COVID-19 and Chronic Fatigue Syndrome: An Endocrine Perspective

Abstract:

Patients recovering from COVID-19 may have persistent debilitating symptoms requiring long term support through individually tailored cardiopulmonary and psychological rehabilitation programs. Clinicians need to be aware about the likely long-term complications and their diagnostic assessments to help identify any occult problems requiring additional help. Endocrinological evaluations should be considered as part of the armamentarium in the management of such individuals with diligent cognizance about the involvement of the hypothalamo-pituitary-adrenal (HPA) axis, adrenals, and thyroid.

Source: Bansal R, Gubbi S, Koch CA. COVID-19 and Chronic Fatigue Syndrome: An Endocrine Perspective. J Clin Transl Endocrinol. 2021 Dec 3:100284. doi: 10.1016/j.jcte.2021.100284. Epub ahead of print. PMID: 34877261; PMCID: PMC8641402. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8641402/ (Full text)

Hypothalamic-Pituitary autoimmunity and related impairment of hormone secretions in chronic fatigue syndrome

Abstract:

Context: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe chronic illness which reduces the quality of life. A potential role of neuroendocrine autoimmune dysfunction has been hypothesized.

Objective: To investigate the occurrence of anti-pituitary (APA) and anti-hypothalamic (AHA) antibodies and possible related hypothalamic/pituitary dysfunctions in ME/CSF patients.

Design, setting, patients and other participants: This is a case-control study conducted in University Hospital setting (Stanford, Naples). Thirty women with ME/CSF (Group 1) diagnosed according to Fukuda, Canadian, and IOM criteria, at Stanford University, were enrolled and compared with 25 age-matched healthy controls.

Main outcome measures: APA and AHA were detected by immunofluorescence; moreover, we investigated hormonal secretions of anterior pituitary and respective target glands and plasma and urinary osmolality. Both APA and AHA titers were assessed and the prevalence of pituitary hormone deficiencies was also investigated.

Results: Patients in Group 1 showed a high prevalence of AHA (33%) and APA (56%) and a significant lower levels of ACTH/cortisol, and GH peak/IGF1 vs controls (all AHA/APA negative). Patients in Group 1A (13 patients positive at high titers, ≥1:32) showed ACTH/cortisol and GH peak/ IGF1 levels significantly lower and more severe forms of ME/CFS with respect to patients in Group 1B (7 positive at middle/low titers,1:16-1:8) and 1C (10 Ab negative patients).

Conclusions: Both AHA and/or APA at high titers associated with hypothalamic/pituitary dysfunction suggest that hypothalamic/pituitary autoimmunity may play an important role in the manifestations of ME/CFS, especially in its more severe forms.

Source: De Bellis A, Bellastella G, Pernice V, Cirillo P, Longo M, Maio A, Scappaticcio L, Maiorino MI, Bellastella A, Esposito K, Montoya JG. Hypothalamic-Pituitary autoimmunity and related impairment of hormone secretions in chronic fatigue syndrome. J Clin Endocrinol Metab. 2021 Jul 13:dgab429. doi: 10.1210/clinem/dgab429. Epub ahead of print. PMID: 34254637. https://pubmed.ncbi.nlm.nih.gov/34254637/

Neuroinflammation disorders exacerbated by environmental stressors

Abstract:

Neuroinflammation is a condition characterized by the elaboration of proinflammatory mediators within the central nervous system. Neuroinflammation has emerged as a dominant theme in contemporary neuroscience due to its association with neurodegenerative disease states such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease.

While neuroinflammation often is associated with damage to the CNS, it also can occur in the absence of neurodegeneration, e.g., in association with systemic infection. The “acute phase” inflammatory response to tissue injury or infections instigates neuroinflammation-driven “sickness behavior,” i.e. a constellation of symptoms characterized by loss of appetite, fever, muscle pain, fatigue and cognitive problems. Typically, sickness behavior accompanies an inflammatory response that resolves quickly and serves to restore the body to homeostasis. However, recurring and sometimes chronic sickness behavior disorders can occur in the absence of an underlying cause or attendant neuropathology.

Here, we review myalgic enchepalomyelitis/chronic fatigue syndrome (ME/CFS), Gulf War Illness (GWI), and chemobrain as examples of such disorders and propose that they can be exacerbated and perhaps initiated by a variety of environmental stressors. Diverse environmental stressors may disrupt the hypothalamic pituitary adrenal (HPA) axis and contribute to the degree and duration of a variety of neuroinflammation-driven diseases.

