The interplay between sleep and gut microbiota.

Sleep is a universal physiological need in all species and is essential for the maintenance and recovery of various physiological functions of the body. In late years, the gut microbiota (GM), a vast and extraordinarily complex ecosystem located in human gastrointestinal tract that oversees an array of critical bodily functions, has become a popular focus among researchers. Accumulated evidences in this field have revealed that it exerts important roles in the regulation of some biological characteristics, especially metabolic, immunological and neurobehavioral functions. With the increasing comprehension of brain-gut axis, a bidirectional communication channel linking the brain and gut, the roles of GM in sleep are paid much attention to. Evidences have shown that the GM is essential for the maintenance of normal sleep physiology. In turn, it has also been demonstrated that the abnormal sleep patterns and duration affect the composition, diversity and function of the GM through the brain-gut-microbiota axis (BGMA). Present contributions have described several underlying factors that could be involved in the BGMA in sleep, such as the immune system, the vagus nerve, the neuroendocrine system, and bacterial metabolites. Furthermore, several interventions targeting the GM have been proved to be beneficial for amelioration of sleep problems. On this basis, in this review, we aim to explore the interaction between sleep and GM, and elucidate the therapeutic microbiota manipulations with potential promoting effects on sleep quality.

Dexmedetomidine alleviates neuroinflammation, restores sleep disorders and neurobehavioral abnormalities in rats with minimal hepatic encephalopathy.

The occurrence and progress of minimal hepatic encephalopathy (MHE) is closely related to the inflammatory response; however, inflammation contributes to behavioral abnormalities and sleep disorders. Dexmedetomidine has anti-inflammatory effects against various diseases. Whether dexmedetomidine improves MHE and the underlying mechanism is yet unclear. The present study aimed to explore the effects of dexmedetomidine on sleep structure, neurobehavior, and brain morphology of MHE rats and investigate its underlying mechanism. A rat MHE model was established by intraperitoneal injection of thioacetamide (TAA). Dexmedetomidine or yohimbine was administered intraperitoneally to investigate the role of α2 adrenoreceptor in the protection conferred by dexmedetomidine. The 24-h sleep, neurobehavioral changes, the liver function, blood ammonia and morphological changes of the liver and brain were assessed. Also, the microglia, astrocytes, neurons, the expression of pro-inflammatory factors (IL-1ß, TNF-α, IL-18), and NLRP3 inflammasomes were detected. The results showed that marked sleep disorders, cognitive impairment, anxiety, abnormal liver function and pathological damage of liver and brain were detected in the MHE rats. The microglia in the prefrontal cortex was highly activated along with the increased expression of pro-inflammatory factors and NLRP3 inflammasomes. Interestingly, dexmedetomidine improved above indicators, however, yohimbine significantly abolished the protection of dexmedetomidine. These findings showed that dexmedetomidine restored the changes in the sleep disorders and neurobehavior in rats and reduced brain damage. The mechanism might be partially related to the activation of α2 adrenergic receptors, reduction of neuroinflammatory response, and inhibition of the activation of microglia and NLRP3/Caspase1 signaling pathway.

Sleep disturbance in adults with chronic pruritic dermatoses is associated with increased C-reactive protein levels.

BACKGROUND: Pruritus is a common symptom that can significantly reduce quality of life through sleep disruption. OBJECTIVE: To examine features of disturbed sleep in patients with chronic pruritic dermatoses and test the hypothesis that systemic inflammation may serve as a biomarker for impaired sleep in these patients. METHODS: Cross-sectional analysis of the National Health and Nutrition Examination Survey investigating systemic inflammation using C-reactive protein (CRP) levels. Logistic regression was used to compare patients with and without sleep disturbances, adjusting for demographics (model 1) and medical comorbidities (model 2). RESULTS: Chronic pruritic dermatoses were associated with multiple sleep disturbances, including nighttime awakenings (model 1: odds ratio [OR], 1.646; 95% confidence interval [CI], 1.031-2.627; model 2: OR, 1.329; 95% CI, 0.888-1.989) and early morning awakening (model 1: OR, 1.669, 95% CI, 1.118-2.493; model 2: OR, 1.582; 95% CI, 1.008-2.481). Mean CRP levels were 52.8% higher among patients with pruritic dermatoses reporting trouble sleeping compared with those who did not (0.663 vs 0.434 mg/dL; P = .034). Trouble sleeping was also positively correlated with CRP levels (ß = 0.142, P = .025). LIMITATIONS: Potential recall bias among participants. CONCLUSIONS: In addition to confirming sleep disturbances with pruritic dermatoses, we found these disturbances are more likely to present with elevated CRP levels. Clinicians should consider the potential risk for sleep-related and cardiac comorbidities in patients diagnosed with itchy skin conditions.

