Gynecological history in chronic fatigue syndrome: a population-based case-control study

Sex-specific clinical and neurobiological correlates of fatigue in older adults

Fatigue is a common and distressful symptom in older people and has been associated with adverse health outcomes. Nevertheless, its sex-specific pathophysiological underpinnings and clinical correlates have been scarcely investigated. We aimed to comprehensively explore the clinical and neurobiological determinants of fatigue in cognitively unimpaired older adults. A sex-stratified analysis was conducted to look for differences in the clinical expression of fatigue among women and men. Data on cognitively normal individuals were gathered from the Alzheimer's Disease Neuroimaging Initiative (ADNI) 2 study. Fatigue was defined based on self-report at baseline. For each participant, information on sociodemographics, comorbidities, mood, cognitive performance, frailty, and biomarkers of brain pathology was collected. Logistic regression models, stratified by sex, were conducted to explore the factors associated with fatigue. Among the 291 participants selected, 44 subjects (15.1% of the total sample) self-reported fatigue at baseline. Subjects reporting fatigue were more likely women, had higher frailty degrees, and more severe depressive symptoms than those without fatigue. Moreover, they tended to have lower MRI hippocampus volumes. Among women, those reporting fatigue exhibited higher frailty levels, worse depression, and lower MRI hippocampus volumes relative to those without fatigue. Higher frailty degrees were also observed in men reporting vs. non-reporting fatigue. In the adjusted logistic regression model, more severe depression (OR 1.64, 95% CI 1.18-2.28; p < 0.01) and lower MRI hippocampus volumes (OR 0.41, 95% CI 0.19-0.90; p = 0.03) resulted independently associated with fatigue in women, while higher frailty degrees (OR 3.10, 95% CI 1.27-7.54 per 0.1 increase in a 39-item Frailty index; p = 0.01) in men. Fatigue is a complex symptom with a sex-specific pattern of clinical and neurobiological correlates. A better understanding of the underlying mechanisms of these associations is warranted to develop sex-informed approaches for personalized treatments.

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties ("brain fog"), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions. Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms. Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Female reproductive health impacts of Long COVID and associated illnesses including ME/CFS, POTS, and connective tissue disorders: a literature review

Long COVID disproportionately affects premenopausal women, but relatively few studies have examined Long COVID's impact on female reproductive health. We conduct a review of the literature documenting the female reproductive health impacts of Long COVID which may include disruptions to the menstrual cycle, gonadal function, ovarian sufficiency, menopause, and fertility, as well as symptom exacerbation around menstruation. Given limited research, we also review the reproductive health impacts of overlapping and associated illnesses including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), postural orthostatic tachycardia syndrome (POTS), connective tissue disorders like Ehlers-Danlos syndrome (EDS), and endometriosis, as these illnesses may help to elucidate reproductive health conditions in Long COVID. These associated illnesses, whose patients are 70%-80% women, have increased rates of dysmenorrhea, amenorrhea, oligomenorrhea, dyspareunia, endometriosis, infertility, vulvodynia, intermenstrual bleeding, ovarian cysts, uterine fibroids and bleeding, pelvic congestion syndrome, gynecological surgeries, and adverse pregnancy complications such as preeclampsia, maternal mortality, and premature birth. Additionally, in Long COVID and associated illnesses, symptoms can be impacted by the menstrual cycle, pregnancy, and menopause. We propose priorities for future research and reproductive healthcare in Long COVID based on a review of the literature. These include screening Long COVID patients for comorbid and associated conditions; studying the impacts of the menstrual cycle, pregnancy, and menopause on symptoms and illness progression; uncovering the role of sex differences and sex hormones in Long COVID and associated illnesses; and addressing historical research and healthcare inequities that have contributed to detrimental knowledge gaps for this patient population.

