HPA axis reactivity and lymphocyte glucocorticoid sensitivity in fibromyalgia syndrome and chronic pelvic pain

Changes in biochemical markers following a spinal manipulation - a systematic review update

OBJECTIVE

The aim of this systematic review was to update the current level of evidence for spinal manipulation in influencing various biochemical markers in healthy and/or symptomatic population.

METHODS

This is a systematic review update. Various databases were searched (inception till May 2023) and fifteen trials (737 participants) that met the inclusion criteria were included in the review. Two authors independently screened, extracted and assessed the risk of bias in included studies. Outcome measure data were synthesized using standard mean differences and meta-analysis for the primary outcome (biochemical markers). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the quality of the body of evidence for each outcome of interest.

RESULTS

There was low-quality evidence that spinal manipulation influenced various biochemical markers (not pooled). There was low-quality evidence of significant difference that spinal manipulation is better (SMD -0.42, 95% CI - 0.74 to -0.1) than control in eliciting changes in cortisol levels immediately after intervention. Low-quality evidence further indicated (not pooled) that spinal manipulation can influence inflammatory markers such as interleukins levels post-intervention. There was also very low-quality evidence that spinal manipulation does not influence substance-P, neurotensin, oxytocin, orexin-A, testosterone and epinephrine/nor-epinephrine.

CONCLUSION

Spinal manipulation may influence inflammatory and cortisol post-intervention. However, the wider prediction intervals in most outcome measures point to the need for future research to clarify and establish the clinical relevance of these changes.

Melatonin as a Coadjuvant in the Treatment of Patients with Fibromyalgia

Fibromyalgia syndrome (FMS) is a chronic widespread pain syndrome that is accompanied by fatigue, sleep disturbances, anxiety, depression, lack of concentration, and neurocognitive impairment. As the currently available drugs are not completely successful against these symptoms and frequently have several side effects, many scientists have taken on the task of looking for nonpharmacological remedies. Many of the FMS-related symptoms have been suggested to be associated with an altered pattern of endogenous melatonin. Melatonin is involved in the regulation of several physiological processes, including circadian rhythms, pain, mood, and oxidative as well as immunomodulatory balance. Preliminary clinical studies have propounded that the administration of different doses of melatonin to patients with FMS can reduce pain levels and ameliorate mood and sleep disturbances. Moreover, the total antioxidant capacity, 6-sulfatoxymelatonin and urinary cortisol levels, and other biological parameters improve after the ingestion of melatonin. Recent investigations have proposed a pathophysiological relationship between mitochondrial dysfunction, oxidative stress, and FMS by looking at certain proteins involved in mitochondrial homeostasis according to the etiopathogenesis of this syndrome. These improvements exert positive effects on the quality of life of FMS patients, suggesting that the use of melatonin as a coadjuvant may be a successful strategy for the management of this syndrome.

Higher self-perceived stress reactivity is associated with increased chronic pain risk

Self-perceived stress reactivity—how a person cognitively and emotionally responds to a stressor—is longitudinally associated with increased odds for the development of chronic pain.

Introduction:

Experiencing stress can contribute to unfavorable pain experiences, but outcomes vary across individuals. Evidence suggests that a person's specific reactivity to stressful events may influence pain responses. Previous studies measuring physiological stress reactivity have found associations with pain both clinically and in the laboratory. However, the time and cost required for testing physiological stress reactivity may limit clinical application.

Objective:

Self-reported perception of one's own stress reactivity has been shown to correlate with physiological stress reactivity in relation to health outcomes and may represent a valuable tool in clinical pain assessment.

Methods:

Using data from the Midlife in the US survey, we selected participants who did not have chronic pain at baseline (n = 1512) and who had data at follow-up 9 years later. Stress reactivity was assessed using a subscale of the Multidimensional Personality Questionnaire. We conducted a binary logistic regression to determine the odds of developing chronic pain, controlling for demographics and other health-related variables.

Results:

Results indicate that higher reported stress reactivity at baseline increased the odds of developing chronic pain at follow-up (odds ratio (OR) = 1.085, 95% confidence interval (CI) (1.021, 1.153), P = 0.008), with the only other significant predictor being the number of chronic conditions (OR = 1.118, 95% CI (1.045, 1.197), P = 0.001).

Conclusion:

Findings provide evidence for the predictive criterion validity of self-reported stress reactivity in the context of chronic pain risk. More generally, with increased need for virtual assessment and care, self-reported stress reactivity may be a useful, time-efficient, and cost-efficient tool for predicting pain outcomes in research and clinical contexts.

Physiological reactions to acute stressors and subjective stress during daily life: A systematic review on ecological momentary assessment (EMA) studies

OBJECTIVE

This review aims to provide an overview of ecological momentary assessment (EMA) studies analyzing stress reactivity during daily life in terms of direct and moderated influence of acute stress on physiological responses.

MATERIALS AND METHODS

A systematic literature search was performed on November 29, 2021 using Web of Science, MEDLINE and PsycINFO to identify prospective EMA studies targeting acute stressors or stress under naturalistic conditions, without restrictions of publication date or population. Study quality was assessed for multiple EMA-specific sources of bias.

RESULTS

Out of 4285 non-duplicate records, 107 publications involving 104 unique studies were included. The majority of studies assessed acute physiological stress responses primarily through salivary cortisol (n = 59) and cardiovascular outcomes (n = 32). Most studies performed at least three measurements per day (n = 59), and had a moderate risk of recall bias (n = 68) and confounding (n = 85). Fifty-four studies reported a compliance of ≥80%. Direct, non-moderated positive associations were observed between acute stress exposure and concurrent cortisol levels (44%, n = 11/25), systolic (44%, 8/18) and diastolic blood pressure (53%, 8/15) and heart rate (53%, 9/17). Several inter- and intra-individual moderators were identified, such as age, gender, health status, chronic stress, work-related resources, physical activity and stress coping indicators.

CONCLUSIONS

About half of the reviewed EMA studies demonstrated direct associations between everyday acute stress exposure and physiological responses, including increased cortisol levels, blood pressure and heart rate. Results further suggested various moderator variables that could help develop tailored prevention strategies and identify groups at higher risk for dysfunctional stress responses.

REGISTRATION

PROSPERO-Reg.-No.: PROSPERO 2020 CRD42020163178.

Alterations of monoamine neurotransmitters, HPA-axis hormones, and inflammation cytokines in reserpine-induced hyperalgesia and depression comorbidity rat model

BACKGROUND

Pain and depression often occur simultaneously, but the mechanism of this condition is still unclear.

METHODS

The aim of this study was to examine the alterations of monoamine neurotransmitters, hypothalamic-pituitary-adrenal (HPA) axis hormones, and inflammation cytokines in hyperalgesia and depression comorbidities. The reserpine-induced "Sprague Dawley" (SD) rat models were used, and the concentrations of monoamine neurotransmitters serotonin (5-HT), norepinephrine (NE), dopamine (DA), and their metabolic products 5-hydroxyindoleacetic acid (5-HIAA), Homovanillic acid (HVA), 3,4-Dihydroxyphenylacetic acid (DOPAC) in raphe nucleus region were tested by High Performance Liquid Chromatography (HPLC). Serum levels of Adrenocorticotropic Hormone (ACTH), Cortisol (CORT), and inflammatory cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-4, IL-10 were assessed by enzyme linked immunosorbent assay.

RESULTS

Repeated reserpine injection induced hyperalgesia and depressive behaviors with decreased sucrose preference and horizontal movement distance, and increased immobility time in forced swimming test. The concentrations of 5-HT and NE in raphe nucleus, and ACTH and CORT in serum were elevated in the model group. And the model group showed increases in serum IL-1β and IL-6, and decrease in serum IL-10.

CONCLUSION

More research in these areas is needed to understand the pathogenesis of the disease, so as to find more and better therapeutic targets.

