Sleep and psychoneuroimmunology

Restless nights when sick: ectoparasite infections alter rest-activity cycles of diurnal fish hosts

Circadian rhythms are timekeeping mechanisms responsible for an array of biological processes. Disruption of such cycles can detrimentally affect animal health. Circadian rhythms are critical in the co-evolution of host–parasite systems, as synchronization of parasite rhythms to the host can influence infection dynamics and transmission potential. This study examines the circadian rhythms in behaviour and activity of a model fish species (Poecilia reticulata) in isolation and in shoals, both when uninfected and infected with an ectoparasite (Gyrodactylus turnbulli). Additionally, the rhythmical variance of parasite activity under different light conditions as well as rhythmical variance in parasite transmissibility was explored. Overall, infection alters the circadian rhythm of fish, causing nocturnal restlessness. Increased activity of gyrodactylids on the host's skin at night could potentially contribute to this elevated host activity. Whilst migration of gyrodactylids across the host's skin may have caused irritation to the host resulting in nocturnal restlessness, the disruption in guppy activity rhythm caused by the expression of host innate immunity cannot be excluded. We discuss the wider repercussions such behavioural responses to infection have for host health, the implications for animal behaviour studies of diurnal species as well as the application of chronotherapeutic approaches to aquaculture.

The Impact of Immunotherapy on Sleep and Circadian Rhythms in Patients with Cancer

Immunotherapy has revolutionized treatments for both early and advanced cancers, and as their role evolves, their impact on sleep and circadian rhythms continues to unfold. The recognition, evaluation, and treatment of sleep and circadian rhythm disturbance leads to improved symptom management, quality of life and treatment outcomes. An intricate complex relationship exists in the microenvironment with immunity, sleep and the tumor, and these may further vary based on the cancer, addition of standard chemotherapy, and pre-existing patient factors. Sleep and circadian rhythms may offer tools to better utilize immunotherapy in the care of cancer patients, leading to better treatment outcome, reduced symptom burden, and increased quality of life.

Sleep assessment in critically ill adults: A systematic review and meta-analysis

PURPOSE

To systematically review sleep evaluation, characterize sleep disruption, and explore effects of sleepdisruption on outcomes in adult ICU patients.

MATERIALS AND METHODS

We systematically searched databases from May 1969 to June 2021 (PROSPERO protocol number: CRD42020175581). Prospective and retrospective studies were included studying sleep in critically ill adults, excluding patients with sleep or psychiatric disorders. Meta-regression methods were applied when feasible.

RESULTS

132 studies (8797 patients) were included. Fifteen sleep assessment methods were identified, with only two validated. Patients had significant sleep disruption, with low sleep time, and low proportion of restorative rapid eye movement (REM). Sedation was associated with higher sleep efficiency and sleep time. Surgical versus medical patients had lower sleep quality. Patients on ventilation had a higher amount of light sleep. Meta-regression only suggested an association between total sleep time and occurrence of delirium (p < 0.001, 15 studies, 519 patients). Scarce data precluded further analyses. Sleep characterized with polysomnography (PSG) correlated well with actigraphy and Richards Campbell Sleep Questionnaire (RCSQ).

CONCLUSIONS

Sleep in critically ill patients is severely disturbed, and actigraphy and RCSQ seem reliable alternatives to PSG. Future studies should evaluate impact of sleep disruption on outcomes.

Music intervention for sleep quality in critically ill and surgical patients: a meta-analysis

OBJECTIVE

Sleep disruption occurs frequently in hospitalised patients. Given the potential of music intervention as a non-pharmacological measure to improve sleep quality, we aimed to assess and quantify current literature on the effect of recorded music interventions on sleep quality and quantity in the adult critical care and surgical populations.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, MEDLINE Ovid, Cochrane Central, Web of Science and Google Scholar.

ELIGIBILITY CRITERIA FOR STUDIES

Randomised controlled trials assessing the effect of music on sleep quality in critically ill and surgical patients.