A Novel Presentation of the Acute Airway: Anti-IgLON5 Disease.

Anti-IgLON5 disease is a newly discovered novel sleep disorder at the crossroads of neurology and immunology. In addition to the underlying sleep disorder, anti-IgLON5 manifests with progressive aerodigestive symptoms such as dysphagia, stridor, and vocal cord paresis in 90% cases and may present to the otolaryngologist. Herein we present a case of a patient with anti-IgLON5 disease who presented to the hospital with an acute airway including marked stridor and respiratory failure requiring intubation and subsequently a tracheostomy. Laryngoscope, 131:E724-E726, 2021.

Role of interleukin 8 in depression and other psychiatric disorders.

Low grade neuroinflammation has been suggested as one of the underlying mechanisms of many psychiatric diseases as well as cognitive disorders. Interleukin 8 (IL-8), a proinflammatory cytokine produced by many cell types including macrophage and microglia, mainly functions as a neutrophil chemoattractant in the bloodstream. IL-8 is also found in the brain, where it is released from microglia in response to proinflammatory stimuli. In this review, we highlight studies focusing on the role of IL-8 in psychiatric diseases such as major depression, bipolar disorder, schizophrenia, sleep disorder, autism spectrum disorder, anxiety disorders and dementia. Increased peripheral IL-8 levels have been reported in these diseases, particularly in schizophrenic disorder, bipolar disorder, obstructive sleep apnea and autism spectrum disorder. The literature on IL-8 and major depression is inconsistent. IL-8 has been found to be a factor associated with schizophrenic prognosis and therapeutic response, and may affect a wide range of symptomatology. Considering that the exact role of immune alterations is still under research, the success of immune-based therapies in psychiatric diseases is limited for the time being.

House Dust Mite Related Allergic Rhinitis and REM Sleep Disturbances.

PURPOSE: Sleep disturbances are common in patients with allergic rhinitis (AR). Perennial allergens like house dust mites (HDM) are difficult to avoid and have nocturnal impacts on the respiratory system and Quality of Life (QOL). The Rapid Eye Movement (REM) sleep stage is associated with memory, cognition, dreams, and overall restfulness, which can be impaired in AR patients with Sleep Disordered Breathing (SDB) even when normal all-night apnea-hypopnea (AHI) or respiratory disturbance (RDI) indices are noted on polysomnography (PSG). We hypothesized that AR HDM allergen positive patients would show REM-specific SDB reflected in their objectively elevated REM-RDI values. MATERIALS AND METHODS: This retrospective analysis of 100 patients included 47 with HDM positive allergy testing. All patients underwent PSG testing calculating the RDI during REM. Multivariate logistic regression models evaluated relationships between allergic statuses and sleep parameters while controlling for potential confounders. RESULTS: Compared with allergy negative patients, HDM allergen positive patients were significantly more likely (OR 4.29, 95%CI 1.26-14.62) to have a REM-RDI in the moderate/severe range (≥15 events/h). CONCLUSIONS: Our study highlighted the significance of respiratory allergies to HDM in patients with SDB. We revealed a significant relationship between HDM allergen positivity and SDB characterized by elevated REM-RDI regardless of all-night AHI, RDI, or REM-AHI values. Clinical implications of knowing about disturbed REM and/or HDM allergenicity include better preparation, treatment, outcomes, and QOL for allergic, SDB, and upper airway surgery patients.