Blunted Pain Modulation Response to Induced Stress in Women with Fibromyalgia with and without Posttraumatic Stress Disorder Comorbidity: New Evidence of Hypo-Reactivity to Stress in Fibromyalgia?

There is evidence regarding the presence of alterations in both the stress response and the endogenous pain modulation systems of people with fibromyalgia (FM). However, research on pain modulation under induced stress on FM patients is scarce and contradictory. The present study analyzes stress-induced changes in pain and intolerance thresholds among FM patients, examining the possible existence of differences linked to PTSD comorbidity and gaining insights into the role of cardiovascular reactivity. Eighteen women diagnosed with FM and comorbid PTSD (FM + PTSD), 18 women diagnosed with FM and no PTSD (FM-PTSD), and 38 healthy women (HC) were exposed to the Social Stress Test task. Pressure pain thresholds and intolerance thresholds were measured before and during stress induction, and after a recovery period, while systolic blood pressure and heart rate were simultaneously recorded. Overall, while pain thresholds decreased during stress and recovery for HC, no significant changes were observed for women with FM. The intolerance threshold decreased for HC during stress, but was maintained at basal level during recovery. FM-PTSD women exhibited a delayed response, with a drop at recovery. For FM + PTSD, tolerance levels remained unchanged. In addition, cardiovascular reactivity did not seem to explain these results. This performance of the pain modulation system seems to follow the same pattern of hypoactive responsiveness under stressors that has previously been observed in FM patients on the autonomic and neuroendocrine axes. Such a hypoactive pattern may involve a non-adaptive response that may contribute to the development and maintenance of chronic pain.

Posttraumatic Stress Disorder and Persistent Somatic Symptoms During the COVID-19 Pandemic: The Role of Sense of Threat

OBJECTIVE

Persistent somatic symptoms, such as pain and fatigue, have been referred to as somatization. Somatization is commonly associated with histories of trauma and posttraumatic stress disorder (PTSD). Although previous research has demonstrated that PTSD can predict somatic problems, there has been no examination of this at the level of PTSD symptom clusters and multidimensional assessment of somatic symptoms. We examined the association between the three International Classification of Disease (11th Edition) PTSD symptom clusters (reexperiencing in the here and now, avoidance, and sense of threat), measured in relation to the COVID-19 pandemic as the stressor, and somatic symptoms while statistically adjusting for confounding variables.

METHODS

Participants were a nationally representative sample of 1041 adults from the general population of the Republic of Ireland. Physical health problems across the domains of pain, gastrointestinal, cardiopulmonary, and fatigue were assessed by the Patient Health Questionnaire, and PTSD symptoms were assessed using the International Trauma Questionnaire.

RESULTS

Sense of threat was associated with the presence of pain (β = 0.254), fatigue (β = 0.332), gastrointestinal (β = 0.234), and cardiovascular symptoms (β = 0.239). Avoidance was associated with pain (β = 0.347). Reexperiencing was not associated with any physical health variable.

CONCLUSIONS

In the context of COVID-19, the sense of threat symptoms in PTSD is most strongly related to somatic problems. Findings suggest that interventions addressing sense of threat symptoms might provide relief from somatization.

Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update

Fibromyalgia is a syndrome characterized by chronic and widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue, intestinal disorders and alterations in sleep and mood. It is estimated that two to eight percent of the world population is affected by fibromyalgia. From a medical point of view, this pathology still presents inexplicable aspects. It is known that fibromyalgia is caused by a central sensitization phenomenon characterized by the dysfunction of neuro-circuits, which involves the perception, transmission and processing of afferent nociceptive stimuli, with the prevalent manifestation of pain at the level of the locomotor system. In recent years, the pathogenesis of fibromyalgia has also been linked to other factors, such as inflammatory, immune, endocrine, genetic and psychosocial factors. A rheumatologist typically makes a diagnosis of fibromyalgia when the patient describes a history of pain spreading in all quadrants of the body for at least three months and when pain is caused by digital pressure in at least 11 out of 18 allogenic points, called tender points. Fibromyalgia does not involve organic damage, and several diagnostic approaches have been developed in recent years, including the analysis of genetic, epigenetic and serological biomarkers. Symptoms often begin after physical or emotional trauma, but in many cases, there appears to be no obvious trigger. Women are more prone to developing the disease than men. Unfortunately, the conventional medical therapies that target this pathology produce limited benefits. They remain largely pharmacological in nature and tend to treat the symptomatic aspects of various disorders reported by the patient. The statistics, however, highlight the fact that 90% of people with fibromyalgia also turn to complementary medicine to manage their symptoms.

Application of Salivary Biomarkers in the Diagnosis of Fibromyalgia

Fibromyalgia (FM) is a highly prevalent syndrome that impairs the quality of life of the patients; however, its diagnosis is complex and mainly centered on pain symptoms. The study of salivary biomarkers has proven highly useful for the diagnosis and prognosis of numerous diseases. The objective of this review was to gather published data on the utilization of salivary biomarkers to facilitate and complement the diagnosis of FM. Salivary biomarkers used in FM diagnosis include cortisol; calgranulin; and the enzymes α-amylase, transaldolase, and phosphoglycerate mutase. Increased serum levels of C-reactive protein, cytokines interleukin 1-β, interleukin 6, interleukin 8, interleukin 10, interleukin 17, tumor necrosis factor α, and various chemokines may serve as salivary biomarkers, given observations of their increased serum levels in patients with FM. Further research is warranted to study in depth the role and performance of biomarkers currently used in FM diagnosis/prognosis and to identify novel salivary biomarkers for this disease.

Hypothalamic-Pituitary-Adrenal Axis Responses in Women with Endometriosis-Related Chronic Pelvic Pain

Some chronic pain conditions and comorbidities suppress the hypothalamic-pituitary-adrenal (HPA) axis and response to dynamic testing. We measured HPA axis responses to corticotropin-releasing hormone (CRH) administration in relation to chronic pelvic pain and endometriosis. In a cross-sectional study of women (n = 54) with endometriosis-associated chronic pelvic pain (n = 22), chronic pelvic pain alone (n = 12), or healthy volunteers (n = 20), adrenocorticotropic-releasing hormone (ACTH) and cortisol levels were measured at 0, 15, 30, and 45 min after intravenous ovine CRH administration. ACTH and cortisol delta (peak-baseline) and area under the curve (AUC) were compared by study group and assessed for association with race and menstrual and non-menstrual pain severity. HPA axis responses did not differ among the racially diverse groups or in those with pain compared with healthy volunteers. However, when stratified by race, ACTH delta (129.9 ± 130.7 vs. 52.5 ± 66.0 pg/mL; p = 0.003), ACTH AUC (4813 ± 4707 vs. 2290 ± 2900 min*pg/mL; p = 0.013), and cortisol delta (26.3 ± 21.5 vs. 13.2 ± 9.7 μg/mL; p = 0.005) were significantly higher in black (n = 10) than predominately white (non-black) subjects (n = 44; 39/44 white). In analyses among primarily white (non-black) women, greater menstrual pain severity was associated with blunted ACTH delta (p = 0.015) and cortisol delta (p = 0.023), and greater non-menstrual pain severity with blunted cortisol delta (p = 0.017). Neuroendocrine abnormalities in women with chronic pelvic pain may differ by pain manifestations and may vary by race. The higher HPA axis response in black women merits investigation in pelvic pain studies stratified by race. In white (non-black) women experiencing pain, a blunted response was related to pain severity suggesting pain affects women independently of endometriosis lesions.

Central Nervous System Changes in Pelvic Inflammation/Pain Patients

Purpose of Review

Centralized pain syndromes (CPS), including chronic pelvic pain (CPP) syndrome, are significant public health problems with prevalence more than diabetes, cancer, or cardiovascular disease. A variety of pathologies are linked with CPP syndrome; however, pain often continues without the presence of pathology, or when an underlying pelvic disease is found, the extent and severity of pain are disproportionate. Although this is not a systematic review, we performed a detailed literature search to identify relevant papers and to provide the available evidence for central changes in association with CPP syndrome.