METHODS

The electronic databases were systematically searched from 1 January 1981 to 27 January 2020. Data were screened, extracted and appraised by two independent reviewers. Primary outcomes were sleep quality and quantity, assessed with validated tools. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Random effects meta-analysis was performed, and pooled standardised mean differences (SMDs) with 95% CIs were reported.

RESULTS

Five studies (259 patients) were included in qualitative (risk of bias) and quantitative analysis (meta-analysis). Pooled data showed a significant effect of recorded music on subjective sleep quality in the critical care and surgical population (SMD=1.21 (95% CI 0.50 to 1.91), p<0.01, excluding one non-English study; SMD=0.87 (95% CI 0.45 to 1.29), p<0.01). The SMD of 1.21 corresponded to a 27.1% (95% CI 11.2 to 42.8) increase in subjective sleep quality using validated questionnaires. A significant increase in subjective sleep quantity of 36 min was found in one study. Objective measurements of sleep assessed in one study using polysomnography showed significant increase in deeper sleep stage in the music group.

CONCLUSIONS

Recorded music showed a significant improvement in subjective sleep quality in some critical care and surgical populations. Therefore, its use may be relevant to improve sleep, but given the moderate potential for bias, further research is needed.

PROSPERO REGISTRATION NUMBER

CRD42020167783.

Uncovering the pharmacological mechanism of the effects of the Banxia-Xiakucao Chinese Herb Pair on sleep disorder by a systems pharmacology approach

Sleep disorder (SD) has a high incidence and seriously affects quality of life, mental health and even the manifestation of physical diseases. The combination of Pinellia ternata (Chinese name: banxia) and Prunella vulgaris (Chinese name: xiakucao), known as the Banxia-Xiakucao Chinese herb pair (BXHP), is a proven Chinese herbal medicine that has been used to treat SD for thousands of years due to its significant clinical effects. However, its active pharmacological components and sedative-hypnotic mechanisms have not been fully elucidated. Thus, the present study used a systematic pharmacological approach to develop pharmacokinetic screens and target predictions via construction of a protein-protein interaction network and annotation database for SD-related and putative BXHP-related targets. Visualization, screening and integrated discovery enrichment analyses were conducted. The BXHP chemical database contains 166 compounds between the two herbal ingredients, and of these, 22 potential active molecules were screened by pharmacokinetic evaluation. The targets of 114 of the active molecules were predicted, and 34 were selected for further analysis. Finally, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses suggested that BXHP can reduce inflammatory responses. and mediate immune-related and central nervous system neurotransmitters via regulation of multiple targets and pathways. The use of a systematic pharmacology-based approach in the present study further elucidated the mechanisms of action underlying BXHP for the treatment of SD from a holistic perspective and sheds light on the systemic mechanisms of action of Chinese herbal medicines in general.

Psychophysiological insomnia and respiratory tract infections: results of an infection-diary-based cohort study

STUDY OBJECTIVES

The immune theory of sleep suggests an important role of sleep for a functioning immune system. Insomnia has been associated with heightened risk for infections. The aim of the study was to test whether psychophysiological insomnia (PI) is associated with subsequent respiratory tract infections (RTIs) in the context of an infection-diary-based cohort study.

METHODS

We recruited 674 adults from a cross-sectional survey on airway infections into the airway infection susceptibility (AWIS) cohort and invited them to self-report in diaries incident RTIs experienced during 7097 months (mean of 11.9 months of completed infection diaries per individual). The Regensburg Insomnia Scale (RIS) was assessed at baseline to measure PI. As outcome, we considered an infection diary score summing up prospectively reported RTIs.

RESULTS

The RIS score correlated significantly with the infection diary score summarizing reported RTIs (correlation coefficient = 0.265, p < 0.001). Adjustments by putative confounders did only marginally affect this relationship. No significant differences in the relationship between RIS score and diary score were found for subgroups including those by gender, body mass index, perceived stress, and comorbidity. People affected by a combination of high PI and obesity were eight times more likely to belong to the group reporting the highest 10% of RTIs compared to the nonobese group with low RIS score (p < 0.001). A high RIS score in men was associated with a higher neutrophil-to-lymphocyte ratio, an indicator of inflammation.

