LONG-TERM ALTERATION OF DAILY MELATONIN, 6-SULFATOXYMELATONIN, CORTISOL, AND TEMPERATURE PROFILES IN BURN PATIENTS: A PRELIMINARY REPORT

IL-10-induced STAT3/NF-κB crosstalk modulates pineal and extra-pineal melatonin synthesis

Immune-pineal axis activation is part of the assembly of immune responses. Proinflammatory cytokines inhibit the pineal synthesis of melatonin while inducing it in macrophages by mechanisms dependent on nuclear factor-κB (NF-κB) activation. Cytokines activating the Janus kinase/signal transducer and activator of transcription (STAT) pathways, such as interferon-gamma (IFN-γ) and interleukin-10 (IL-10), modulate melatonin synthesis in the pineal, bone marrow (BM), and spleen. The stimulatory effect of IFN-γ upon the pineal gland depends on STAT1/NF-κB interaction, but the mechanisms controlling IL-10 effects on melatonin synthesis remain unclear. Here, we evaluated the role of STAT3 and NF-κB activation by IL-10 upon the melatonin synthesis of rats' pineal gland, BM, spleen, and peritoneal cells. The results show that IL-10-induced interaction of (p)STAT3 with specific NF-κB dimmers leads to different cell effects. IL-10 increases the pineal's acetylserotonin O-methyltransferase (ASMT), N-acetylserotonin, and melatonin content via nuclear translocation of NF-κB/STAT3. In BM, the nuclear translocation of STAT3/p65-NF-κB complexes increases ASMT expression and melatonin content. Increased pSTAT3/p65-NF-κB nuclear translocation in the spleen enhances phosphorylated serotonin N-acetyltransferase ((p)SNAT) expression and melatonin content. Conversely, in peritoneal cells, IL-10 leads to NF-κB p50/p50 inhibitory dimmer nuclear translocation, decreasing (p)SNAT expression and melatonin content. In conclusion, IL-10's effects on melatonin production depend on the NF-κB subunits interacting with (p)STAT3. Thus, variations of IL-10 levels and downstream pathways during immune responses might be critical regulatory factors adjusting pineal and extra-pineal synthesis of melatonin.

Determining rhythmicity and determinism of temperature curves in septic and non-septic critically ill patients through chronobiological and recurrence quantification analysis: a pilot study

BACKGROUND

A few studies have demonstrated that critically ill patients exhibit circadian deregulation and reduced complexity of different time series, such as temperature.

RESULTS

In this prospective study, we enrolled 21 patients divided into three groups: group A (N = 10) included subjects who had septic shock at the time of ICU entry, group B (N = 6) included patients who developed septic shock during ICU stay, and group C consisted of 5 non-septic critically ill patients. Core body temperature (CBT) was recorded for 24 h at a rate of one sample per hour (average of CBT for that hour) and during different occasions: upon ICU entry and exit in groups A and C and upon entry, septic shock development, and exit in group B. Markers of circadian rhythmicity included mean values, amplitude that is the difference between peak and mean values, and peak time. Furthermore, recurrence quantification analysis (RQA) was employed for assessing different markers of complexity of temperature signals. Patients from group C exhibited higher temperature amplitude upon entry (0.45 ± 0.19) in relation with both groups A (0.28 ± 0.18, p < 0.05) and B (0.32 ± 0.13, p < 0.05). Circadian features did not differ within all groups. Temperature amplitude in groups B and C upon entry was negatively correlated with SAPS II (r = - 0.72 and - 0.84, p < 0.003) and APACHE II scores (r = - 0.70 and - 0.63, p < 0.003), respectively, as well as duration of ICU and hospital stay in group B (r = - 0.62 and - 0.64, p < 0.003) and entry SOFA score in group C (r = - 0.82, p < 0.003). Increased periodicity of CBT was found for all patients upon exit related to entry in the ICU. Different RQA features indicating periodic patterns of change of entry CBT were negatively correlated with severity of disease and length of ICU stay for all patients.

CONCLUSIONS

Increased temperature rhythmicity during ICU entry was related with lower severity of disease and better clinical outcomes, whereas the more deterministic CBT patterns were found in less critically ill patients with shorter ICU stay.