Source: O’Callaghan JP, Miller DB. Neuroinflammation disorders exacerbated by environmental stressors. Metabolism. 2019 Nov;100S:153951. doi: 10.1016/j.metabol.2019.153951. https://www.ncbi.nlm.nih.gov/pubmed/31610852

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown aetiology that is recognized by the World Health Organization (WHO) and the United States Center for Disease Control and Prevention (US CDC) as a disorder of the brain. The disease predominantly affects adults, with a peak age of onset of between 20 and 45 years with a female to male ratio of 3:1. Although the clinical features of the disease have been well established within diagnostic criteria, the diagnosis of ME/CFS is still of exclusion, meaning that other medical conditions must be ruled out.

The pathophysiological mechanisms are unclear but the neuro-immuno-endocrinological pattern of CFS patients gleaned from various studies indicates that these three pillars may be the key point to understand the complexity of the disease. At the moment, there are no specific pharmacological therapies to treat the disease, but several studies’ aims and therapeutic approaches have been described in order to benefit patients’ prognosis, symptomatology relief, and the recovery of pre-existing function.

This review presents a pathophysiological approach to understanding the essential concepts of ME/CFS, with an emphasis on the population, clinical, and genetic concepts associated with ME/CFS.

Source: Cortes Rivera M, Mastronardi C, Silva-Aldana CT, Arcos-Burgos M, Lidbury BA. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review. Diagnostics (Basel). 2019 Aug 7;9(3). pii: E91. doi: 10.3390/diagnostics9030091. https://www.ncbi.nlm.nih.gov/pubmed/31394725

High-fidelity discrete modeling of the HPA axis: a study of regulatory plasticity in biology

Abstract:

BACKGROUND: The hypothalamic-pituitary-adrenal (HPA) axis is a central regulator of stress response and its dysfunction has been associated with a broad range of complex illnesses including Gulf War Illness (GWI) and Chronic Fatigue Syndrome (CFS). Though classical mathematical approaches have been used to model HPA function in isolation, its broad regulatory interactions with immune and central nervous function are such that the biological fidelity of simulations is undermined by the limited availability of reliable parameter estimates.

METHOD: Here we introduce and apply a generalized discrete formalism to recover multiple stable regulatory programs of the HPA axis using little more than connectivity between physiological components. This simple discrete model captures cyclic attractors such as the circadian rhythm by applying generic constraints to a minimal parameter set; this is distinct from Ordinary Differential Equation (ODE) models, which require broad and precise parameter sets. Parameter tuning is accomplished by decomposition of the overall regulatory network into isolated sub-networks that support cyclic attractors. Network behavior is simulated using a novel asynchronous updating scheme that enforces priority with memory within and between physiological compartments.

RESULTS: Consistent with much more complex conventional models of the HPA axis, this parsimonious framework supports two cyclic attractors, governed by higher and lower levels of cortisol respectively. Importantly, results suggest that stress may remodel the stability landscape of this system, favoring migration from one stable circadian cycle to the other. Access to each regime is dependent on HPA axis tone, captured here by the tunable parameters of the multi-valued logic. Likewise, an idealized glucocorticoid receptor blocker alters the regulatory topology such that maintenance of persistently low cortisol levels is rendered unstable, favoring a return to normal circadian oscillation in both cortisol and glucocorticoid receptor expression.

CONCLUSION: These results emphasize the significance of regulatory connectivity alone and how regulatory plasticity may be explored using simple discrete logic and minimal data compared to conventional methods.

Source: Sedghamiz H, Morris M, Craddock TJA, Whitley D, Broderick G. High-fidelity discrete modeling of the HPA axis: a study of regulatory plasticity in biology. BMC Syst Biol. 2018 Jul 17;12(1):76. doi: 10.1186/s12918-018-0599-1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6050677/ (Full article)

Hair and salivary cortisol in a cohort of women with chronic fatigue syndrome

Abstract:

Hypocortisolism has been found in CFS patients in blood, urine, and saliva. It is unclear if hypocortisolism can also be demonstrated using long-term cortisol measurements, such as cortisol in hair. In addition, the interaction between the HPA axis and the immune system, both expected to play an important role in CFS, is unclear. The objective of the current study was to compare hair and salivary cortisol concentrations in a cohort of female CFS patients to those in healthy controls, and to test the effect of an interleukin-1 receptor antagonist (anakinra) on the HPA axis.