Recent Findings

Recent advances in brain imaging techniques have provided more accurate data on gray matter volume, functional connectivity, and metabolite levels in the pain-relevant areas of the brain. The present evidence shows that like other chronic pain conditions, the CPP syndrome is associated with central nervous system (CNS) alterations. In particular, these include changes in brain structure, in the activity of both the hypothalamic–pituitary–adrenal (HPA) axis and the autonomic nervous system, and in the behavioral and central response to noxious stimulation.

Summary

A growing body of evidence, mostly from neuroimaging, suggests that for many patients with CPP, the pain may be associated to changes in both structure and function of the CNS. The treatment of pain symptoms, even without the presence of identifiable pathology, may prevent the development or at least minimize the progression of long-term central changes. These findings support the use of new therapeutic strategies targeting the CNS for controlling of pain in CPP conditions.

Transitioning from acute to chronic pain: a simulation study of trajectories of low back pain

Background

Identifying how pain transitions from acute to chronic is critical in designing effective prevention and management techniques for patients’ well-being, physically, psychosocially, and financially. There is an increasingly pressing need for a quantitative and predictive method to evaluate how low back pain trajectories are classified and, subsequently, how we can more effectively intervene during these progression stages.

Methods

In order to better understand pain mechanisms, we investigated, using computational modeling, how best to describe pain trajectories by developing a platform by which we studied the transition of acute chronic pain.

Results

The present study uses a computational neuroscience-based method to conduct such trajectory research, motivated by the use of hypothalamic–pituitary–adrenal (HPA) axis activity-history over a time-period as a way to mimic pain trajectories. A numerical simulation study is presented as a “proof of concept” for this modeling approach.

Conclusions

This model and its simulation results have highlighted the feasibility and the potential of developing such a broader model for patient evaluations.

Impact of water therapy on pain management in patients with fibromyalgia: current perspectives

Exercise-related interventions have been recommended as one of the main components in the management of fibromyalgia syndrome (FMS). Water therapy, which combines water's physical properties and exercise benefits, has proven effective in improving the clinical symptoms of FMS, especially pain, considered the hallmark of this syndrome. However, to our knowledge, the mechanisms underlying water therapy effects on pain are still scarcely explored in the literature. Therefore, this narrative review aimed to present the current perspectives on water therapy and the physiological basis for the mechanisms supporting its use for pain management in patients with FMS. Furthermore, the effects of water therapy on the musculoskeletal, neuromuscular, cardiovascular, respiratory, and neuroendocrine systems and inflammation are also addressed. Taking into account the aspects reviewed herein, water therapy is recommended as a nonpharmacologic therapeutic approach in the management of FMS patients, improving pain, fatigue, and quality of life. Future studies should focus on clarifying whether mechanisms and long-lasting effects are superior to other types of nonpharmacological interventions, as well as the economic and societal impacts that this intervention may present.

Hypothalamic-pituitary-adrenal axis feedback sensitivity in different states of back pain

Pain normally signals a threat to bodily integrity and causes emotional distress. Acute pain serves a protective function, yet, when pain turns chronic, the protective function is lost. A chain of psychophysiological alterations including changes in the stress regulation system, apparent in dysfunctional activity and responsivity of the hypothalamic-pituitary-adrenal (HPA) axis, might be an important factor in this context. Moreover, maladaptive responses may be complicated by affective comorbid symptoms such as anxiety and depression, and alter nociceptive processing. However, the relationship among pain chronicity, stress regulation, and contributing components of comorbid symptomatology as well as somatosensory profiles has rarely been examined. In the present study, we obtained diurnal cortisol profiles at baseline and feedback regulation (following a dexamethasone suppression test (DST)) in subacute (SABP) and chronic (CBP) back pain patients and healthy control individuals (HC). We also assessed anxiety, depression and chronic stress levels and used quantitative sensory testing (QST) to detect sensory abnormalities. We found a hyper-suppression of cortisol following DST and thus enhanced negative stress feedback sensitivity in SABP compared to both CBP and HC. In SABP, DST-related cortisol levels were negatively associated with pain intensity, mediated by cold pain thresholds and anxiety. These data support a stress model of pain chronicity and suggest that stress responses might be indicators of individual vulnerability in the transition period of subacute pain.

Effects of stress on the corticolimbic system: implications for chronic pain

Stress has multifaceted effects on pain. On the one hand, it is a powerful inhibitor of nociception and inflammation; on the other hand, it contributes to enhanced pathological states including the establishment and continuation of chronic pain. These seemingly paradoxical effects can be better understood by investigating how stress-induced plasticity in particular brain circuitry contributes to the chronic pain state. This review presents the rationale and evidence for the interactions between stress and pain, emphasizing underlying mechanisms and putting forth the hypothesis that stress partly mediates the deleterious effects of pain on the corticolimbic system. First, a general description of the corticolimbic circuitry predisposing and amplifying chronic pain will be discussed, followed by an overview of the neurotoxic effects of stress hormones on this circuitry. Recent studies show that the resulting perturbations to these brain circuits have significant consequences both for chronic pain and for general regulation of the stress response, primarily through feedback mechanisms controlling the hypothalamic-pituitary-adrenal axis. This overlap in effected circuitry provides a key point of comparison between stress and pain, and the similarities between the plasticity induced by chronic pain and chronic stress will be examined here. Chronic pain patients have been shown to exhibit maladaptive stress responses in general and in response to pain; the cause of this response and its consequence on pain severity will then be reviewed. Finally, factors that have been shown to lead to resilience or vulnerability for chronic pain and maladaptive stress responses will be summarized.

Cortisol and Subjective Stress Responses to Acute Psychosocial Stress in Fibromyalgia Patients and Control Participants

OBJECTIVE

Hypothalamic-pituitary-adrenal axis dysfunction may play a role in fibromyalgia (FM) pathogenesis but it remains understudied in this disorder. Furthermore, early childhood adversities (ECA) are common in FM, but whether they moderate stress reactivity is unknown. Hence, we investigated cortisol and subjective responses to acute psychosocial stress in FM and controls, while adjusting for ECA.

METHODS

Twenty-seven female FM patients and 24 age-matched female controls were recruited in a tertiary care center and through advertisements, respectively. The Childhood Trauma Questionnaire was used to measure ECA history. Salivary cortisol levels and subjective stress ratings were measured at multiple time points before and after the Trier Social Stress Test (TSST) was administered.

RESULTS

Significant main effects of group [F(1,43) = 7.04, p = .011, lower in FM] and ECA [F(1,43) = 5.18, p = .028, higher in participants with ECA] were found for cortisol responses. When excluding controls with ECA (n = 5), a significant group-by-time interaction was found [F(6,39) = 2.60, p = .032], driven by a blunted response to the stressor in FM compared with controls (p = .037). For subjective stress responses, a significant main effect of group [F(1,45) = 10.69, p = .002, higher in FM] and a trend toward a group-by-time interaction effect [F(6,45) = 2.05, p = .078, higher in FM 30 minutes before and 30 and 75 minutes after the TSST, and impaired recovery (difference immediately after - 30 minutes after the TSST) in FM] were found.

CONCLUSIONS

Blunted cortisol responsivity to the TSST was observed in FM patients compared with controls without ECA. FM patients had higher subjective stress levels compared with controls, particularly at baseline and during recovery from the TSST. In FM patients, ECA history was not associated with cortisol or subjective stress levels or with responsivity to the TSST. Future research should investigate the mechanisms underlying hypothalamic-pituitary-adrenal axis dysregulation in FM.

