract:

Multiple nutritional deficiencies (MND) confound studies designed to assess the role of a single nutrient in contributing to the initiation and progression of disease states. Despite the perception of many healthcare practitioners, up to 25% of Americans are deficient in five-or-more essential nutrients. Stress associated with the COVID-19 pandemic further increases the prevalence of deficiency states. Viral infections compete for crucial nutrients with immune cells. Viral replication and proliferation of immunocompetent cells critical to the host response require these essential nutrients, including zinc. Clinical studies have linked levels of more than 22 different dietary components to the likelihood of COVID-19 infection and the severity of the disease. People at higher risk of infection due to MND are also more likely to have long-term sequelae, known as Long COVID.

Source: Schloss, J.V. Nutritional deficiencies that may predispose to long COVID. Inflammopharmacol (2023). https://doi.org/10.1007/s10787-023-01183-3 https://link.springer.com/article/10.1007/s10787-023-01183-3 (Full text)

Urine Metabolomics Exposes Anomalous Recovery after Maximal Exertion in Female ME/CFS Patients

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with unknown etiology or effective treatments. Post-exertional malaise (PEM) is a key symptom that distinguishes ME/CFS patients. Investigating changes in the urine metabolome between ME/CFS patients and healthy subjects following exertion may help us understand PEM.
The aim of this pilot study was to comprehensively characterize the urine metabolomes of eight female healthy sedentary control subjects and ten female ME/CFS patients in response to a maximal cardiopulmonary exercise test (CPET). Each subject provided urine samples at baseline and 24 h post-exercise. A total of 1403 metabolites were detected via LC-MS/MS by Metabolon® including amino acids, carbohydrates, lipids, nucleotides, cofactors and vitamins, xenobiotics, and unknown compounds.
Using a linear mixed effects model, pathway enrichment analysis, topology analysis, and correlations between urine and plasma metabolite levels, significant differences were discovered between controls and ME/CFS patients in many lipid (steroids, acyl carnitines and acyl glycines) and amino acid subpathways (cysteine, methionine, SAM, and taurine; leucine, isoleucine, and valine; polyamine; tryptophan; and urea cycle, arginine and proline).
Our most unanticipated discovery is the lack of changes in the urine metabolome of ME/CFS patients during recovery while significant changes are induced in controls after CPET, potentially demonstrating the lack of adaptation to a severe stress in ME/CFS patients.
Source: Glass KA, Germain A, Huang YV, Hanson MR. Urine Metabolomics Exposes Anomalous Recovery after Maximal Exertion in Female ME/CFS Patients. International Journal of Molecular Sciences. 2023; 24(4):3685. https://doi.org/10.3390/ijms24043685 https://www.mdpi.com/1422-0067/24/4/3685 (Full text available as PDF file)

Stress-Induced Transcriptomic Changes in Females with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Reveal Disrupted Immune Signatures

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, complex multi-organ illness characterized by unexplained debilitating fatigue and post-exertional malaise (PEM), which is defined as a worsening of symptoms following even minor physical or mental exertion. Our study aimed to evaluate transcriptomic changes in ME/CFS female patients undergoing an exercise challenge intended to precipitate PEM.
Our time points (baseline before exercise challenge, the point of maximal exertion, and after an exercise challenge) allowed for the exploration of the transcriptomic response to exercise and recovery in female patients with ME/CFS, as compared to healthy controls (HCs). Under maximal exertion, ME/CFS patients did not show significant changes in gene expression, while HCs demonstrated altered functional gene networks related to signaling and integral functions of their immune cells.
During the recovery period (commonly during onset of PEM), female ME/CFS patients showed dysregulated immune signaling pathways and dysfunctional cellular responses to stress. The unique functional pathways identified provide a foundation for future research efforts into the disease, as well as for potential targeted treatment options.
Source: Van Booven DJ, Gamer J, Joseph A, Perez M, Zarnowski O, Pandya M, Collado F, Klimas N, Oltra E, Nathanson L. Stress-Induced Transcriptomic Changes in Females with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Reveal Disrupted Immune Signatures. International Journal of Molecular Sciences. 2023; 24(3):2698. https://doi.org/10.3390/ijms24032698 https://www.mdpi.com/1422-0067/24/3/2698 (Full text)

Lifestyle, course of COVID-19, and risk of Long-COVID in non-hospitalized patients

Abstract:

Introduction: The coronavirus disease (COVID) 2019 pandemic remains a great challenge for the healthcare system. The widely reported prolonged signs and symptoms resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (Long-COVID) require medical care. The aim of the study was to assess factors, including lifestyle variables, related to the course of COVID-19 infection and to assess their impact on prolonged symptoms in non-hospitalized patients with COVID-19.