CONCLUSIONS

Our data support the relevance of adequate sleep for an immune system ready to fight pathogens and prevent airway infections.

Sensory Hypersensitivity Predicts Reduced Sleeping Quality in Patients With Major Affective Disorders

The goal of this study was to examine the sensory profile (expressed as hypersensitivity or hyposensitivity) of patients with major affective disorders and its relative contribution to the prediction of sleep quality while considering affective temperaments and depression, which may impact sleep quality. We recruited 176 participants (mean age, 47.3 y), of whom 56.8% had a diagnosis of unipolar major depressive disorder and 43.2% a diagnosis of bipolar disorder. Reduced sleep quality was evaluated using the Pittsburgh Sleep Quality Index. Affective temperaments were assessed using the Temperament Evaluation of Memphis, Pisa, Paris and San Diego. Sensory hypersensitivity, assessed using the Adolescent/Adult Sensory Profile, significantly distinguished between poor and good sleepers. Sleep quality was mainly predicted by the Beck Depression Inventory-II total score and anxious temperament. Sensory hypersensitivity contributed to this prediction mainly with regard to sleep efficiency and related daytime dysfunction.

Rapid eye movement-sleep is reduced in patients with acute uncomplicated diverticulitis-an observational study

Introduction. Sleep disturbances are commonly found in patients in the postoperative period. Sleep disturbances may give rise to several complications including cardiopulmonary instability, transient cognitive dysfunction and prolonged convalescence. Many factors including host inflammatory responses are believed to cause postoperative sleep disturbances, as inflammatory responses can alter sleep architecture through cytokine-brain interactions. Our aim was to investigate alteration of sleep architecture during acute infection and its relationships to inflammation and clinical symptoms. Materials & Methods. In this observational study, we included patients with acute uncomplicated diverticulitis as a model to investigate the isolated effects of inflammatory responses on sleep. Eleven patients completed the study. Patients were admitted and treated with antibiotics for two nights, during which study endpoints were measured by polysomnography recordings, self-reported discomfort scores and blood samples of cytokines. One month later, the patients, who now were in complete remission, were readmitted and the endpoints were re-measured (the baseline values). Results. Total sleep time was reduced 4% and 7% the first (p = 0.006) and second (p = 0.014) nights of diverticulitis, compared to baseline, respectively. The rapid eye movement sleep was reduced 33% the first night (p = 0.016), compared to baseline. Moreover, plasma IL-6 levels were correlated to non-rapid eye movement sleep, rapid eye movement sleep and fatigue. Conclusion. Total sleep time and rapid eye movement sleep were reduced during nights with active diverticulitis and correlated with markers of inflammation.

TNFα G308A polymorphism is associated with resilience to sleep deprivation-induced psychomotor vigilance performance impairment in healthy young adults

Cytokines such as TNFα play an integral role in sleep/wake regulation and have recently been hypothesized to be involved in cognitive impairment due to sleep deprivation. We examined the effect of a guanine to adenine substitution at position 308 in the TNFα gene (TNFα G308A) on psychomotor vigilance performance impairment during total sleep deprivation. A total of 88 healthy women and men (ages 22-40) participated in one of five laboratory total sleep deprivation experiments. Performance on a psychomotor vigilance test (PVT) was measured every 2-3h. The TNFα 308A allele, which is less common than the 308G allele, was associated with greater resilience to psychomotor vigilance performance impairment during total sleep deprivation (regardless of time of day), and also provided a small performance benefit at baseline. The effect of genotype on resilience persisted when controlling for between-subjects differences in age, gender, race/ethnicity, and baseline sleep duration. The TNFα G308A polymorphism predicted less than 10% of the overall between-subjects variance in performance impairment during sleep deprivation. Nonetheless, the differential effect of the polymorphism at the peak of performance impairment was more than 50% of median performance impairment at that time, which is sizeable compared to the effects of other genotypes reported in the literature. Our findings provided evidence for a role of TNFα in the effects of sleep deprivation on psychomotor vigilance performance. Furthermore, the TNFα G308A polymorphism may have predictive potential in a biomarker panel for the assessment of resilience to psychomotor vigilance performance impairment due to sleep deprivation.