The underlying sex differences in neuroendocrine adaptations relevant to Myalgic Encephalomyelitis Chronic Fatigue Syndrome

INTRODUCTION

Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) is a complex multisystem disease characterised by severe and disabling new-onset symptoms of post-exertional malaise (PEM), fatigue, brain fog, and sleep dysfunction that lasts for at least six months. Accumulating evidence suggests that sex and endocrine events have a significant influence on symptom onset and moderation of ME/CFS, with female sex being one of the most consistent and credible predictive risk factors associated with diagnosis. Such sex differences suggest sex chromosomes and sex steroids may play a part in the development of the condition or moderation of symptoms, although this has yet to be explored in detail.

METHODS/AIMS

This narrative review outlines sex differences in ME/CFS in terms of vulnerability factors and clinical phenotype and explores the known sex differences in neuroendocrine systems affected in ME/CFS and how this may relate to disease risk, onset, pathophysiology, and potential treatment avenues.

CONCLUSIONS

There is clear evidence of a sex dimorphism with regards to prevalence (3:1 female preponderance), clinical phenotypes, and aetiological triggers prior to symptom onset of ME/CFS. Endocrinological events, particularly those throughout the female lifespan, are associated with ME/CFS and include reproductive menstrual cycle fluctuations, pregnancy, post-partum and perimenopause. Further, there is evidence for gonadal sex, adrenal stress and renal neuroendocrine systems as implicated in ME/CFS, including changes in estrogen, progesterone compounds, aldosterone, and cortisol levels, of which there are established sex differences. The broad effects of steroid hormones on the physiological systems may also speak to the diversity of ME/CFS symptomatology observed in patients. Further attention must be paid to sex, age, and steroid biology in ME/CFS.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): An Overview

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic systemic disease that manifests via various symptoms such as chronic fatigue, post-exertional malaise, and cognitive impairment described as “brain fog”. These symptoms often prevent patients from keeping up their pre-disease onset lifestyle, as extended periods of physical or mental activity become almost impossible. However, the disease presents heterogeneously with varying severity across patients. Therefore, consensus criteria have been designed to provide a diagnosis based on symptoms. To date, no biomarker-based tests or diagnoses are available, since the molecular changes observed also largely differ from patient to patient. In this review, we discuss the infectious, genetic, and hormonal components that may be involved in CFS pathogenesis, we scrutinize the role of gut microbiota in disease progression, we highlight the potential of non-coding RNA (ncRNA) for the development of diagnostic tools and briefly mention the possibility of SARS-CoV-2 infection causing CFS.

The Role of Prevention in Reducing the Economic Impact of ME/CFS in Europe: A Report from the Socioeconomics Working Group of the European Network on ME/CFS (EUROMENE)

This report addresses the extent to which there may be scope for preventive programmes for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and, if so, what economic benefits may accrue from the implementation of such programmes. We consider the economic case for prevention programmes, whether there is scope for preventive programmes for ME/CFS, and what are the health and economic benefits to be derived from the implementation of such programmes. We conclude that there is little scope for primary prevention programmes, given that ME/CFS is attributable to a combination of host and environmental risk factors, with host factors appearing to be most prominent, and that there are few identified modifiable risk factors that could be the focus of such programmes. The exception is in the use of agricultural chemicals, particularly organophosphates, where there is scope for intervention, and where Europe-wide programmes of health education to encourage safe use would be beneficial. There is a need for more research on risk factors for ME/CFS to establish a basis for the development of primary prevention programmes, particularly in respect of occupational risk factors. Secondary prevention offers the greatest scope for intervention, to minimise diagnostic delays associated with prolonged illness, increased severity, and increased costs.

Endometriosis as a Comorbid Condition in Chronic Fatigue Syndrome (CFS): Secondary Analysis of Data From a CFS Case-Control Study