Methods: A total of 1,847 (637 men and 1,210 women) non-hospitalized participants of the STOP-COVID registry of the PoLoCOV-Study who, following the COVID-19, underwent check-up examinations at the cardiology outpatient clinic were included in the analysis.

Results: The study participants (median age 51 [41-62] years) were evaluated at 13.4 (8.4-23.6) weeks following the diagnosis of COVID-19. Female sex (odds ratio [OR] 1.46 [95% CI 1.19-1.78]), body mass index (BMI; per 1 kg/m2: 1.02 [1.00-1.04]), hypertension (1.39 [1.07-1.81]), asthma (1.55 [1.06-2.27]), stress or overworking (1.54 [1.25-1.90]), and nightshift work (1.51 [1.06-2.14]) were independently related to the severity of symptoms during acute phase of the COVID-19 infection. The Long-COVID syndrome was independently related to the female sex (1.42 [1.13-1.79]), history of myocardial infarction (2.57 [1.04-6.32]), asthma (1.56 [1.01-2.41]), and severe course of the acute phase of the COVID-19 infection (2.27 [1.82-2.83]).

Conclusion: Female sex, BMI, asthma, hypertension, nightshifts, and stress or overworking are significantly related to the severity of the acute phase of the COVID-19 infection, while female sex, asthma, history of myocardial infarction, and the severity of symptoms in the acute phase of COVID-19 are the predictors of Long-COVID in non-hospitalized patients. We did not find an independent relation between Long-COVID and the studied lifestyle factors.

Source: Pływaczewska-Jakubowska M, Chudzik M, Babicki M, Kapusta J, Jankowski P. Lifestyle, course of COVID-19, and risk of Long-COVID in non-hospitalized patients. Front Med (Lausanne). 2022 Oct 24;9:1036556. doi: 10.3389/fmed.2022.1036556. PMID: 36353225; PMCID: PMC9637668. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9637668/ (Full text)

Effect of herbal cake-separated moxibustion on behavioral stress reactions and blood lactic acid level and muscular AMPK/PGC-1α signaling in rats with chronic fatigue syndrome

Abstract:

Objective: To observe the effect of herbal cake-separated moxibustion (HCSM) on serum lactic acid (BLA) level and AMPK/PGC-1α signaling pathway in the quadriceps femoris in chronic fatigue syndrome (CFS) rats, so as to explore its mechanisms underlying improvement of CFS.

Methods: According to the random number table, 50 SD rats were divided into blank control, model, HCSM, sham HCSM and medication (herbal medicine gavage) groups, with 10 rats in each group. The CFS model was established by using chronic restraint and exhaustive swimming, alternately, once daily for 21 days. The herbal cake was made of Xiaoyao Powder (Mental Ease Powder, composed of [Danggui (Radix Angelicae Sinensis), Baishao (Radix Paeoniae Alba), Chaihu (Radix Bupleuri), Fuling (Poria), Baizhu (Rhizoma Atractylodis, Macrocephalae), etc.]. The HCSM was applied to “Shenque” (CV8), “Guanyuan “(CV4), bilateral “Zusanli” (ST36) and “Qimen” (LR14), 5 moxa-cones for each acupoint, once daily for 10 days. For sham HCSM, the excipient was instead of herbal cake, and the same 5 moxa-cones was given as the HCSM group. Rats of the medication group received gavage of Xiaoyao Powder suspension (60 mg·kg-1), once daily for 10 days. The open field test and tail suspension test were conducted for determining the animals’ locomotor activity. The blood sample was taken from the abdominal aorta under anesthesia for assaying the levels of serum BLA, chemokine ligand CXCL9 and β-endorphin (EP) by ELISA. Bilateral quadriceps femoris were sampled for observing histopathological changes after staining with conventional H.E. technique, and for detecting the expression levels of phosphorylated AMP-activated protein kinase (p-AMPK) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) by using immunohistochemistry.