Neonatal Handling Produces Sex Hormone-Dependent Resilience to Stress-Induced Muscle Hyperalgesia in Rats

Neonatal handling (NH) of male rat pups strongly attenuates stress response and stress-induced persistent muscle hyperalgesia in adults. Because female sex is a well established risk factor for stress-induced chronic muscle pain, we explored whether NH provides resilience to stress-induced hyperalgesia in adult female rats. Rat pups underwent NH, or standard (control) care. Muscle mechanical nociceptive threshold was assessed before and after water avoidance (WA) stress, when they were adults. In contrast to male rats, NH produced only a modest protection against WA stress-induced muscle hyperalgesia in female rats. Gonadectomy completely abolished NH-induced resilience in male rats but produced only a small increase in this protective effect in female rats. The administration of the antiestrogen drug fulvestrant, in addition to gonadectomy, did not enhance the protective effect of NH in female rats. Finally, knockdown of the androgen receptor by intrathecal antisense treatment attenuated the protective effect of NH in intact male rats. Together, these data indicate that androgens play a key role in NH-induced resilience to WA stress-induced muscle hyperalgesia.

PERSPECTIVE

NH induces androgen-dependent resilience to stress-induced muscle pain. Therefore, androgens may contribute to sex differences observed in chronic musculoskeletal pain and its enhancement by stress.

Understanding taurine CNS activity using alternative zebrafish models

Taurine is a highly abundant "amino acid" in the brain. Despite the potential neuroactive role of taurine in vertebrates has long been recognized, the underlying molecular mechanisms related to its pleiotropic effects in the brain remain poorly understood. Due to the genetic tractability, rich behavioral repertoire, neurochemical conservation, and small size, the zebrafish (Danio rerio) has emerged as a powerful candidate for neuropsychopharmacology investigation and in vivo drug screening. Here, we summarize the main physiological roles of taurine in mammals, including neuromodulation, osmoregulation, membrane stabilization, and antioxidant action. In this context, we also highlight how zebrafish models of brain disorders may present interesting approaches to assess molecular mechanisms underlying positive effects of taurine in the brain. Finally, we outline recent advances in zebrafish drug screening that significantly improve neuropsychiatric translational researches and small molecule screens.

The Role of Stress Regulation on Neural Plasticity in Pain Chronification

Pain, especially chronic pain, is one of the most common clinical symptoms and has been considered as a worldwide healthcare problem. The transition from acute to chronic pain is accompanied by a chain of alterations in physiology, pathology, and psychology. Increasing clinical studies and complementary animal models have elucidated effects of stress regulation on the pain chronification via investigating activations of the hypothalamic-pituitary-adrenal (HPA) axis and changes in some crucial brain regions, including the amygdala, prefrontal cortex, and hippocampus. Although individuals suffer from acute pain benefit from such physiological alterations, chronic pain is commonly associated with maladaptive responses, like the HPA dysfunction and abnormal brain plasticity. However, the causal relationship among pain chronification, stress regulation, and brain alterations is rarely discussed. To call for more attention on this issue, we review recent findings obtained from clinical populations and animal models, propose an integrated stress model of pain chronification based on the existing models in perspectives of environmental influences and genetic predispositions, and discuss the significance of investigating the role of stress regulation on brain alteration in pain chronification for various clinical applications.

A users guide to HPA axis research

Glucocorticoid hormones (cortisol and corticosterone - CORT) are the effector hormones of the hypothalamic-pituitary-adrenal (HPA) axis neuroendocrine system. CORT is a systemic intercellular signal whose level predictably varies with time of day and dynamically increases with environmental and psychological stressors. This hormonal signal is utilized by virtually every cell and physiological system of the body to optimize performance according to circadian, environmental and physiological demands. Disturbances in normal HPA axis activity profiles are associated with a wide variety of physiological and mental health disorders. Despite numerous studies to date that have identified molecular, cellular and systems-level glucocorticoid actions, new glucocorticoid actions and clinical status associations continue to be revealed at a brisk pace in the scientific literature. However, the breadth of investigators working in this area poses distinct challenges in ensuring common practices across investigators, and a full appreciation for the complexity of a system that is often reduced to a single dependent measure. This Users Guide is intended to provide a fundamental overview of conceptual, technical and practical knowledge that will assist individuals who engage in and evaluate HPA axis research. We begin with examination of the anatomical and hormonal components of the HPA axis and their physiological range of operation. We then examine strategies and best practices for systematic manipulation and accurate measurement of HPA axis activity. We feature use of experimental methods that will assist with better understanding of CORT's physiological actions, especially as those actions impact subsequent brain function. This research approach is instrumental for determining the mechanisms by which alterations of HPA axis function may contribute to pathophysiology.

Fibromyalgia: A Critical and Comprehensive Review

Fibromyalgia is a disorder that is part of a spectrum of syndromes that lack precise classification. It is often considered as part of the global overview of functional somatic syndromes that are otherwise medically unexplained or part of a somatization disorder. Patients with fibromyalgia share symptoms with other functional somatic problems, including issues of myalgias, arthralgias, fatigue and sleep disturbances. Indeed, there is often diagnostic and classification overlap for the case definitions of a variety of somatization disorders. Fibromyalgia, however, is a critically important syndrome for physicians and scientists to be aware of. Patients should be taken very seriously and provided optimal care. Although inflammatory, infectious, and autoimmune disorders have all been ascribed to be etiological events in the development of fibromyalgia, there is very little data to support such a thesis. Many of these disorders are associated with depression and anxiety and may even be part of what has been sometimes called affected spectrum disorders. There is no evidence that physical trauma, i.e., automobile accidents, is associated with the development or exacerbation of fibromyalgia. Treatment should be placed on education, patient support, physical therapy, nutrition, and exercise, including the use of drugs that are approved for the treatment of fibromyalgia. Treatment should not include opiates and patients should not become poly pharmacies in which the treatment itself can lead to significant morbidities. Patients with fibromyalgia are living and not dying of this disorder and positive outlooks and family support are key elements in the management of patients.

Potential pleiotropic beneficial effects of adjuvant melatonergic treatment in posttraumatic stress disorder

Loss of circadian rhythmicity fundamentally affects the neuroendocrine, immune, and autonomic system, similar to chronic stress and may play a central role in the development of stress-related disorders. Recent articles have focused on the role of sleep and circadian disruption in the pathophysiology of posttraumatic stress disorder (PTSD), suggesting that chronodisruption plays a causal role in PTSD development. Direct and indirect human and animal PTSD research suggests circadian system-linked neuroendocrine, immune, metabolic and autonomic dysregulation, linking circadian misalignment to PTSD pathophysiology. Recent experimental findings also support a specific role of the fundamental synchronizing pineal hormone melatonin in mechanisms of sleep, cognition and memory, metabolism, pain, neuroimmunomodulation, stress endocrinology and physiology, circadian gene expression, oxidative stress and epigenetics, all processes affected in PTSD. In the current paper, we review available literature underpinning a potentially beneficiary role of an add-on melatonergic treatment in PTSD pathophysiology and PTSD-related symptoms. The literature is presented as a narrative review, providing an overview on the most important and clinically relevant publications. We conclude that adjuvant melatonergic treatment could provide a potentially promising treatment strategy in the management of PTSD and especially PTSD-related syndromes and comorbidities. Rigorous preclinical and clinical studies are needed to validate this hypothesis.

Increased percentages of regulatory T cells are associated with inflammatory and neuroendocrine responses to acute psychological stress and poorer health status in older men and women

RATIONALE

The percentage of regulatory T cells (TRegs)-a subtype of T lymphocyte that suppresses the immune response-appears to be reduced in a number of stress-related diseases. The role of the TReg in stress-disease pathways has not yet been investigated.

OBJECTIVES

The aim of the study was to investigate the association between biological responsivity to acute psychosocial stress and the percentage of TRegs in healthy older adults. The secondary purpose was to measure the associations between TReg percentage and psychological and physical well-being in the participants.