Background: Endometriosis (EM) is a recognized co-morbid condition in women with chronic fatigue syndrome (CFS). This analysis evaluates the impact of EM on the health of women with CFS by comparing selected health characteristics and laboratory parameters in women with CFS with and without EM (CFS+EM and CFS-only). Methods: This secondary analysis included all 36 women with CFS from a cross-sectional study of CFS in Wichita, KS, conducted between 2002 and 2003. The health characteristics and laboratory parameters of interest included functioning, fatigue, CFS-related symptoms, gynecologic history, routine laboratory parameters, inflammatory markers, cortisol levels, allostatic load, and sleep parameters (overnight polysomnography). We used parametric or non-parametric tests to compare group differences in the selected health characteristics and laboratory parameters. For examining the association between EM and variables of interest, logistic regression models were performed and odds ratios (OR) with 95% confidence intervals (CI) were reported for the magnitude of associations. Statistical significance was set at 0.05 (two-sided). Results: The mean age of this study sample was 50.9 years. Of women with CFS, 36.1% reported having EM. Age and body mass index (BMI) did not differ between CFS+EM and CFS-only groups. When examining the impact of EM, compared to women with CFS-only, women with both CFS and EM were more likely to report chronic pelvic pain [OR = 9.00 (95% CI, 1.47-55.25)] and hysterectomy [OR = 10.3 (1.82-58.39)], had more CFS symptoms (6.8 ± 0.3 vs. 5.5 ± 0.3, p = 0.02), younger mean age at menopause onset (36.4 ± 3.0 vs. 47.0 ± 2.7 years, p = 0.03), higher mean number of obstructive apnea episodes per hour (20.3 vs. 4.4, p = 0.05) and reported more negative life events (15.8 vs. 4.4, p = 0.05). Other parameters did not differ significantly between the two groups. Conclusions: We found more than a third of women with CFS reported endometriosis as a comorbid condition. The endometriosis comorbidity was associated with chronic pelvic pain, earlier menopause, hysterectomy, and more CFS-related symptoms. However, endometriosis in women with CFS did not appear to further impact functioning, fatigue, inflammatory markers, or other laboratory parameters. Further investigations including younger women are warranted.

Early menopause and other gynecologic risk indicators for chronic fatigue syndrome in women

OBJECTIVE

This study aims to examine whether gynecologic conditions are associated with chronic fatigue syndrome (CFS).

METHODS

This study includes a subset of 157 women from a population-based case-control study in Georgia, United States, conducted in 2004-2009. Gynecologic history was collected using a self-administered questionnaire. Crude odds ratios (ORs) with 95% CIs and ORs adjusted for body mass index and other covariates, where relevant, were estimated for gynecologic conditions between 84 CFS cases and 73 healthy controls.

RESULTS

Cases and controls were of similar age. Women with CFS reported significantly more gynecologic conditions and surgical operations than controls: menopause status (61.9% vs 37.0%; OR, 2.37; 95% CI, 1.21-4.66), earlier mean age at menopause onset (37.6 vs 48.6 y; adjusted OR, 1.22; 95% CI, 1.09-1.36), excessive menstrual bleeding (73.8% vs 42.5%; adjusted OR, 3.33; 95% CI, 1.66-6.70), bleeding between periods (48.8% vs 23.3%; adjusted OR, 3.31; 95% CI, 1.60-6.86), endometriosis (29.8% vs 12.3%; adjusted OR, 3.67; 95% CI, 1.53-8.84), use of noncontraceptive hormonal preparations (57.1% vs 26.0%; adjusted OR, 2.95; 95% CI, 1.36-6.38), nonmenstrual pelvic pain (26.2% vs 2.7%; adjusted OR, 11.98; 95% CI, 2.57-55.81), and gynecologic surgical operation (65.5% vs 31.5%; adjusted OR, 3.33; 95% CI, 1.66-6.67), especially hysterectomy (54.8% vs 19.2%; adjusted OR, 3.23; 95% CI, 1.46-7.17). Hysterectomy and oophorectomy occurred at a significantly younger mean age in the CFS group than in controls and occurred before CFS onset in 71% of women with records of date of surgical operation and date of CFS onset.

CONCLUSIONS

Menstrual abnormalities, endometriosis, pelvic pain, hysterectomy, and early/surgical menopause are all associated with CFS. Clinicians should be aware of the association between common gynecologic problems and CFS in women. Further work is warranted to determine whether these conditions contribute to the development and/or perpetuation of CFS in some women.