Differential activation of immune factors in neurons and glia contribute to individual differences in resilience/vulnerability to sleep disruption

Individuals frequently find themselves confronted with a variety of challenges that threaten their wellbeing. While some individuals face these challenges efficiently and thrive (resilient) others are unable to cope and may suffer persistent consequences (vulnerable). Resilience/vulnerability to sleep disruption may contribute to the vulnerability of individuals exposed to challenging conditions. With that in mind we exploited individual differences in a fly's ability to form short-term memory (STM) following 3 different types of sleep disruption to identify the underlying genes. Our analysis showed that in each category of flies examined, there are individuals that form STM in the face of sleep loss (resilient) while other individuals show dramatic declines in cognitive behavior (vulnerable). Molecular genetic studies revealed that Antimicrobial Peptides, factors important for innate immunity, were candidates for conferring resilience/vulnerability to sleep deprivation. Specifically, Metchnikowin (Mtk), drosocin (dro) and Attacin (Att) transcript levels seemed to be differentially increased by sleep deprivation in glia (Mtk), neurons (dro) or primarily in the head fat body (Att). Follow-up genetic studies confirmed that expressing Mtk in glia but not neurons, and expressing dro in neurons but not glia, disrupted memory while modulating sleep in opposite directions. These data indicate that various factors within glia or neurons can contribute to individual differences in resilience/vulnerability to sleep deprivation.

Sleep loss activates cellular inflammation and signal transducer and activator of transcription (STAT) family proteins in humans

Sleep disturbance and short sleep duration are associated with inflammation and related disorders including cardiovascular disease, arthritis, diabetes mellitus, and certain cancers. This study was undertaken to test the effects of experimental sleep loss on spontaneous cellular inflammation and activation of signal transducer and activator of transcription (STAT) family proteins, which together promote an inflammatory microenvironment. In 24 healthy adults (16 females; 8 males), spontaneous production of IL-6 and TNF-α in monocytes and spontaneous intranuclear expression of activated STAT1, STAT3, and STAT5 in peripheral blood mononuclear cells (PBMC), monocyte-, and lymphocyte populations were measured in the morning after uninterrupted baseline sleep, partial sleep deprivation (PSD, sleep period from 3a.m. to 7a.m.), and recovery sleep. Relative to baseline, spontaneous monocytic expression of IL-6 and TNF-α was significantly greater after PSD (P<0.02) and after recovery sleep (P<0.01). Relative to baseline, spontaneous monocytic expression of activated STAT1 and STAT5 was significantly greater after recovery sleep (P<0.007 and P<0.02, respectively) but not STAT3 (P=0.09). No changes in STAT1, STAT3, or STAT5 were found in lymphocyte populations. Sleep loss induces activation of spontaneous cellular innate immunity and of STAT family proteins, which together map the dynamics of sleep loss on the molecular signaling pathways that regulate inflammatory and other immune responses. Treatments that target short sleep duration have the potential to constrain inflammation and reduce the risk for inflammatory disorders and some cancers in humans.

Quality of Sleep in an HIV Population on Antiretroviral Therapy at an Urban Tertiary Centre in Lagos, Nigeria

Aim. To determine the prevalence of sleep disturbance and its associated characteristics in HIV-positive outpatients on HAART using the PSQI. Methods. Using a cross-sectional design, 300 patients attending the outpatient HIV/AIDS clinic at the Lagos State University Teaching Hospital were recruited. Baseline data obtained included the participants' demographic data, educational qualification, and marital status. Their treatment history, including duration since HIV diagnosis, the most recent CD4 cell count, and current antiretroviral therapies, was obtained from their case records. Each participant completed the PSQI questionnaire and those with scores ≥5 were diagnosed with poor sleep quality. Results. The participants were made up of 70.7% females and 29.3% males. Their ages ranged between 18 and 74 years with a mean of 38.9 ± 10.3 years. According to the PSQI, 59.3% reported poor sleep quality. The mean score of those with poor quality sleep (9.2 ± 3.3) was comparable to that of those with good quality sleep (1.26 ± 1.4). P < 0.001. Significant differences were observed in all the individual components of the PSQI (P < 0.001). On multivariate analyses, the independent associations with sleep quality were the duration since HIV diagnosis (P = 0.29), efavirenz based regimen (P < 0.001), and lower CD4 cell count (P < 0.001). Conclusions. Sleep disturbances are quite common in the HIV population even in the era of HAART. Early recognition via routine assessment and effective treatments could prevent the resultant complications and improve quality of life.