Relationship between circadian activity rhythms and fatigue in hospitalized children with CNS cancers receiving high-dose chemotherapy

PURPOSE

Robust circadian rhythms are increasingly recognized as essential to good health. Adult cancer patients with dysregulated circadian activity rhythms (CAR) experience greater fatigue, lower responsiveness to chemotherapy, and shorter time to relapse. There is scant research describing circadian rhythms and associated outcomes in children with cancer. As part of a larger study examining whether a cognitive-behavioral intervention could preserve sleep in children and adolescents with central nervous system cancers hospitalized for high-dose chemotherapy (HDCT), this study aimed to compare CAR of these children to published values and to investigate the relationship between CAR and fatigue.

METHODS

Participants aged 4-19 years wore an actigraph throughout their hospitalization (5 days). From activity counts recorded by actigraphy, six CAR variables were calculated: amplitude, 24-h autocorrelation (r24), dichotomy index (I < O), interdaily stability (IS), intradaily variability (IV), and acrophase. Parent-reported child fatigue and child/adolescent self-reported fatigue measures were collected daily.

RESULTS

Thirty-three participants were included. Three CAR variables (amplitude, r24, and I < O) showed dysregulation compared to published values. Older age was significantly associated with later acrophase and greater dysregulation of all other CAR variables. Controlling for age, more dysregulated amplitude (p = 0.001), r24 (p = 0.003), IS (p = 0.017), and IV (p = 0.001) were associated with higher parent-reported fatigue; more dysregulated IV (p = 0.003) was associated with higher child-reported fatigue.

CONCLUSIONS

Participants demonstrated dysregulated CAR during hospitalization for HDCT. Greater dysregulation was associated with greater fatigue. Research on circadian dysregulation and its relationship to health-related outcomes in children with cancer, and interventions to support circadian rhythmicity, is urgently needed.

Developmental Trajectories of Early Life Stress and Trauma: A Narrative Review on Neurobiological Aspects Beyond Stress System Dysregulation

Early life stressors display a high universal prevalence and constitute a major public health problem. Prolonged psychoneurobiological alterations as sequelae of early life stress (ELS) could represent a developmental risk factor and mediate risk for disease, leading to higher physical and mental morbidity rates in later life. ELS could exert a programming effect on sensitive neuronal brain networks related to the stress response during critical periods of development and thus lead to enduring hyper- or hypo-activation of the stress system and altered glucocorticoid signaling. In addition, alterations in emotional and autonomic reactivity, circadian rhythm disruption, functional and structural changes in the brain, as well as immune and metabolic dysregulation have been lately identified as important risk factors for a chronically impaired homeostatic balance after ELS. Furthermore, human genetic background and epigenetic modifications through stress-related gene expression could interact with these alterations and explain inter-individual variation in vulnerability or resilience to stress. This narrative review presents relevant evidence from mainly human research on the ten most acknowledged neurobiological allostatic pathways exerting enduring adverse effects of ELS even decades later (hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system and inflammation, oxidative stress, cardiovascular system, gut microbiome, sleep and circadian system, genetics, epigenetics, structural, and functional brain correlates). Although most findings back a causal relation between ELS and psychobiological maladjustment in later life, the precise developmental trajectories and their temporal coincidence has not been elucidated as yet. Future studies should prospectively investigate putative mediators and their temporal sequence, while considering the potentially delayed time-frame for their phenotypical expression. Better screening strategies for ELS are needed for a better individual prevention and treatment.

Multilevel Interactions of Stress and Circadian System: Implications for Traumatic Stress