Relationship between rosacea and sleep.

Rosacea is a chronic facial skin disease involved in neurovascular dysregulation and neurogenic inflammation. Behavioral factors such as stress, anxiety, depression and sleep were identified to be associated with other inflammatory skin diseases. Few studies have reported sleep status in rosacea. Aiming to investigate the relationship between rosacea and sleep, a case-control survey was conducted, enrolling 608 rosacea patients and 608 sex- and age-matched healthy controls. Sleep quality was assessed through the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Diagnosis and severity grading of rosacea were evaluated under the standard guidelines of the National Rosacea Society. More rosacea patients (52.3%, n = 318) suffered poor sleep quality (PSQI, >5) than the healthy controls (24.0%, n = 146), displaying a much higher PSQI score (rosacea vs control, 6.20 vs 3.95). There was a strong association between sleep quality and rosacea (odds ratio [OR], 3.525; 95% confidence interval [CI], 2.759-4.519). Moreover, the severity of rosacea was also associated with sleep quality (OR, 1.847; 95% CI, 1.332-2.570). Single nucleotide polymorphisms in hydroxytryptamine receptor 2A and adrenoceptor-ß1 genes, which are associated with sleep behaviour, were detected and revealed to be associated with rosacea. Furthermore, the LL-37-induced rosacea-like phenotype and sleep-deprivation mice models were applied, revealing that sleep deprivation aggravated the rosacea-like phenotype in mice, with higher expression of matrix metallopeptidase 9, Toll-like receptor 2, cathelicidin antimicrobial peptide and vascular endothelial growth factor. In conclusion, rosacea patients presented poorer sleep quality, as well as a higher propability of genetic background with sleep disturbance. In addition, poor sleep might aggravate rosacea through regulating inflammatory factors, contributing to a vicious cycle in the progression of disease.

Sleep and pain: recent insights, mechanisms, and future directions in the investigation of this relationship.

Sleep disturbances and chronic pain are considered public health concerns. They are frequently associated, and the direction of its relationship and possible mechanisms underlying it are frequently debated. The exploration of the sleep-pain association is of great clinical interest to explore in order to steer potential therapeutic avenues, accommodate the patient's experience, and adapt the common practice of health professionals. In this review, the direction between sleep-pain in adult and pediatric populations will be discussed. Moreover, the possible mechanisms contributing to this relationship as endogenous pain modulation, inflammation, affect, mood and other states, the role of different endogenous substances (dopamine, orexin, melatonin, vitamin D) as well as other lesser known such as cyclic alternating pattern among others, will be explored. Finally, directions for future studies on this area will be discussed, opening up to the addition of tools such as brain imaging (e.g., fMRI), electrophysiology and non-invasive brain stimulation techniques. Such resources paired with artificial intelligence are key to personalized medicine management for patients facing pain and sleep interacting conditions.

Sleep and inflammation: partners in sickness and in health.

The discovery of reciprocal connections between the central nervous system, sleep and the immune system has shown that sleep enhances immune defences and that afferent signals from immune cells promote sleep. One mechanism by which sleep is proposed to provide a survival advantage is in terms of supporting a neurally integrated immune system that might anticipate injury and infectious threats. However, in modern times, chronic social threats can drive the development of sleep disturbances in humans, which can contribute to the dysregulation of inflammatory and antiviral responses. In this Review, I describe our current understanding of the relationship between sleep dynamics and host defence mechanisms, with a focus on cytokine responses, the neuroendocrine and autonomic pathways that connect sleep with the immune system and the role of inflammatory peptides in the homeostatic regulation of sleep. Furthermore, I discuss the therapeutic potential of harnessing these reciprocal mechanisms of sleep-immune regulation to mitigate the risk of inflammatory and infectious diseases.

Relationship between sleep disorders and lymphocyte subsets and cytokines in patients with lung cancer.