Sleep fragmentation exacerbates mechanical hypersensitivity and alters subsequent sleep-wake behavior in a mouse model of musculoskeletal sensitization

STUDY OBJECTIVES

Sleep deprivation, or sleep disruption, enhances pain in human subjects. Chronic musculoskeletal pain is prevalent in our society, and constitutes a tremendous public health burden. Although preclinical models of neuropathic and inflammatory pain demonstrate effects on sleep, few studies focus on musculoskeletal pain. We reported elsewhere in this issue of SLEEP that musculoskeletal sensitization alters sleep of mice. In this study we hypothesize that sleep fragmentation during the development of musculoskeletal sensitization will exacerbate subsequent pain responses and alter sleep-wake behavior of mice.

DESIGN

This is a preclinical study using C57BL/6J mice to determine the effect on behavioral outcomes of sleep fragmentation combined with musculoskeletal sensitization.

METHODS

Musculoskeletal sensitization, a model of chronic muscle pain, was induced using two unilateral injections of acidified saline (pH 4.0) into the gastrocnemius muscle, spaced 5 days apart. Musculoskeletal sensitization manifests as mechanical hypersensitivity determined by von Frey filament testing at the hindpaws. Sleep fragmentation took place during the consecutive 12-h light periods of the 5 days between intramuscular injections. Electroencephalogram (EEG) and body temperature were recorded from some mice at baseline and for 3 weeks after musculoskeletal sensitization. Mechanical hypersensitivity was determined at preinjection baseline and on days 1, 3, 7, 14, and 21 after sensitization. Two additional experiments were conducted to determine the independent effects of sleep fragmentation or musculoskeletal sensitization on mechanical hypersensitivity.

RESULTS

Five days of sleep fragmentation alone did not induce mechanical hypersensitivity, whereas sleep fragmentation combined with musculoskeletal sensitization resulted in prolonged and exacerbated mechanical hypersensitivity. Sleep fragmentation combined with musculoskeletal sensitization had an effect on subsequent sleep of mice as demonstrated by increased numbers of sleep-wake state transitions during the light and dark periods; changes in nonrapid eye movement (NREM) sleep, rapid eye movement sleep, and wakefulness; and altered delta power during NREM sleep. These effects persisted for at least 3 weeks postsensitization.

CONCLUSIONS

Our data demonstrate that sleep fragmentation combined with musculoskeletal sensitization exacerbates the physiological and behavioral responses of mice to musculoskeletal sensitization, including mechanical hypersensitivity and sleep-wake behavior. These data contribute to increasing literature demonstrating bidirectional relationships between sleep and pain. The prevalence and incidence of insufficient sleep and pathologies characterized by chronic musculoskeletal pain are increasing in the United States. These demographic data underscore the need for research focused on insufficient sleep and chronic pain so that the quality of life for the millions of individuals with these conditions may be improved.