The dramatic fluctuations in energy demands by the rhythmic succession of night and day on our planet has prompted a geophysical evolutionary need for biological temporal organization across phylogeny. The intrinsic circadian timing system (CS) represents a highly conserved and sophisticated internal "clock," adjusted to the 24-h rotation period of the earth, enabling a nyctohemeral coordination of numerous physiologic processes, from gene expression to behavior. The human CS is tightly and bidirectionally interconnected to the stress system (SS). Both systems are fundamental for survival and regulate each other's activity in order to prepare the organism for the anticipated cyclic challenges. Thereby, the understanding of the temporal relationship between stressors and stress responses is critical for the comprehension of the molecular basis of physiology and pathogenesis of disease. A critical loss of the harmonious timed order at different organizational levels may affect the fundamental properties of neuroendocrine, immune, and autonomic systems, leading to a breakdown of biobehavioral adaptative mechanisms with increased stress sensitivity and vulnerability. In this review, following an overview of the functional components of the SS and CS, we present their multilevel interactions and discuss how traumatic stress can alter the interplay between the two systems. Circadian dysregulation after traumatic stress exposure may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of trauma through maladaptive stress regulation. Understanding the mechanisms susceptible to circadian dysregulation and their role in stress-related disorders could provide new insights into disease mechanisms, advancing psychochronobiological treatment possibilities and preventive strategies in stress-exposed populations.

Melatonin and cortisol exhibit different circadian rhythm profiles during septic shock depending on timing of onset: a prospective observational study

Background

Septic shock has been found to disrupt circadian rhythms. Moreover, timing of onset has been associated with different circadian profiles in experimental studies.

Results

In this prospective study, we enrolled 26 patients divided into two groups: Group A (N = 15) included subjects who had septic shock at the time of ICU admission and Group B (N = 11) included patients who developed septic shock during ICU admission. 6-Sulfatoxymelatonin (aMT6s) and cortisol levels were measured in urine samples every 4 h over a 24-h period. Two sets of samples were taken from Group A (entry/septic shock and exit) and three sets from Group B (entry, septic shock and exit). Mean, amplitude that is the difference between peak and mean values, as well as peak time, were estimated for both aMT6s and cortisol. In Group A, amplitude of aMT6s upon entry (septic shock) was reduced in relation to exit (437.2 ± 309.2 vs. 674.1 ± 657.6 ng/4 h, p < 0.05). Peak time occurred earlier (10:00 p.m. vs. 07:00 a.m, p < 0.05) and correlated with higher APACHE II score and longer ICU stay. In Group B, aMT6s mean values were significantly increased during septic shock (2492.2 ± 1709.1 ng/4 h) compared to both entry (895.4 ± 715.5 ng/4 h) and exit (1308.6 ± 1214.4 ng/4 h, p < 0.05 for all comparisons). Amplitude of aMT6s was also elevated during septic shock (794.8 ± 431.8 ng/4 h) in relation to entry (293.1 ± 275.9 ng/4 h, p < 0.05). Regarding cortisol rhythm in Group A, during septic shock amplitude was increased compared to exit (13.3 ± 31 ng/4 h vs. 8.7 ± 21.2 ng/4 h p < 0.05) and correlated with reduced hospital length of stay. In Group B, cortisol mean values and amplitude during septic shock (10 ± 5.3 and 3 ± 1.8 ng/4 h, respectively) were significantly reduced compared to both entry (30 ± 57.9 and 12.3 ± 27.3 ng/4 h) and exit (14.4 ± 20.7 and 6.6 ± 8.7 ng/4 h, p < 0.05 for all comparisons) and correlated with higher SOFA score and longer ICU and hospital stay.

Conclusions

Septic shock induced inverse changes of aMT6s and cortisol circadian rhythm profiles both within and between different groups of patients, depending on timing of onset. Reduced rhythmicity was correlated with severity of disease and longer ICU stay.

Early life stress and trauma: developmental neuroendocrine aspects of prolonged stress system dysregulation

Experience of early life stress (ELS) and trauma is highly prevalent in the general population and has a high public health impact, as it can trigger a health-related risk cascade and lead to impaired homeostatic balance and elevated cacostatic load even decades later. The prolonged neuropsychobiological impact of ELS can, thus, be conceptualized as a common developmental risk factor for disease associated with increased physical and mental morbidity in later life. ELS during critical periods of brain development with elevated neuroplasticity could exert a programming effect on particular neuronal networks related to the stress response and lead to enduring neuroendocrine alterations, i.e., hyper- or hypoactivation of the stress system, associated with adult hypothalamic-pituitary-adrenal axis and glucocorticoid signaling dysregulation. This paper reviews the pathophysiology of the human stress response and provides evidence from human research on the most acknowledged stress axis-related neuroendocrine pathways exerting the enduring adverse effects of ELS and mediating the cumulative long-term risk of disease vulnerability in adulthood.