This study aimed to investigate the relationship between sleep disorders and lymphocyte subsets and cytokines in patients with lung cancer undergoing radiotherapy, and to establish a theoretical foundation for predicting sleep disorders and preventing interventions in radiotherapy in lung cancer patients. Ninety-two patients with lung cancer requiring radiotherapy were selected as the study subjects. The patients' demographic data and disease-related conditions were investigated. Their quality of sleep was measured before radiotherapy, after two and four weeks of radiotherapy, and at the end of radiotherapy. According to the Pittsburgh Sleep Quality Index Number Table (PSQI), patients with PSQI score> 7 points were put into a sleep disorder group, and patients with PSQI score 0-7 were put into a normal sleep group. Lymphocyte subsets were enumerated and cytokine levels (IL-6, IL-1b) were measured during these four periods. The difference in sleep disorders at four weeks between patients with or without synchronous chemotherapy was statistically significant (P less than 0.05). The levels of lymphocyte subsets in the sleep disorder group and the control sleep group showed no difference in the index of lymphocyte subsets before radiotherapy. In the sleep disorder group, CD4+ cells were lower after two weeks of radiotherapy (P less than 0.05). After four weeks of radiotherapy, CD3+, CD4+, and CD16+56+ subsets were lower (P less than 0.05). At the end of radiotherapy, there was no difference in each index. There was no significant difference in IL-6 levels between the two groups before radiotherapy, after two weeks, or after four weeks (P greater than 0.05). At the end of radiotherapy, IL-6 levels in the sleep disorder group were higher than those in the control sleep group (P less than 0.05). There was no significant difference in IL-1b between the two groups (P greater than 0.05). In conclusion, monitoring of T-lymphocyte subsets and IL-6 levels in patients is enhanced during radiotherapy. Clinically effective programs of radiotherapy for lung cancer improve the body's immune status.

Objective measures of sleep in fibromyalgia syndrome: Relationship to clinical, psychiatric, and immunological variables.

We aimed to investigate the changes in the objective and subjective sleep variables during painful episodes of fibromyalgia and post-episode period, and to evaluate the impact of the sleep variables on the current clinical, psychological, and immunologic parameters. Thirty-one consecutive patients who were referred to the Erenköy Physical Therapy and Rehabilitation Polyclinic with a diagnosis of fibromyalgia were evaluated before and in the sixth week of the acute pain treatment. The sleep variables were measured by polysomnography, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale. The clinical and psychiatric assessment of patients was performed by using Fibromyalgia Impact Questionnaire; Patient Health Questionnaire-Somatic, Anxiety, and Depressive Symptoms; and Visual Analog Scale. Serum pro-inflammatory molecules were measured to evaluate the immunological status. The pain treatment significantly affected subjective sleep variables, psychiatric variables, clinical variables, and IL-6 levels. The subjective sleep parameters, clinical and psychiatric variables, and IL-6 levels were improved with pain treatment in fibromyalgia. The objective sleep variables, IL-1 and TNF-alpha levels were not significantly improved with the pain treatment, and they were not related to clinical presentation of patients with fibromyalgia. Subjective variability of sleep contributes to the clinical presentation, suggesting that the objective structure is trait-specific with IL-1 and TNF-alpha.

Increased CD4 counts, pain and depression are correlates of lower sleep quality in treated HIV positive patients with low baseline CD4 counts.

Poor sleep quality leads to increased immune activation and immune activation leads to worse sleep quality. South African HIV positive patients typically have delayed start of treatment, which has been associated with CD4+ effector T cells being more spontaneously activated in chronically treated patients. This cross-sectional study investigated whether subjective sleep quality was associated with CD4+ T lymphocyte reconstitution in treated South African HIV+ patients. One hundred and thirty-nine treated HIV+ patients (109 F, age average (SD) = 43 (9)) were recruited from Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg, South Africa. Participants completed questionnaires evaluating their subjective sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth sleepiness scale), pain, and depression severity (Beck Depression Inventory). Univariate and multivariate analyses were run to determine the correlates of sleep quality in this population. Patients had been on antiretroviral treatment for about 4 years and had increased their CD4 counts from a median at baseline of 82 to 467 cells/µL. They had overall poor sleep quality (average (SD) PSQI = 7.7 (±5), 61% reporting PSQI > 5, a marker of lower sleep quality), 41% had clinical depression (average (SD) BDI = 17 (±12)) and 55% reported pain. In two separate multivariate analyses, both the overall CD4 count increase from baseline (p = 0.0006) and higher current CD4 counts (p = 0.0007) were associated with worse sleep quality, when adjusting for depression severity (p < 0.001), daytime sleepiness (p = 0.01) and the presence of pain (p < 0.01). In this cohort of treated South African HIV positive patients, poor sleep quality was associated with higher current CD4 counts, when adjusting for depression severity, daytime sleepiness and pain. Further studies should investigate the temporal relationship between HIV-related poor sleep quality and underlying immune activation.