Effects of music on immunity and physiological responses in healthcare workers: a randomized controlled trial

Research-based evidence supports the effectiveness of soothing music in improving stress-related psycho-physiological indices in a clinical setting. However, there is currently insufficient scientific knowledge of the effects of music on immune markers of stress in humans. Therefore, the aims of the study were to compare the effects of music and quiet rest on the levels of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interleukin-10 (IL-10), heart rate and mean arterial pressure among healthcare workers. By using a randomized controlled trial design, 60 nurses were randomly assigned to the stimulating or sedating music or rest groups for 30 min. Participants' psychoneuroimmunological parameters were measured using enzyme-linked immunosorbent assays. General estimating equation was used to analyse data. Results revealed that IL-6, TNF-α and IL-10 were not detectable in this population. No significance differences in heart rate were found among the three groups. However, the stimulating music group had significantly higher mean arterial pressure levels than the sedating music group but no differences between the quiet rest group and the sedating music group. Music with different tempi had little effect on mean arterial pressure. Any effect of music on immune markers of stress requires further research.

A randomized controlled trial of the effects of listening to non-commercial music on quality of nocturnal sleep and relaxation indices in patients in medical intensive care unit

AIM

The purpose was to examine the effects of non-commercial music on quality of sleep and relaxation indices, including heart rate, mean arterial pressure, and respiratory rate in patients in intensive care units.

BACKGROUND

There is currently insufficient scientific knowledge for the effects of music on quality of sleep in critically ill patients.

DESIGN

A randomized controlled trial.

METHODS

Between January-December 2010, 28 patients aged 39-78 years were randomly assigned to music and control groups. Participants in the music groups listened to non-commercial music for 45 minutes at nocturnal sleep time. In the control group, participants slept with no music. Participants were assessed using vital signs monitors, standardized questionnaire, and polysomnography. Polysomnography sleep was recorded for the first 2 hours of the nocturnal sleep. General estimating equation was applied to analyse data.

FINDINGS

Participants in the music group had shorter stage N2 sleep and longer stage N3 sleep in the first 2 hours of the nocturnal sleep and improved self-reported sleep quality, compared with those in the control group. The music group patients also had significantly lower heart rates than those in the control group. The intensive care units patients experienced fragmented sleep with a high frequency of awakenings and severe reduction in random eye movement sleep during the first 2 hours of the nocturnal sleep.

CONCLUSION

The findings provided evidence for nurses to use soothing music as a research-based nursing intervention for intensive care unit patients' sleep improvement.

Sleep and Immune Function

Scientists are only beginning to fully understand the purpose of sleep and its underlying mechanisms. Lack of sleep is associated with many diseases, including infection, and with increased mortality. Lack of proper sleep is an important problem in the intensive care unit, and interventions have been designed to improve it. Sleep is associated with immune function, and this relationship is partially based on the physiological basis of sleep, sleep architecture, the sleep-wake cycle, cytokines and the hypothalamic-pituitary axis.

Advances in research of sleep disturbance in patients with hepatitis C virus infection

According to the WHO statistics, approximately 171 million people are infected by hepatitis C virus (HCV) worldwide. Chronic HCV infection is associated with physical and mental symptoms including fatigue, sleep disturbance, and depression that adversely affect quality of life. But sleep disturbance has received little attention in the literature, with the exception of sleep changes noted in patients with cirrhosis and end-stage liver disease. More studies focusing on the role of chronic hepatitis C (CHC) infection in the development of sleep disorders are needed. Increased knowledge about the mechanisms behind the pathogenesis of sleep disturbance in patients with CHC will help us develop appropriate treatments.

Biological Consequences of Disturbed Sleep: Important Mediators of Health?

There is an extensive literature regarding the immunological and endocrinological consequences of illness, stress, and psychopathology. Yet only a modest literature is available regarding the potential unfavorable effects of chronic sleep loss/disruption on immune and endocrine pathways or on various aspects of health. Given that humans spend approximately 1/3 of their lives asleep, it seems pertinent to evaluate this necessary yet understudied behavior. The evidence overwhelmingly indicates that "excessive" sleep disruption or poor sleep quality/continuity may subsequently increase risk for adverse health outcomes, as well as mortality. This is thought to occur through dysregulation of biological pathways. While our information addressing the immunological or endocrinological consequences of poor sleep is mounting, the majority of evidence stems from epidemiologic and cross-sectional studies. The immune and endocrine systems are dynamic and constantly in flux. Thus, the methodologies and study designs used to understand how sleep affects these systems needs to be as dynamic. Experimental manipulations and longitudinal evaluations are needed to effectively understand sleep as a risk factor for health. Thus, this paper is a primer in which to highlight the immunological and endocrinological consequences of disrupted or disturbed sleep as well as describe how these relationships may impact overall health. It is also meant to spark an interest for future evaluations of how the behavior of sleep is relevant to health.