Circadian Rhythm Disruption in the Critically Ill: An Opportunity for Improving Outcomes

OBJECTIVES

Circadian rhythms are severely disrupted among the critically ill. These circadian arrhythmias impair mentation, immunity, autonomic function, endocrine activity, hormonal signaling, and ultimately healing. In this review, we present a modern model of circadian disruption among the critically ill, discuss causes of these circadian arrhythmias, review observational and intervention studies of the effects of circadian-rhythm-restoring factors on medical outcomes, and identify needed key trials of circadian interventions in the critically ill.

DATA SOURCES

MEDLINE, EMBASE, PsychINFO, Google Scholar through December 2014.

STUDY SELECTION

Articles relevant to circadian rhythms, melatonin, and light in the critically ill were selected.

DATA EXTRACTION AND DATA SYNTHESIS

Articles were synthesized for this review of circadian arrhythmia and the use of circadian-rhythm-restoring interventions among the critically ill.

CONCLUSIONS

Circadian disruption often demonstrates serial degradation: initially, the amplitude attenuates along with delayed circadian phase. With increasing acuity of illness, circadian rhythmicity may be lost entirely. Causes of chronodisruption may be environmental or internal to the patient. In particular, inadequate daytime illumination and nocturnal light pollution disrupt healthy circadian periodicity. Internal causes of circadian arrhythmia include critical illness itself and subjective experience of distress and pain. Observational studies of windowed rooms and real-time ambient lighting have found that physiologic light-dark patterns may support recovery from critical illness. Studies of early morning bright light or evening melatonin agonists have found improved rates of delirium, enhanced sleep, and lower arrhythmia prevalence. The current evidence base emphasizes that lighting and melatoninergic interventions deserve to be tested in full-scale trials.

When time stands still: an integrative review on the role of chronodisruption in posttraumatic stress disorder

PURPOSE OF REVIEW

The human circadian system creates and maintains cellular and systemic rhythmicity essential to homeostasis. Loss of circadian rhythmicity fundamentally affects the neuroendocrine, immune and autonomic system, similar to chronic stress and, thus, may play a central role in the development of stress-related disorders. This article focuses on the role of circadian misalignment in the pathophysiology of posttraumatic stress disorder (PTSD).

RECENT FINDINGS

Sleep disruption is a core feature of PTSD supporting the important supraordinate pathophysiological role of circadian system in PTSD. Furthermore, direct and indirect human and animal PTSD research suggests circadian system linked neuroendocrine, immune, metabolic and autonomic dysregulation with blunted diurnal rhythms, specific sleep pattern pathologies and cognitive deficits, as well as endocannabinoid and neuropeptide Y system alterations and altered circadian gene expression, linking circadian misalignment to PTSD pathophysiology.

SUMMARY

PTSD development is associated with chronodisruption findings. Evaluation and treatment of sleep and circadian disruption should be the first steps in PTSD management. State-of-the-art methods of circadian rhythm assessment should be applied to bridge the gap between clinical significance and limited understanding of the relationship between traumatic stress, sleep and circadian system.

'Chronomics' in ICU: circadian aspects of immune response and therapeutic perspectives in the critically ill

Complex interrelations exist between the master central clock, located in the suprachiasmatic nuclei of the hypothalamus, and several peripheral clocks, such as those found in different immune cells of the body. Moreover, external factors that are called ‘timekeepers’, such as light/dark and sleep/wake cycles, interact with internal clocks by synchronizing their different oscillation phases. Chronobiology is the science that studies biologic rhythms exhibiting recurrent cyclic behavior. Circadian rhythms have a duration of approximately 24 h and can be assessed through chronobiologic analysis of time series of melatonin, cortisol, and temperature. Critically ill patients experience severe circadian deregulation due to not only the lack of effective timekeepers in the intensive care unit (ICU) environment but also systemic inflammation. The latter has been found in both animal and human studies to disrupt circadian rhythmicity of all measured biomarkers. The aims of this article are to describe circadian physiology during acute stress and to discuss the effects of ICU milieu upon circadian rhythms, in order to emphasize the value of considering circadian-immune disturbance as a potential tool for personalized treatment. Thus, besides neoplastic processes, critical illness could be linked to what has been referred as ‘chronomics’: timing and rhythm. In addition, different therapeutic perspectives will be presented in association with environmental approaches that could restore circadian connection and hasten physical recovery.