The Role of Inflammation in the Pain, Fatigue, and Sleep Disturbance Symptom Cluster in Advanced Cancer.

CONTEXT: Symptom researchers have proposed a model of inflammatory cytokine activity and dysregulation in cancer to explain co-occurring symptoms including pain, fatigue, and sleep disturbance. OBJECTIVES: We tested the hypothesis that psychological stress accentuates inflammation and that stress and inflammation contribute to one's experience of the pain, fatigue, and sleep disturbance symptom cluster (symptom cluster severity, symptom cluster distress) and its impact (symptom cluster interference with daily life, quality of life). METHODS: We used baseline data from a symptom cluster management trial. Adult participants (N = 158) receiving chemotherapy for advanced cancer reported pain, fatigue, and sleep disturbance on enrollment. Before intervention, participants completed measures of demographics, perceived stress, symptom cluster severity, symptom cluster distress, symptom cluster interference with daily life, and quality of life and provided a blood sample for four inflammatory biomarkers (interleukin-1ß, interleukin-6, tumor necrosis factor-α, and C-reactive protein). RESULTS: Stress was not directly related to any inflammatory biomarker. Stress and tumor necrosis factor-α were positively related to symptom cluster distress, although not symptom cluster severity. Tumor necrosis factor-α was indirectly related to symptom cluster interference with daily life, through its effect on symptom cluster distress. Stress was positively associated with symptom cluster interference with daily life and inversely with quality of life. Stress also had indirect effects on symptom cluster interference with daily life, through its effect on symptom cluster distress. CONCLUSION: The proposed inflammatory model of symptoms was partially supported. Investigators should test interventions that target stress as a contributing factor in co-occurring pain, fatigue, and sleep disturbance and explore other factors that may influence inflammatory biomarker levels within the context of an advanced cancer diagnosis and treatment.

Allergic sensitization and objective measures of sleep in urban school-aged children with asthma.

BACKGROUND: Allergic sensitization is associated with increased child asthma morbidity and decreased pulmonary function. Nocturnal symptoms and/or awakenings typically are measured by self-report from diary data, whereas objective assessments of sleep in child asthma studies are lacking. OBJECTIVE: To investigate the association between increased allergic sensitization (number of positive allergy test results measured by skin prick test or specific immunoglobulin E) and sleep outcomes (sleep efficiency, sleep duration, and mean number of awakenings measured by actigraphy) in urban schoolchildren with persistent asthma. METHODS: One hundred ninety-six children with persistent asthma (7-9 years old) attending public school in 1 of 4 large urban school districts completed allergy testing during a study clinic visit. Forced expiratory volume in 1 second was monitored at home using a handheld spirometer. Sleep outcomes were measured with a wrist Actiwatch during a 1-month period in the fall and winter seasons. RESULTS: Number of positive allergy test results significantly predicted mean sleep efficiency (P = .02), such that children with more positive test results experienced less efficient sleep. Number of positive allergy test results significantly predicted mean number of night awakenings (P = .05), such that children with more positive allergy test results experienced more night awakenings. Variability in forced expiratory volume in 1 second was a significant moderator in the association between number of positive allergy test results and variability in sleep efficiency (P = .04). Racial and ethnic differences in allergic sensitization and sleep outcomes were found between African Americans and Latinos. CONCLUSION: More positive allergy test results were associated with poorer sleep outcomes measured objectively in this sample of urban children. Implications for environmental control interventions and asthma treatments in different racial and ethnic groups are discussed.