Inflammatory pathways in children with insufficient or disordered sleep

Sleep is not only an essential physiological function, but also serves important roles in promoting growth, maturation, and overall health of children and adolescents. There is increasing interest regarding the impact of sleep and its disorders on the regulation of inflammatory processes and end-organ morbidities, particularly in the context of metabolic and cardiovascular diseases (CVD) and their complications. Obstructive sleep apnea syndrome (OSAS) is an increasingly common health problem in children, and in the last decade, the emergence of increasing obesity rates has further led to remarkable increases in the prevalence of OSAS, along with more prominent neurocognitive, behavioral, cardiovascular and metabolic morbidities. Although the underlying mechanisms leading to OSAS-induced morbidities are likely multi-factorial, and remain to be fully elucidated, activation of inflammatory pathways by OSAS has emerged as an important pathophysiological component of the end-organ injury associated with this disorder. To this effect, it would appear that OSAS could be viewed as a chronic, low-grade inflammatory disorder. Furthermore, the concurrent presence of obesity and OSAS poses a theoretically increased risk of OSAS-related complications. In this review, we will critically review the current state of research regarding the impact of insufficient and disrupted sleep and OSAS on the immune processes and inflammatory pathways that underlie childhood OSAS as a distinctive systemic inflammatory condition in children, and will explore potential interactions between OSAS and obesity.

Higher comorbidity of depression and cardiovascular disease in women: a biopsychosocial perspective

OBJECTIVES

The present paper aims at offering a synthesis of possible reasons of the higher comorbidity of cardiovascular disease (CVD) and depression in women from a biopsychosocial perspective.

METHOD

The available literature is reviewed under sex/gender aspects related to the link between depression and CVD and common pathways to depression and CVD associated with chronic stress experiences including pathophysiological mechanisms and behavioural, cognitive, psychosocial and sociological risk factors/predictors.

RESULTS

There is considerable evidence that greater exposure to chronic stressors in women, interpersonal stress responsiveness, and internalizing coping styles are associated with an elevated risk of CVD and/or depression through behavioural and pathophysiological mechanisms including alterations in HPA axis functioning and autonomic nervous system which appear to be specific for women.

CONCLUSION

Women seem to be more strongly affected by psychosocial stressors related to CVD and depression as well as by direct and indirect effects of chronic stress compared to men. More evidence in understanding these differences within the biological, psychosocial and sociostructural determinants and pathways is essential for promoting women's health.

Naturalistic changes in insomnia symptoms and pain in temporomandibular joint disorder: a cross-lagged panel analysis

An increasing number of prospective studies suggest a bi-directional association between the pain and sleep quality. Few of these investigations have controlled for synchronous correlations, an important source of extraneous variance in lagged associations, which may have confounded conclusions of prior investigations. Despite high rates of insomnia in temporomandibular joint disorders (TMD), no studies have examined temporal associations between naturalistic fluctuations in insomnia and pain in TMD. We conducted cross-lagged panel analysis to examine reciprocal temporal associations between 1-month changes in insomnia symptom severity and self-reported pain over 3 months among 53 TMD patients. This rigorous analytic strategy represents a comprehensive method to explore possible reciprocal temporal associations between insomnia and pain that controls for both auto- and synchronous correlations. Analyses revealed that initial-month increases in insomnia were associated with next-month increases in average daily pain, but not vice versa. The direction of the effect was such that initial-month increases in insomnia symptom severity were associated with next-month increases in average daily pain. These data suggest that naturally occurring fluctuations in insomnia symptom severity are prospectively associated with fluctuations in daily pain experience for persons with TMD. Potential mechanisms by which insomnia might influence pain in TMD and therapeutic implications of these findings are discussed.