Functional somatic syndromes as risk factors for hysterectomy in early bladder pain syndrome/interstitial cystitis

OBJECTIVE

We tested the hypothesis that functional somatic syndromes (FSSs) are risk factors for hysterectomy in early bladder pain syndrome/interstitial cystitis (BPS/IC).

METHODS

In 312 women with incident BPS/IC, we diagnosed seven pre-BPS/IC syndromes: chronic pelvic pain (CPP), fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome (IBS), sicca syndrome, migraine, and panic disorder. Each was defined as present before 12 months (existing syndrome) or onset within 12 months (new syndrome) prior to BPS/IC onset. Retrospectively, we sought associations between prior hysterectomy and existing FSSs. Prospectively, we studied associations of existing and new syndromes with subsequent hysterectomy. Logistic regression analyses adjusted for age, race, menopause and education.

RESULTS

The retrospective study showed prior hysterectomy (N=63) to be associated with existing CPP and the presence of multiple existing FSSs. The prospective study revealed that 30/249 women with a uterus at baseline (12%) underwent hysterectomy in early BPS/IC. This procedure was associated with new CPP (OR 6.0; CI 2.0, 18.2), new IBS (OR 5.4; CI 1.3, 22.3), and ≥3 existing FSSs (OR 3.9; CI 1.1, 13.9).

CONCLUSION

Accounting for CPP and IBS, the presence of multiple FSSs (most without pelvic pain) was a separate, independent risk factor for hysterectomy in early BPS/IC. This suggests that patient features in addition to abdominopelvic abnormalities led to this procedure. Until other populations are assessed, a prudent approach to patients who are contemplating hysterectomy (and possibly other surgeries) for pain and who have IBS or numerous FSSs is first to try alternative therapies including treatment of the FSSs.

Gynecologic pain related to occupational stress among female factory workers in Tianjin, China

BACKGROUND

Dysmenorrhea, dyspareunia, and non-cyclic pelvic pain are health concerns for factory workers in China and may be increased by occupational stress.

OBJECTIVES

To estimate the prevalence and demographic and occupational factors associated with three types of gynecologic pain among female factory workers in Tianjin.

METHODS

The study included 651 female workers from three factories in Tianjin, China. Logistic regression models were estimated to determine associations between occupational stress and gynecologic pain.

RESULTS

Occupational stress including high job strain, exhaustion, and stress related to working conditions was a risk factor for gynecologic pain. High job strain and poor job security were associated with an increased risk for dysmenorrhea. Compulsory overtime and exhaustion were associated with increased non-cyclic pelvic pain. Working overtime and exhaustion were associated with increased dyspareunia.

CONCLUSIONS

As China's population of female factory workers grows, research on the reproductive health of this population is essential.

A role for homeostatic drive in the perpetuation of complex chronic illness: Gulf War Illness and chronic fatigue syndrome

A key component in the body's stress response, the hypothalamic-pituitary-adrenal (HPA) axis orchestrates changes across a broad range of major biological systems. Its dysfunction has been associated with numerous chronic diseases including Gulf War Illness (GWI) and chronic fatigue syndrome (CFS). Though tightly coupled with other components of endocrine and immune function, few models of HPA function account for these interactions. Here we extend conventional models of HPA function by including feed-forward and feedback interaction with sex hormone regulation and immune response. We use this multi-axis model to explore the role of homeostatic regulation in perpetuating chronic conditions, specifically GWI and CFS. An important obstacle in building these models across regulatory systems remains the scarcity of detailed human in vivo kinetic data as its collection can present significant health risks to subjects. We circumvented this using a discrete logic representation based solely on literature of physiological and biochemical connectivity to provide a qualitative description of system behavior. This connectivity model linked molecular variables across the HPA axis, hypothalamic-pituitary-gonadal (HPG) axis in men and women, as well as a simple immune network. Inclusion of these interactions produced multiple alternate homeostatic states and sexually dimorphic responses. Experimental data for endocrine-immune markers measured in male GWI subjects showed the greatest alignment with predictions of a naturally occurring alternate steady state presenting with hypercortisolism, low testosterone and a shift towards a Th1 immune response. In female CFS subjects, expression of these markers aligned with an alternate homeostatic state displaying hypocortisolism, high estradiol, and a shift towards an anti-inflammatory Th2 activation. These results support a role for homeostatic drive in perpetuating dysfunctional cortisol levels through persistent interaction with the immune system and HPG axis. Though coarse, these models may nonetheless support the design of robust treatments that might exploit these regulatory regimes.