METHODS

Salivary cortisol and plasma interleukin (IL)-6 samples were obtained from 121 healthy older men and women from the Whitehall II cohort following acute psychophysiological stress testing. Three years later at a follow-up visit, we measured TReg percentages and psychological and physical well-being were recorded using the Short Form 36 Health Survey and the Center for Epidemiologic Studies Depression Scale.

RESULTS

Blunted cortisol responses (p = 0.004) and elevated IL-6 responses (p = 0.027) to acute psychophysiological stress were associated with greater TReg percentage independently of age, sex, BMI, smoking status, employment grade, time of testing, and baseline measures of cortisol and IL-6, respectively. Percentage of TRegs was associated cross-sectionally with lower physical (p = 0.043) and mental health status (p = 0.008), and higher levels of depressive symptoms (p = 0.002), independently of covariates.

CONCLUSIONS

Increased levels of TRegs may act as a defence against increased inflammation and may be a pre-indication for chronically stressed individuals on the cusp of clinical illness.

Suicide risk in patients with migraine and comorbid fibromyalgia

OBJECTIVES

To identify the frequency, clinical effects, and suicide risk in comorbid fibromyalgia(FM) among patients with migraine.

METHODS

We surveyed patients with migraine who attended a headache clinic. All patients completed questionnaires containing demographics, headache profiles based on the International Classification of Headache Disorders, 2nd edition, FM questionnaires based on the modified 2010 American College of Rheumatology preliminary diagnostic criteria, Migraine Disability Assessment, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index. Suicide risk was evaluated by self-report of lifetime suicidal ideation and attempts.

RESULTS

Of the 1,318 recruited patients with migraine (aged 42.6 ± 12.7 years; female/male = 4.5), 10.1% (aged 44.3 ± 12.6 years; female/male = 7.9) had comorbidity of FM. Patients with migraine and comorbid FM had higher headache frequency and headache-related disability, poor sleep quality, and were more depressed/anxious than those with migraine only (p < 0.001). Suicidal ideation and attempts were reported in 27.3% and 6.9% of patients with migraine, respectively, and were higher in patients with comorbid FM than in those without (ideation: 58.3% vs 24%; attempt: 17.6% vs 5.7%; p < 0.001). In addition, comorbidity of FM was associated with a higher suicide risk in 3 different migraine subgroups, i.e., migraine without aura, migraine with aura, and chronic migraine. After controlling for covariates, comorbidity of FM remained as a predictor of suicidal ideation and attempts (odds ratio 2.61 and 1.99, respectively, p < 0.05)in patients with migraine.

CONCLUSIONS

Comorbidity with FM is associated with a high suicide risk in patients with migraine.

A low cortisol response to stress is associated with musculoskeletal pain combined with increased pain sensitivity in young adults: a longitudinal cohort study

Background

In this study, we investigated whether an abnormal hypothalamic-pituitary-adrenal (HPA) axis response to psychosocial stress at 18 years of age is associated with musculoskeletal (MS) pain alone and MS pain combined with increased pain sensitivity at 22 years of age.

Methods

The study sample included 805 participants from the Western Australian Pregnancy Cohort (Raine) Study who participated in the Trier Social Stress Test (TSST) at age 18 years. Number of pain sites, pain duration, pain intensity and pain frequency were assessed at age 22 to measure severity of MS pain. Cold and pressure pain thresholds were determined at age 22. Group-based trajectory modeling was applied to establish cortisol response patterns based on the TSST. Logistic regression was used to study the association of TSST patterns with MS pain alone and MS pain combined with increased cold or pressure pain sensitivity, adjusted for relevant confounding factors. All analyses were stratified by sex.

Results

The mean (standard deviation) age during the TSST was 18.3 (0.3) years, and during MS pain assessment it was 22.2 (0.6). Forty-five percent of the participants were female. Three cortisol response patterns were identified, with cluster 1 (34 % of females, 21 % of males) reflecting hyporesponse, cluster 2 (47 %, 54 %) reflecting intermediate response and cluster 3 (18 %, 24 %) reflecting hyperresponse of the HPA axis. MS pain was reported by 42 % of females and 33 % of males at age 22 years. Compared with females in cluster 2, females in cluster 1 had an increased likelihood of having any MS pain (odds ratio 2.3, 95 % confidence interval 1.0–5.0) and more severe MS pain (2.8, 1.1–6.8) if their cold pain threshold was above the median. In addition, females in cluster 1 had an increased likelihood (3.5, 1.3–9.7) of having more severe MS pain if their pressure pain threshold was below the median. No statistically significant associations were observed in males.

Conclusions

This study suggests that a hyporesponsive HPA axis at age 18 years is associated with MS pain at 22 years in young females with increased pain sensitivity.

Temporal control of glucocorticoid neurodynamics and its relevance for brain homeostasis, neuropathology and glucocorticoid-based therapeutics

Glucocorticoids mediate plethora of actions throughout the human body. Within the brain, they modulate aspects of immune system and neuroinflammatory processes, interfere with cellular metabolism and viability, interact with systems of neurotransmission and regulate neural rhythms. The influence of glucocorticoids on memory and emotional behaviour is well known and there is increasing evidence for their involvement in many neuropsychiatric pathologies. These effects, which at times can be in opposing directions, depend not only on the concentration of glucocorticoids but also the duration of their presence, the temporal relationship between their fluctuations, the co-influence of other stimuli, and the overall state of brain activity. Moreover, they are region- and cell type-specific. The molecular basis of such diversity of effects lies on the orchestration of the spatiotemporal interplay between glucocorticoid- and mineralocorticoid receptors, and is achieved through complex dynamics, mainly mediated via the circadian and ultradian pattern of glucocorticoid secretion. More sophisticated methodologies are therefore required to better approach the study of these hormones and improve the effectiveness of glucocorticoid-based therapeutics.

Gut pain & visceral hypersensitivity

Visceral pain is a highly complex entity whose experience is variable in health and disease. It can occur in patients with organic disease and also in those without any readily identifiable structural or biochemical abnormality such as in the functional gastrointestinal disorders (FGID). Despite considerable progress in our understanding of the culpable underlying mechanisms significant knowledge gaps remain, representing a significant unmet need in gastroenterology. A key, but not universal, pathological feature is that patients with FGID often display heightened sensitivity to experimental gut stimulation, termed visceral hypersensitivity. A plethora of factors have been proposed to account for this epiphenomenon including peripheral sensitization, central sensitization, aberrant central processing, genetic, psychological and abnormalities within the stress responsive systems. Further research is needed, bringing together complementary research themes from a diverse array of academic disciplines ranging from gastroenterology to nociceptive physiology to functional neuro-imaging, to address this unmet need.

Assessing the prevalence of autoimmune, endocrine, gynecologic, and psychiatric comorbidities in an ethnically diverse cohort of female fibromyalgia patients: does the time from hysterectomy provide a clue?

Background

This retrospective chart review investigated differences in the prevalence of medical comorbidity between women with fibromyalgia (FM) (n=219) and a control group women with chronic pain (CP) without FM (n=116). The specific aims were to compare the prevalence of autoimmune, psychiatric, endocrine, gynecologic pathology, the relationship between timing of gynecologic surgery, and pain onset. We additionally sought to compare the number of comorbidities in an ethnically diverse cohort.

Methods

This was a retrospective chart review of patients seen in FM or CP clinics at an academic medical center in 2009–2010.

Results

Logistic regression modeling found that gynecologic, endocrine, and autoimmune diagnoses were independently associated with a diagnosis of FM. Detailed analyses showed that thyroid disease (P<0.01) and gynecologic surgery (P<0.05) were significantly more common in FM. Women with FM were more likely to have multiple autoimmune, endocrine, gynecologic, or psychiatric pathologies. A relationship was observed between the timing of gynecologic surgery and pain onset in FM, with more surgeries observed in the years just prior to pain onset or in the year after pain onset. A similar pattern was not found in the control group.