Salivary cortisol concentrations of 107 CFS patients were compared to 59 healthy controls, with CFS patients showing a decreased cortisol awakening response (4.2 nmol/L ± 5.4 vs 6.1 nmol/L ± 6.3, p = 0.036). Total cortisol output during the day did not differ significantly in saliva, but there was a trend to lower hair cortisol in a subset of 46 patients compared to 46 controls (3.8 pg/mg ± 2.1 vs 4.3 pg/mg ± 1.8, p = 0.062). After four weeks of treatment with either daily anakinra (100 mg/day) or placebo, there was a slight decrease of hair cortisol concentrations in the anakinra group compared to an increase in the placebo group (p = 0.022). This study confirms the altered dynamics of the HPA axis in a group of CFS patients, and for the first time shows that this might also be present for long-term cortisol measures.

Source: Roerink ME, Roerink SHPP, Skoluda N, van der Schaaf ME, Hermus ARMM, van der Meer JWM, Knoop H, Nater UM. Hair and salivary cortisol in a cohort of women with chronic fatigue syndrome. Horm Behav. 2018 May 25. pii: S0018-506X(17)30569-X. doi: 10.1016/j.yhbeh.2018.05.016. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29807037

Neuroendocrine disorder in chronic fatigue syndrome

Abstract:

Background/aim: Neuroendocrine disorders are considered a possible pathogenetic mechanism in chronic fatigue syndrome (CFS). The aim of our study was to determine the function of the hypothalamic-pituitary-adrenal axis (HPA) and thyroid function in women of reproductive age suffering from CFS.

Materials and methods: The study included 40 women suffering from CFS and 40 healthy women (15-45 years old). Serum levels of cortisol (0800 and 1800 hours), ACTH, total T4, total T3, and TSH were measured in all subjects. The Fibro Fatigue Scale was used for determination of fatigue level.

Results: Cortisol serum levels were normal in both groups. The distinctively positive moderate correlation of morning and afternoon cortisol levels that was observed in healthy women was absent in the CFS group. This may indicate a disturbed physiological rhythm of cortisol secretion. Although basal serum T4, T3, and TSH levels were normal in all subjects, concentrations of T3 were significantly lower in the CFS group.

Conclusion: One-time hormone measurement is not sufficient to detect hormonal imbalance in women suffering from CFS. Absence of a correlation between afternoon and morning cortisol level could be a more representative factor for detecting HPA axis disturbance.

Source: Tomic S, Brkic S, Lendak D, Maric D, Medic Stojanoska M, Novakov Mikic A. Neuroendocrine disorder in chronic fatigue syndrome. Turk J Med Sci. 2017 Aug 23;47(4):1097-1103. doi: 10.3906/sag-1601-110. https://www.ncbi.nlm.nih.gov/pubmed/29154201

Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival

Abstract:

Background: Chronic fatigue syndrome (CFS) is a prevalent and disabling condition affecting adolescents. The pathophysiology is poorly understood, but immune alterations might be an important component. This study compared whole blood gene expression in adolescent CFS patients and healthy controls, and explored associations between gene expression and neuroendocrine markers, immune markers and clinical markers within the CFS group.

Methods: CFS patients (12–18 years old) were recruited nation-wide to a single referral center as part of the NorCAPITAL project. A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls having comparable distribution of gender and age were recruited from local schools. Whole blood samples were subjected to RNA sequencing. Immune markers were blood leukocyte counts, plasma cytokines, serum C-reactive protein and immunoglobulins. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings.

Results: A total of 29 CFS patients and 18 healthy controls were included. We identified 176 genes as differentially expressed in patients compared to controls, adjusting for age and gender factors. Gene set enrichment analyses suggested impairment of B cell differentiation and survival, as well as enhancement of innate antiviral responses and inflammation in the CFS group. A pattern of co-expression could be identified, and this pattern, as well as single gene transcripts, was significantly associated with indices of autonomic nervous activity, plasma cortisol, and blood monocyte and eosinophil counts. Also, an association with symptoms of post-exertional malaise was demonstrated.

Conclusion: Adolescent CFS is characterized by differential gene expression pattern in whole blood suggestive of impaired B cell differentiation and survival, and enhanced innate antiviral responses and inflammation. This expression pattern is associated with neuroendocrine markers of altered HPA axis and autonomic nervous activity, and with symptoms of post-exertional malaise.

Trial registration Clinical Trials NCT01040429

Source: Chinh Bkrong Nguyen, Lene Alsøe, Jessica M. Lindvall, Dag Sulheim, Even Fagermoen, Anette Winger, Mari Kaarbø, Hilde Nilsen and Vegard Bruun Wyller. Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival. Journal of Translational Medicine 2017 15:102. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1201-0 (Full article)

Chronic Fatigue Syndrome Linked To Impaired Stress Response

Subtle alterations of a hormonal stress response system called the HPA axis may play a role in chronic fatigue syndrome, according to a study in the November/December issue of Psychosomatic Medicine.