Method Issues in Epidemiological Studies of Medically Unexplained Symptom-based Conditions in Veterans

Symptom-based conditions such as chronic fatigue syndrome (CFS) and medically unexplained multi-symptom illness (MSI) are fairly common in the general population and are also important veteran's health concerns due to their higher frequency among U.S. veterans who served during the 1990-1991 Gulf War. CFS, MSI, and other symptom-based conditions are often associated with considerable morbidity due to fatigue, chronic pain, neurologic symptoms, and other symptoms that can impair the quality of life. This article discusses several important issues of methodology that arise in population studies of CFS and MSI. These include the exclusion criteria that have been used in population studies to define CFS-like illness and unexplained MSI, the potential for false positive and false negative assessments of illness status, the potential for sex differences, and the poorly understood natural history of these symptom-based conditions across the life span. As an empirical example of these methodology issues, we examined existing data from a 2005 follow-up survey. We found that 64.9% (762 of 1,175) of female Gulf War veterans and 53.4% (2,530 of 4,739) of male Gulf War veterans had 1 or more exclusionary medical conditions. The prevalence among veterans with one or more exclusionary medical conditions increased markedly by age among females and those with a low income.

The number of existing functional somatic syndromes (FSSs) is an important risk factor for new, different FSSs

OBJECTIVE

The objective of this study is to test the hypothesis that the number of functional somatic syndromes (FSSs) predicts new, additional FSSs.

METHODS

In a recent case-control study of interstitial cystitis/painful bladder syndrome (IC/PBS), we used symptom-based consensus definitions to identify these FSSs: fibromyalgia (FM), chronic fatigue syndrome (CFS), irritable bowel syndrome (IBS), chronic pelvic pain, migraine, sicca syndrome and panic disorder. Those present before the incidence year were called antecedent FSSs; those with onset during the incidence year were called incident FSSs. In each of two groups, 312 IC/PBS cases and 313 controls, rates of incident FSSs were compared among those with 0, 1, 2, or ≥3 antecedent FSSs. Confounding was assessed using logistic regression analyses that included the individual antecedent FSSs, published correlates of these FSSs, and demographic variables.

RESULTS

The incidence of a new FSS increased with the number of antecedent FSSs, as did that of incident FM, CFS and IBS studied separately. These findings were not confounded by other variables. The presence of multiple antecedent FSSs generally had the highest odds ratio for new, different, incident FSSs.

CONCLUSIONS

This study revealed that the number of antecedent FSSs was among the strongest risk factors for other FSSs, especially incident FM, CFS and IBS. This suggests that the FSSs are linked through a polysyndromic phenotype. If each FSS is heterogeneous, to seek a pathogenesis common to all FSSs, individuals with multiple FSSs should be sought; to seek a pathogenesis unique to a specific FSS, mature persons who have only that FSS should be studied.

Overlap between functional GI disorders and other functional syndromes: what are the underlying mechanisms?

BACKGROUND

Irritable bowel syndrome and other gastrointestinal (GI) and non-GI disorders such as functional dyspepsia, fibromyalgia, temporomandibular joint disorder, interstitial cystitis/painful bladder syndrome, and chronic fatigue syndrome are known as functional pain syndromes. They commonly coexist within the same individual. The pathophysiologic mechanisms of these disorders are not well understood, but it has been hypothesized that they share a common pathogenesis.

PURPOSE

The objective of this review is to discuss the proposed pathophysiologic mechanisms, which have been similarly studied in these conditions. These mechanisms include enhanced pain perception, altered regional brain activation, infectious etiologies, dysregulations in immune and neuroendocrine function, and genetic susceptibility. Studies suggest that these functional disorders are multifactorial, but factors which increase the vulnerability of developing these conditions are shared.