Conclusion

This study demonstrates that autoimmune, endocrine, and gynecologic pathologies occur more commonly in women with FM than in those with CP, which is consistent with findings in less ethnically diverse samples. Moreover, a relationship was found between timing of pain onset and gynecologic surgery. A larger prospective study of the relationship between gynecologic surgery and pain onset in FM is warranted.

Does aerobic exercise affect the hypothalamic-pituitary-adrenal hormonal response in patients with fibromyalgia syndrome?

[Purpose] The hypothalamic-pituitary-adrenal (HPA) axis in the etiopathogenesis of fibromyalgia is not clear. This study aimed to analyze the effects of a 6-week aerobic exercise program on the HPA axis in patients with fibromyalgia and to investigate the effects of this program on the disease symptoms, patients' fitness, disability, and quality of life. [Subjects and Methods] Fifty fibromyalgia patients were randomized to Group 1 (stretching and flexibility exercises at home for 6 weeks) and Group 2 (aerobic exercise three times a week and the same at-home exercises as Group 1 for 6 weeks). Serum levels of cortisol, adrenocorticotropic hormone, insulin-like growth factor-1, and growth hormone were analyzed at baseline and at the end of, and 1 hr after an exercise stress test. [Results] Group 2 showed better improvement in morning stiffness duration and pain. Growth hormone levels significantly increased after intervention and cortisol levels significantly decreased at time-time interaction in both groups. No significant differences in adrenocorticotropic hormone and insulin-like growth factor-1 were found. [Conclusion] The results of this study seem to support the hypothesis that there is a dysregulation of the HPA axis in patients with FM, and that a six-week exercise program can influence symptoms and affect the HPA axis hormones.

Interoception and stress

Afferent neural signals are continuously transmitted from visceral organs to the brain. Interoception refers to the processing of visceral-afferent neural signals by the central nervous system, which can finally result in the conscious perception of bodily processes. Interoception can, therefore, be described as a prominent example of information processing on the ascending branch of the brain–body axis. Stress responses involve a complex neuro-behavioral cascade, which is elicited when the organism is confronted with a potentially harmful stimulus. As this stress cascade comprises a range of neural and endocrine pathways, stress can be conceptualized as a communication process on the descending branch of the brain–body axis. Interoception and stress are, therefore, associated via the bi-directional transmission of information on the brain–body axis. It could be argued that excessive and/or enduring activation (e.g., by acute or chronic stress) of neural circuits, which are responsible for successful communication on the brain–body axis, induces malfunction and dysregulation of these information processes. As a consequence, interoceptive signal processing may be altered, resulting in physical symptoms contributing to the development and/or maintenance of body-related mental disorders, which are associated with stress. In the current paper, we summarize findings on psychobiological processes underlying acute and chronic stress and their interaction with interoception. While focusing on the role of the physiological stress axes (hypothalamic-pituitary-adrenocortical axis and autonomic nervous system), psychological factors in acute and chronic stress are also discussed. We propose a positive feedback model involving stress (in particular early life or chronic stress, as well as major adverse events), the dysregulation of physiological stress axes, altered perception of bodily sensations, and the generation of physical symptoms, which may in turn facilitate stress.

Hormone testing and treatment enters pain care

A number of factors have recently coalesced to bring hormone testing and treatment to the field of pain care. Uncontrolled, severe pain as well as opioid drugs have a profound impact on the endocrine system. Because pain is a potent stressor, it initially causes pituitary, adrenal, and gonadal hormones to elevate in the serum. If severe pain goes uncontrolled for too long, however, hormone levels deplete in the serum. The finding of abnormal (too high or low) serum hormone levels serve as biomarker of endocrinopathies, which helps inform the clinician that enhanced analgesia as well as hormone replacement may be necessary. Adequate, physiologic levels of some specific hormones are necessary for optimal analgesia, neuroprotection, and neurogenesis. Although not a substitute for opioids, some hormone replacements may minimize their use. We know that the central nervous system produces a group of hormones called neurohormones whose natural function is neuroprotection and neurogenesis. Their clinical use in centralized pain states is new, and early reports indicate that they may have considerable benefit for treatment.

No effects of hydrocortisone and dexamethasone on pain sensitivity in healthy individuals

BACKGROUND

There is some evidence that stress-induced cortisol increase leads to a decrease in pain, while lowering cortisol levels enhances pain sensitivity, but no study has yet investigated both pharmacological enhancement and reduction of cortisol levels in the same individuals.

METHODS

Firstly, we tested in 16 healthy individuals whether the treatment with hydrocortisone and dexamethasone, respectively, results in altered pain thresholds. Secondly, we aimed to test whether hormone effects are different across the pain range by using ratings for pain stimuli with varying intensity; and thirdly, we tested whether cortisol levels influence the discrimination ability for painful stimuli.

RESULTS

Despite substantial effects of dexamethasone and hydrocortisone administration on cortisol levels, no effect of these drugs was seen in terms of pain sensitivity (pain threshold, pain rating, pain discrimination ability), although comprehensively examined. However, in the placebo condition, a significant negative correlation between cortisol and pain thresholds was seen. Similarly, there were also strong negative associations between cortisol levels in the placebo condition and pain thresholds after drug treatment (especially after hydrocortisone).

CONCLUSION

These findings suggest that short-term variations of cortisol do not influence pain sensitivity whereas, in general, high levels of cortisol are associated with increased pain sensitivity, at least for weak to moderate stimuli.

Preliminary evidence of a blunted anti-inflammatory response to exhaustive exercise in fibromyalgia

Exercise intolerance, as evidenced by a worsening of pain, fatigue, and stiffness after novel exertion, is a key feature of fibromyalgia (FM). In this pilot study, we investigate whether; insufficient muscle repair processes and impaired anti-inflammatory mechanisms result in an exaggerated pro-inflammatory cytokine response to exhaustive exercise, and consequently a worsening of muscle pain, stiffness and fatigue in the days post-exercise. We measured changes in muscle pain and tenderness, fatigue, stiffness, and serum levels of neuroendocrine and inflammatory cytokine markers in 20 women with FM and 16 healthy controls (HCs) before and after exhaustive treadmill exercise. Compared to HCs, FM participants failed to mount the expected anti-inflammatory response to exercise and experienced a worsening of symptoms post-exercise. However, changes in post-exertional symptoms were not mediated by post-exertional changes in pro-inflammatory cytokine levels. Implications of these findings are discussed.

Activation in the hypothalamic-pituitary-adrenocortical axis and sympathetic nervous system in women with carpal tunnel syndrome

OBJECTIVE

The aim of this study is to investigate the differences in salivary cortisol (hypothalamic-pituitary-adrenocortical [HPA] axis), α-amylase activity (sympathetic nervous system [SNS]), and immunoglobulin A (IgA; immune system) concentrations between women with carpal tunnel syndrome (CTS) and healthy women.

DESIGN

A cross-sectional study.

SETTING

Activation of HPA, SNS, and immune system in CTS has not been clearly determined.

PATIENTS

One hundred two women (age: 45 ± 7 years) with electrodiagnostic and clinical diagnosis of CTS and 102 matched healthy women.

OUTCOME MEASURES

The intensity of the pain was assessed with a Numerical Pain Rating Scale (0-10), and disability was determined with Boston Carpal Tunnel Questionnaire. Salivary cortisol concentration, α-amylase activity, salivary flow rate, and IgA concentration were collected from nonstimulated saliva.

RESULTS

Women with CTS exhibited lower salivary flow rate (P < 0.001) and higher α-amylase activity (P < 0.01) than controls. No significant differences for cortisol and IgA concentrations (P > 0.2) were found between groups as a total. Women with severe CTS exhibited lower salivary flow rate (P < 0.001), higher α-amylase activity (P = 0.002), and higher cortisol concentration (P = 0.03) than healthy women and than those with minimal/moderate CTS (P < 0.05). Within women with CTS, significant positive associations between α-amylase activity and the intensity of pain were found: the highest the level of pain, the higher the α-amylase activity, i.e., higher SNS activation.