Trimethoprim-induced hyperkalemia in burn patients treated with intravenous or oral trimethoprim sulfamethoxazole for methicillin-resistant Staphylococcus aureus and other infections: nature or nurture?

Trimethoprim is well known to cause rashes; however, what is not commonly known is that it causes sudden and profound hyperkalemia in 10 to 20% of treated patients. The uniqueness of burn patients begs the question whether changes known to occur in these patients might also increase this trimethoprim effect. After institutional review board approval, a retrospective study evaluated 224 patients with thermal injury who had been treated with trimethoprim sulfamethoxazole (TMP-SMX), 24 of whom had underlying renal impairment (creatinine clearances <50 ml/min) and were excluded, leaving 200 patients for analysis. Three definitions of drug-induced hyperkalemia were used: 1) a ≥ 1 mEq/L rise, 2) a >0.8 mEq rise in potassium in <24 hours warranting early discontinuation of TMP-SMX, and 3) "marked" hyperkalemia defined as serum potassium of ≥ 5.5 mEq/L within 48 hours. A potassium level before trimethoprim exposure (TxK) and after TxK were collected retrospectively. Demographic data were analyzed with Student's t-test and trimethoprim dose alone, demonstrating a significant difference. Analysis of 200 patients exposed to trimethoprim demonstrated an elevation of potassium (first definition) in 31 patients (15.5%), a rapid change in serum potassium in two patients (second definition), and marked hyperkalemia (>5.5 mEq/L) in 13 patients (6.5%). Hyperkalemia never occurred in 166 of 200 patients (82%; before TxK, 3.9 ± 0.4; after TxK, 4.3 ± 0.5 mEq/L). Change in serum potassium among patients with hyperkalemia was 4.0 ± 0.5 mEq/L before TxK and 5.3 ± 0.7 mEq/L after TxK. Twelve published hyperkalemia risk factors were reviewed in these 200 patients and only history of hypertension and need for intubation was more common in those with hyperkalemia. A nearly 20% incidence of hyperkalemia and 6% serious hyperkalemia in burn patients is consistent with reports in patients without burn injury. These data also suggest that the metabolic and hormonal changes associated with burn injury do not increase further the genetically predisposed hyperkalemia resulting from exposure to trimethoprim. These data suggest patients treated with TMP-SMX should have routine serum potassium monitoring before discharge.

The concept of the immune-pineal axis tested in patients undergoing an abdominal hysterectomy

OBJECTIVE

Activation of the immune-pineal axis induces a transient reduction in nocturnal melatonin in the plasma during the proinflammatory phase of an innate immune response to allow the proper migration of leukocytes to the lesion site. This transient reduction should be regulated by inflammatory mediators, which are responsible for the fine-tuning of the process. In the present study, we measured the pre- and postoperative serum concentrations of melatonin, tumor necrosis factor (TNF) and cortisol in women who underwent an elective hysterectomy and correlated the variation in melatonin with postoperative pain.

METHODS

We evaluated 12 women who had an abdominal hysterectomy. Blood was collected at 10.00 and 22.00 h 1 week and 1 day before the surgery, on the 1st and 2nd days after the surgery and at 22.00 h on the day of the surgery.

RESULTS

On the night after the surgery, there was no melatonin detected at 22.00 h. High TNF levels were accompanied by a lower nocturnal melatonin output, higher postoperative pain according to a visual analog scale and the request of higher doses of analgesics. In addition, low cortisol levels were accompanied by a lower nocturnal melatonin output.

CONCLUSION

Our results confirm that the same antagonistic pattern between TNF and glucocorticoids observed in cultured pineal glands also occurs in humans. This integrative pattern suggests that the cross talk between the immune and endocrine system orchestrates longitudinal changes in pineal activity, reinforcing the hypothesis of an immune-pineal axis.