Association of Inflammatory Cytokines With the Symptom Cluster of Pain, Fatigue, Depression, and Sleep Disturbance in Chinese Patients With Cancer.

CONTEXT: Pain, fatigue, depression, and sleep disturbance are common in patients with cancer and usually co-occur as a symptom cluster. However, the mechanism underlying this symptom cluster is unclear. OBJECTIVES: This study aimed to identify subgroups of cluster symptoms, compare demographic and clinical characteristics between subgroups, and examine the associations between inflammatory cytokines and cluster symptoms. METHODS: Participants were 170 Chinese inpatients with cancer from two tertiary hospitals. Inflammatory markers including interleukin-6 (IL-6), interleukin-1 receptor antagonist, and tumor necrosis factor alpha were measured. Intergroup differences and associations of inflammatory cytokines with the cluster symptoms were examined with one-way analyses of variance and logistic regression. RESULTS: Based on cluster analysis, participants were categorized into Subgroup 1 (all low symptoms), Subgroup 2 (low pain and moderate fatigue), or Subgroup 3 (moderate-to-high on all symptoms). The three subgroups differed significantly in Eastern Cooperative Oncology Group (ECOG) performance status, sex, residence, current treatment, education, economic status, and inflammatory cytokines levels (all P < 0.05). Compared with Subgroup 1, Subgroup 3 had a significantly poorer ECOG physical performance status and higher IL-6 levels, were more often treated with combined chemoradiotherapy, and were more likely to be rural residents. IL-6 and ECOG physical performance status were significantly associated with 1.246-fold (95% CI 1.114-1.396) and 31.831-fold (95% CI 6.017-168.385) increased risk of Subgroup 3. CONCLUSION: Our findings suggest that IL-6 levels are associated with cluster symptoms in cancer patients. Clinicians should identify patients at risk for more severe symptoms and formulate novel target interventions to improve symptom management.

Altered populations of natural killer cells, cytotoxic T lymphocytes, and regulatory T cells in major depressive disorder: Association with sleep disturbance.

A subset of individuals with major depressive disorder (MDD) have impaired adaptive immunity characterized by a greater vulnerability to viral infection and a deficient response to vaccination along with a decrease in the number and/or activity of T cells and natural killer cells (NKC). Nevertheless, it remains unclear which specific subsets of lymphocytes are altered in MDD, a shortcoming we address here by utilizing an advanced fluorescence-activated cell sorting (FACS) method that allows for the differentiation of important functionally-distinct lymphocyte sub-populations. Furthermore, despite evidence that sleep disturbance, which is a core symptom of MDD, is itself associated with alterations in lymphocyte distributions, there is a paucity of studies examining the contribution of sleep disturbance on lymphocyte populations in MDD populations. Here, we measured differences in the percentages of 13 different lymphocytes and 6 different leukocytes in 54 unmedicated MDD patients (partially remitted to moderate) and 56 age and sex-matched healthy controls (HC). The relationship between self-reported sleep disturbance and cell counts was evaluated in the MDD group using the Pittsburgh Sleep Quality Index (PSQI). The MDD group showed a significantly increased percentage of CD127low/CCR4+ Treg cells, and memory Treg cells, as well as a reduction in CD56+CD16- (putative immunoregulatory) NKC counts, the latter, prior to correction for body mass index. There also was a trend for higher effector memory CD8+ cell counts in the MDD group versus the HC group. Further, within the MDD group, self-reported sleep disturbance was associated with an increased percentage of effector memory CD8+ cells but with a lower percentage of CD56+CD16- NKC. These results provide important new insights into the immune pathways involved in MDD, and provide novel evidence that MDD and associated sleep disturbance increase effector memory CD8+ and Treg pathways. Targeting sleep disturbance may have implications as a therapeutic strategy to normalize NKC and memory CD8+ cells in MDD.