CONCLUSIONS

These results suggest that women with severe CTS exhibit changes in activation in the HPA axis and SNS but not in the humoral immune system. Activation of the SNS was associated with the intensity of pain. Future studies are needed to elucidate the direction of this relationship.

Mechanisms of visceral pain in health and functional gastrointestinal disorders

Background and aims Chronic visceral pain is common both in patients with identifiable organic disease and also in those without any structural, biochemical or immunological abnormality such as in the functional gastrointestinal disorders (FGIDs). We aim to provide a contemporaneous summary of pathways involved in visceral nociception and how a variety of mechanisms may influence an individual's experience of visceral pain. Methods In this narrative review, we have brought together evidence through a detailed search of Medline in addition to using our experience and exposure to recent research developments from ourselves and other research groups. Results FGIDs are a heterogeneous group of disorders whose aetiology largely remains an enigma. The germane hypothesis for the genesis and maintenance of chronic visceral pain in FGIDs is the concept of visceral hypersensitivity. A number of peripheral and central mechanisms have been proposed to account for this epiphenomenon. In the periphery, inflammatory mediators activate and sensitize nociceptive afferent nerves by reducing their transduction thresholds and by inducing the expression and recruitment of hitherto silent nociceptors culminating in an increase in pain sensitivity at the site of injury known as primary hyperalgesia. Centrally, secondary hyperalgesia, defined as an increase in pain sensitivity in anatomically distinct sites, occurs at the level of the spinal dorsal horn. Moreover, the stress responsive physiological systems, genetic and psychological factors may modulate the experience of visceral pain. We also address some novel aetiological concepts in FGIDs, namely the gastrointestinal microbiota, connective tissue abnormalities and the gastrointestinal neuromuscular disorders. Firstly, the gastrointestinal microbiota is a diverse and dynamic ecosystem, that safeguards the host from external pathogens, aids in the metabolism of polysaccharides and lipids, modulates intestinal motility, in addition to modulating visceral perception. Secondly, connective tissue disorders, which traditionally have been considered to be confined largely to the musculoskeletal system, have an increasing evidence base demonstrating the presence of visceral manifestations. Since the sensorimotor apparatus of the GI tract is embedded within connective tissue it should not be surprising that such disorder may result in visceral pain and abnormal gut motility. Thirdly, gastrointestinal neuromuscular diseases refer to a heterogeneous group of disorders in which symptoms arise from impaired GI motor activity often manifesting as abnormal transit with or without radiological evidence of transient or persistent dilation of the viscera. Although a number of these are readily recognizable, such as achalasia or Hirschsprung's disease, the cause in a number of patients is not. An international working group has recently addressed this "gap", providing a comprehensive morphologically based diagnostic criteria. Conclusions/implications Although marked advances have been made in understanding the mechanisms that contribute to the development and maintenance of visceral pain, many interventions have failed to produce tangible improvement in patient outcomes. In the last part of this review we highlight an emerging approach that has allowed the definition and delineation of temporally stable visceral pain clusters, which may improve participant homogeneity in future studies, potentially facilitate stratification of treatment in FGID and lead to improvements in diagnostic criteria and outcomes.

Cortisol response to experimental pain in patients with chronic low back pain and patients with major depression

OBJECTIVE

Chronic pain and major depression have been associated with alterations of the hypothalamus-pituitary-adrenal axis (HPA) activity. Previous studies suggested that HPA activity is diminished in chronic pain but increased in depression. However, little is known about the effects of experimentally induced acute pain on cortisol secretion in patients with chronic pain and depression.

METHODS

On three different occasions (day 1, day 8, day 90), we repeatedly examined 20 patients with chronic low back pain without depression, 22 patients with major depression without pain, and 33 healthy subjects using heat stimuli. Pain intensity was rated by participants using a visual analog scale. Salivary cortisol was assessed prior to 10 blocks of repeated painful heat stimuli, and 45 and 60 minutes afterwards.

RESULTS

In repeated measures analyses of covariance adjusting for age, sex, and time of examination, we found a significant effect of group (P < 0.01) and post-hoc tests confirmed that patients with chronic pain had lower cortisol area-under-the-curve values compared with healthy controls and depressed patients at all time points (all P values <0.01). However, cortisol secretion in depressed patients did not differ from controls.

CONCLUSIONS

Across groups, experimental heat pain stimuli did not elicit a significant cortisol response. Chronic pain appears to be associated with low cortisol secretion. The mechanisms linking chronic pain with low cortisol deserve further study.

Circadian rhythm of serum cortisol in female patients with fibromyalgia syndrome

Fibromyalgia syndrome (FMS) patients have disturbed sleep patterns which may lead to altered circadian rhythm in serum cortisol secretion. The aim of this study was to assess circadian changes, if any, in serum cortisol levels in female patients with FMS. Cortisol levels were estimated every 6 h during 24 h period; in 40 female patients satisfying ACR criteria for FMS (Age 36.4 ± 9.9), and 40 healthy females without FMS (Age 33.8 ± 11.1). A significant difference in the night time serum cortisol level was observed among the patients and control groups (patients, 12.9 ± 9.7 controls 5.8 ± 3.0; p < 0.01). However, no significant difference was found in serum cortisol levels in patients and control groups in the morning (patients, 28.4 ± 13.2 controls, 27.6 ± 14.5; p > 0.05), afternoon (patients, 14.4 ± 5.6 controls, 14.0 ± 6.6; p > 0.05) and evening hours (patients, 10.9 ± 5.8 controls, 8.9 ± 3.6; p > 0.05). It could be concluded that there is an abnormality in circadian secretion of cortisol in female FMS patients.

Evidence for an association between an enhanced reactivity of interleukin-6 levels and reduced glucocorticoid sensitivity in patients with fibromyalgia

Pain and fatigue have been identified as core symptoms of fibromyalgia syndrome (FMS). Since both symptoms are also characteristic of hypocortisolemic disorders, reduced cortisol levels have been thought to promote an exacerbation of these FMS core symptoms by an enhanced reactivity of interleukin-6 (IL-6) levels. The aim of the current study was to investigate the pathophysiologic relevance of reduced cortisol levels for manifestation of FMS core symptoms. Twelve female FMS patients with 15 female controls were compared regarding the function of hypothalamus-pituitary-adrenal (HPA) axis and behavioral, endocrine and IL-6 responses after measuring the pressure pain thresholds (PPTs) at tender points. Function of HPA axis was assessed by determining the cortisol awakening response, daytime profile of cortisol secretion, low dose overnight dexamethasone suppression test (DST) and glucocorticoid sensitivity (GC) of inflammatory cytokine production. While endocrine and IL-6 responses were determined by collecting blood and saliva samples behavioral responses were assessed by pain and fatigue recordings of participants before and after PPT measurement using visual analogue scale (VAS). Whereas FMS patients were found not to differ from controls in cortisol awakening response, daytime profile of cortisol secretion and cortisol suppression after overnight DST, they did exhibit a reduced GC sensitivity of inflammatory cytokine production. PPT measurement did induce three times higher cortisol and four times higher IL-6 levels in FMS patients, but no change in their ACTH levels. The enhanced IL-6 reactivity after PPT measurement was accompanied by an increase in the severity of FMS patients' pain and fatigue ratings. The findings of the present study provide evidence for the pathophysiologic relevance of a disturbed glucocorticoid receptor (GR) function, rather than reduced cortisol levels for the maintenance of FMS core symptoms.

Differential sensitivity to life stress in FMR1 premutation carrier mothers of children with fragile X syndrome

OBJECTIVE

The premutation of the FMR1 gene (defined as between 55 and 200 CGG repeats) is estimated to affect 1 in 149 females and 1 in 643 males, and some people who carry the FMR1 premutation display signs of impairment.