A smoothly functioning hypothalamus-pituitary-adrenal, or HPA, axis helps the body remain stable under physiological and psychological stress through the actions of three hormones. First, the brain portion called the hypothalamus secretes a hormone that stimulates the pituitary gland to secrete a second hormone. This second hormone causes the adrenal glands to create cortisol.

Problems can occur at any point in this process and result in a variety of diseases. A research team led by Jens Gaab, Ph.D., of the Center for Psychobiological and Psychosomatic Research at the University of Trier in Trier, Germany; and the Institute of Psychology at the University of Zürich in Switzerland are proposing that chronic fatigue syndrome may be one of them.

Chronic fatigue syndrome is characterized by debilitating fatigue that can include including muscle aches, low-grade fever and sleep disturbances. Its cause is not understood.

Gaab and colleagues recruited approximately 40 study participants between the ages of 30 and 50. Half of the participants were chronic fatigue sufferers and the other half were healthy volunteers. All participants completed questionnaires measuring fatigue, depression and coping skills.

To examine the HPA axis in action, participants were given blood, cardiovascular and saliva tests before and after taking two stress tests. The first, a psychosocial stress test, involved preparing for a fake job interview and completing an arithmetic problem before an audience while under the impression they were being videotaped. The second test measured physical stress on a stationary bicycle.

Participants were also given a series of insulin injections known as the insulin tolerance test. “The ITT is considered the gold standard for testing the integrity of the entire HPA axis,” Gaab says.

The researchers found significantly lower response levels of one of the HPA hormones, called ACTH, among the chronic fatigue patients compared with the healthy volunteers, during both stress tests as well as the ITT test. In fact, the chronic fatigue patients had significantly lower levels of the hormone before the testing even began.

“These results suggest that on a central level, subtle dysregulations of the HPA axis exist” in chronic fatigue syndrome patients, Gaab says, adding that future studies should include repeated evaluation of the HPA axis over the course of the syndrome.

Gaab and colleagues note that the possible role of cortisol in chronic fatigue syndrome still merits investigation, as low doses of hydrocortisone have shown some positive results in chronic fatigue patients.

Source: Center For The Advancement Of Health. “Chronic Fatigue Syndrome Linked To Impaired Stress Response.” ScienceDaily. ScienceDaily, 27 November 2002. https://www.sciencedaily.com/releases/2002/11/021126202215.htm

Epigenetic modifications and glucocorticoid sensitivity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

BACKGROUND: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating idiopathic disease characterized by unexplained fatigue that fails to resolve with sufficient rest. Diagnosis is based on a list of symptoms and exclusion of other fatigue-related health conditions. Despite a heterogeneous patient population, immune and hypothalamic-pituitary-adrenal (HPA) axis function differences, such as enhanced negative feedback to glucocorticoids, are recurring findings in ME/CFS studies. Epigenetic modifications, such as CpG methylation, are known to regulate long-term phenotypic differences and previous work by our group found DNA methylome differences in ME/CFS, however the relationship between DNA methylome modifications, clinical and functional characteristics associated with ME/CFS has not been examined.

METHODS: We examined the DNA methylome in peripheral blood mononuclear cells (PBMCs) of a larger cohort of female ME/CFS patients using the Illumina HumanMethylation450 BeadChip Array. In parallel to the DNA methylome analysis, we investigated in vitro glucocorticoid sensitivity differences by stimulating PBMCs with phytohaemagglutinin and suppressed growth with dexamethasone. We explored DNA methylation differences using bisulfite pyrosequencing and statistical permutation. Linear regression was implemented to discover epigenomic regions associated with self-reported quality of life and network analysis of gene ontology terms to biologically contextualize results.

RESULTS: We detected 12,608 differentially methylated sites between ME/CFS patients and healthy controls predominantly localized to cellular metabolism genes, some of which were also related to self-reported quality of life health scores. Among ME/CFS patients, glucocorticoid sensitivity was associated with differential methylation at 13 loci.

CONCLUSIONS: Our results indicate DNA methylation modifications in cellular metabolism in ME/CFS despite a heterogeneous patient population, implicating these processes in immune and HPA axis dysfunction in ME/CFS. Modifications to epigenetic loci associated with differences in glucocorticoid sensitivity may be important as biomarkers for future clinical testing. Overall, these findings align with recent ME/CFS work that point towards impairment in cellular energy production in this patient population.

 

Source: de Vega WC, Herrera S, Vernon SD, McGowan PO. Epigenetic modifications and glucocorticoid sensitivity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). BMC Med Genomics. 2017 Feb 23;10(1):11. doi: 10.1186/s12920-017-0248-3. https://www.ncbi.nlm.nih.gov/pubmed/28231836