Results: Compared with the blank control group, the number of rearing and horizontal grid-crossing times, struggling times of tail suspension test were significantly decreased (P<0.05), and the immobility time was obviously prolonged (P<0.05) in the model group. Compared with the model group, both HCSM and medication groups had a significant increase of rearing, horizontal grid-crossing times and struggling times (P<0.05), and the immobility time had a significant decrease (P<0.05). But there were no significant differences in the total movement distance among the 5 groups (P>0.05), and in the 5 indexes of behavioral measurements between the HCSM and medication groups (P>0.05). The sham HCSM could also evidently increase the struggling times and reduce the immobility time (P<0.05). The contents of serum BLA, CXCL9 and β-EP were obviously higher in the model group than in the blank control group (P<0.05), as well as remarkably lower in the HCSM and medication groups than in the model group (P<0.05). Whereas the expression levels of muscular p-AMPK and PGC-1α were considerably lower in the model group than in the blank control group (P<0.05), and significantly increased in both HCSM and medication groups relevant to the model group (P<0.05). Compared with the sham HCSM group, the contents of BLA, CXCL9 and β-EP in serum of the HCSM group and contents of CXCL9, β-EP in medication group were significantly decreased (P<0.05), and the protein expressions of p-AMPK and PGC-1α in quadriceps femoris in both HCSM and medication groups were significantly increased (P<0.05). H.E. staining showed smaller intercellular space, uneven cytoplasmic staining in some muscle fibers, nucleus pyknosis and condensation, and inflammatory cell infiltration in the model group, which was milder in both HCSM and medication groups.

Conclusion: HCSM can mitigate the stress behavioral state in CFS rats, which may be related with its functions in lowering the levels of serum BLA, CXCL9 and β-EP, and activating AMPK/PGC-1α signaling pathway (balancing energy metabolism) in the quadriceps femoris.

Source: Xu XS, Ma W, Xiong LJ, Zhai CT, Li W, Tian YF. [Effect of herbal cake-separated moxibustion on behavioral stress reactions and blood lactic acid level and muscular AMPK/PGC-1α signaling in rats with chronic fatigue syndrome]. Zhen Ci Yan Jiu. 2022 Oct 25;47(10):878-84. Chinese. doi: 10.13702/j.1000-0607.20220017. PMID: 36301164. https://pubmed.ncbi.nlm.nih.gov/36301164/

Predictors of Chronic Fatigue Syndrome and Mood Disturbance After Acute Infection

Abstract:

Prospective cohort studies following individuals from acute infections have documented a prevalent post-infective fatigue state meeting diagnostic criteria for chronic fatigue syndrome (CFS) – that is, a post-infective fatigue syndrome (PIFS). The Dubbo Infection Outcomes Study (DIOS) was a prospective cohort following individuals from acute infection with Epstein-Barr virus (EBV), Ross River virus (RRV), or Q fever through to assessment of caseness for CFS designated by physician and psychiatrist assessments at 6 months. Previous studies in DIOS have revealed that functional genetic polymorphisms in both immunological (pro- and anti-inflammatory cytokines) and neurological (the purinergic receptor, P2X7) genes are associated with both the severity of the acute infection and subsequent prolonged illness.

Principal components analysis was applied to self-report data from DIOS to describe the severity and course of both the overall illness and concurrent mood disturbance. Associations between demographics and acute infection characteristics, with prolonged illness course as well as the PIFS outcome were examined using multivariable statistics. Genetic haplotype-driven functional variations in the neuropeptide Y (NPY) gene previously shown to be associated with brain responses to stress, and to trait anxiety were also examined as predictors.

The sample included 484 subjects (51% female, median age 32, IQR 19-44), of whom 90 (19%) met diagnostic criteria for CFS at 6 months. Participants with greater overall illness severity and concurrent mood disturbance in the acute illness had a more prolonged illness severity (HR = 0.39, 95% CI: 0.34-0.46, p < 0.001) and mood disturbance (HR = 0.36, 95% CI: 0.30-0.42, p < 0.001), respectively. Baseline illness severity and RRV infection were associated with delayed recovery.

Female gender and mood disturbance in the acute illness were associated with prolonged mood disturbance. Logistic regression showed that the odds of an individual being diagnosed with PIFS increased with greater baseline illness severity (OR = 2.24, 95% CI: 1.71-2.94, p < 0.001). There was no association between the NPY haplotypes with overall illness severity or mood disturbance either during the acute illness phase or with prolonged illness (p > 0.05). Severe acute infective illnesses predicted prolonged illness, prolonged mood disturbance and PIFS. These factors may facilitate early intervention to manage both PIFS and mood disturbances.

Source: Sandler CX, Cvejic E, Valencia BM, Li H, Hickie IB, Lloyd AR. Predictors of Chronic Fatigue Syndrome and Mood Disturbance After Acute Infection. Front Neurol. 2022 Jul 25;13:935442. doi: 10.3389/fneur.2022.935442. PMID: 35959390; PMCID: PMC9359311. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9359311/ (Full text)