METHOD

This study focuses on 82 premutation carrier mothers (M age = 51.4 years; SD = 7.7) of adolescent and adult children with fragile X syndrome (FXS). A Gene × Environment interaction approach examined the ways in which the experience of negative life events interacts with genetic vulnerability to predict depressive symptoms, anxiety, and daily cortisol levels.

RESULTS

The associations of life events with all 3 dependent measures were associated with CGG repeat length but in a curvilinear manner. Mothers with midsize CGG repeats who experienced above-average numbers of negative life events in the previous year had more depressive symptoms and anxiety and had a blunted cortisol awakening response, as compared with those with higher or lower repeat lengths. However, mothers with midsize CGG repeats who experienced below-average numbers of negative life events in the previous year had the lowest levels of depressive symptoms and anxiety, and they exhibited the typical cortisol response to awakening, meeting the criteria for differential susceptibility.

CONCLUSIONS

This research extends our understanding of the phenotypic effects of the expansion of the FMR1 gene, and it adds to the growing literature on the curvilinear relationship between CGG repeat length and mental and physical health.

Fibromyalgia and depression

Fibromyalgia and depression might represent two manifestations of affective spectrum disorder. They share similar pathophysiology and are largely targeted by the same drugs with dual action on serotoninergic and noradrenergic systems. Here, we review evidence for genetic and environmental factors that predispose, precipitate, and perpetuate fibromyalgia and depression and include laboratory findings on the role of depression in fibromyalgia. Further, we comment on several aspects of fibromyalgia which support the development of reactive depression, substantially more so than in other chronic pain syndromes. However, while sharing many features with depression, fibromyalgia is associated with somatic comorbidities and absolutely defined by fluctuating spontaneous widespread pain. Fibromyalgia may, therefore, be more appropriately grouped together with other functional pain disorders, while psychologically distressed subgroups grouped additionally or solely with affective spectrum disorders.

Salivary cortisol and melatonin levels in children with frequent episodic tension-type headache do not differ from healthy children

AIM

To investigate the differences in cortisol and melatonin concentrations between children with frequent episodic tension-type headache (FETTH) and healthy children.

METHODS

Forty-four children, 12 boys/32 girls (age: 9 ± 2 years) with FETTH associated to peri-cranial tenderness and 44 age- and sex- matched healthy children participated. Both salivary cortisol and melatonin concentrations were collected from non-stimulated saliva following standardized guidelines. A headache diary for 4 weeks was used for collecting intensity, frequency and duration of headache.

RESULTS

No significant differences for cortisol (t = -0.431; p = 0.668), and melatonin (z = -1.564; p = 0.118) concentrations and salivary flow rate (z = -1.190; p = 0.234) were found between both groups. No significant effect of age or gender was found. In addition, no significant association between cortisol-melatonin concentrations and between cortisol-melatonin concentrations and headache clinical parameters were found.

CONCLUSION

These results suggest that children with FETTH, at first instance, do not present deficits in the secretion of these cortisol and melatonin. Prospective longitudinal studies are needed to further elucidate the direction of current findings, particularly the synchronism of cortisol and melatonin and the course of the headache.

Effects of psychosocial stress on the pattern of salivary protein release

Previous research suggests that acute stress can increase the release of immune-relevant proteins in saliva. However, no attempts have been made to examine a wider range of salivary proteins in response to stress. In this study, we identified and quantified changes in the pattern of salivary protein release in a 45 min time period following the Trier Social Stress Test (TSST) in 12 asthmatic and 13 healthy participants. Proteins were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. The relative protein amounts were quantified using the Image J software (NIH), and identified and characterized using mass spectroscopy. Negative affect was increased immediately after stress in both groups. The results showed that alpha amylase, cystatin S and light chain IgA were increased after the TSST and significant increases in glutathione S-transferase and prolactin inducible protein were also observed. Asthma patients showed responses similar to healthy controls, but had a tendency toward overall lower alpha amylase levels. Our findings suggest that a variety of proteins relevant to mucosal immunity are elevated following acute psychosocial stress, including glutathione S-transferase and prolactin inducible protein, which had not been characterized in this context before.

An eight-week yoga intervention is associated with improvements in pain, psychological functioning and mindfulness, and changes in cortisol levels in women with fibromyalgia

Objectives:

Fibromyalgia (FM) is a chronic condition characterized by widespread musculoskeletal pain, fatigue, depression, and hypocortisolism. To date, published studies have not investigated the effects of yoga on cortisol in FM. This pilot study used a time series design to evaluate pain, psychological variables, mindfulness, and cortisol in women with FM before and after a yoga intervention.

Methods:

Participants (n = 22) were recruited from the community to participate in a 75 minute yoga class twice weekly for 8 weeks. Questionnaires concerning pain (intensity, unpleasantness, quality, sum of local areas of pain, catastrophizing, acceptance, disability), anxiety, depression, and mindfulness were administered pre-, mid- and post-intervention. Salivary cortisol samples were collected three times a day for each of two days, pre- and post-intervention.

Results:

Repeated measures analysis of variance (ANOVA) revealed that mean ± standard deviation (SD) scores improved significantly (p < 0.05) from pre- to post-intervention for continuous pain (pre: 5.18 ± 1.72; post: 4.44 ± 2.03), pain catastrophizing (pre: 25.33 ± 14.77; post: 20.40 ± 17.01), pain acceptance (pre: 60.47 ± 23.43; post: 65.50 ± 22.93), and mindfulness (pre: 120.21 ± 21.80; post: 130.63 ± 20.82). Intention-to-treat analysis showed that median AUC for post-intervention cortisol (263.69) was significantly higher (p < 0.05) than median AUC for pre-intervention levels (189.46). Mediation analysis revealed that mid-intervention mindfulness scores significantly (p < 0.05) mediated the relationship between pre- and post-intervention pain catastrophizing scores.

Discussion:

The results suggest that a yoga intervention may reduce pain and catastrophizing, increase acceptance and mindfulness, and alter total cortisol levels in women with FM. The changes in mindfulness and cortisol levels may provide preliminary evidence for mechanisms of a yoga program for women with FM. Future studies should use an RCT design with a larger sample size.

Helplessness and perceived pain intensity: relations to cortisol concentrations after electrocutaneous stimulation in healthy young men

Background

Uncontrollable aversive events are associated with feelings of helplessness and cortisol elevation and are suitable as a model of depression. The high comorbidity of depression and pain symptoms and the importance of controllability in both conditions are clinically well-known but empirical studies are scarce. The study investigated the relationship of pain experience, helplessness, and cortisol secretion after controllable vs. uncontrollable electric skin stimulation in healthy male individuals.

Methods

Sixty-four male volunteers were randomly assigned to receive 30 controllable (self-administered) or uncontrollable (experimenter-administered) painful electric skin stimuli. Perceived pain intensity (PPI), subjective helplessness ratings, and salivary cortisol concentrations were assessed. PPI was assessed after stress exposure. For salivary cortisol concentrations and subjective helplessness ratings, areas under the response curve (AUC) were calculated.

Results

After uncontrollable vs. controllable stress exposure significantly higher PPI ratings (P = 0.023), higher subjective helplessness AUC (P < 0.0005) and higher salivary cortisol AUC (P = 0.004, t-tests) were found. Correlation analyses revealed a significant correlation between subjective helplessness AUC and PPI (r = 0.500, P < 0.0005), subjective helplessness AUC and salivary cortisol AUC (r = 0.304, P = 0.015) and between PPI and salivary cortisol AUC (r = 0.298, P = 0.017).

Conclusions

The results confirm the impact of uncontrollability on stress responses in humans; the relationship of PPI with subjective helplessness and salivary cortisol suggests a cognitive-affective sensitization of pain perception, particularly under uncontrollable conditions.