Poor sleep is associated with exaggerated cortisol response to the combined dexamethasone/CRH test in a non-clinical population

Sleep-Disturbance-Induced Microglial Activation Involves CRH-Mediated Galectin 3 and Autophagy Dysregulation

Chronic sleep disturbances (CSDs) including insomnia, insufficient sleep time, and poor sleep quality are major public health concerns around the world, especially in developed countries. CSDs are major health risk factors linked to multiple neurodegenerative and neuropsychological diseases. It has been suggested that CSDs could activate microglia (Mg) leading to increased neuroinflammation levels, which ultimately lead to neuronal dysfunction. However, the detailed mechanisms underlying CSD-mediated microglial activation remain mostly unexplored. In this study, we used mice with three-weeks of sleep fragmentation (SF) to explore the underlying pathways responsible for Mg activation. Our results revealed that SF activates Mg in the hippocampus (HP) but not in the striatum and prefrontal cortex (PFc). SF increased the levels of corticotropin-releasing hormone (CRH) in the HP. In vitro mechanism studies revealed that CRH activation of Mg involves galectin 3 (Gal3) upregulation and autophagy dysregulation. CRH could disrupt lysosome membrane integrity resulting in lysosomal cathepsins leakage. CRHR2 blockage mitigated CRH-mediated effects on microglia in vitro. SF mice also show increased Gal3 levels and autophagy dysregulation in the HP compared to controls. Taken together, our results show that SF-mediated hippocampal Mg activation involves CRH mediated galectin 3 and autophagy dysregulation. These findings suggest that targeting the hippocampal CRH system might be a novel therapeutic approach to ameliorate CSD-mediated neuroinflammation and neurodegenerative diseases.

The relationship between stress responding in family context and stress sensitivity with sleep dysfunction in individuals at clinical high-risk for psychosis

Stress and sleep have been implicated in the etiology of psychosis, and literature suggests they are closely related. Two distinct domains of stress associated with sleep dysfunction in the general population are responsivity to environmental stressors and stress sensitivity. However, to date, no research has examined relationships between these stress domains and sleep dysfunction in individuals at clinical high-risk (CHR) for psychosis. A total of 57 CHR (mean age = 18.89, SD = 1.82) and 61 healthy control (HC; mean age = 18.34, SD = 2.41) adolescents and young adults completed a measure of emerging stress intolerance. A subset of participants (CHR = 50, HC = 49) completed a measure indexing responsivity to family stressors - an integral context for this developmental stage overlapping with the psychosis-risk period. Sleep efficiency, continuity, and duration were objectively assessed by actigraphy (CHR = 38, HC = 36). Partial correlations with age and sex as covariates were conducted in both groups separately to examine relationships between stress and sleep. Results indicated that automatic maladaptive responsivity to family stressors was associated with disrupted sleep in the CHR but not HC group. Specifically, greater involuntary engagement was associated with poorer sleep efficiency (r = -.42) but not sleep continuity (r = 0.31) and duration (r = .-19). Interestingly, both adaptative and maladaptive voluntary responses to stressors (engagement and disengagement coping) were not associated with sleep. Finally, impaired stress tolerance was associated with sleep efficiency (r = -0.47), continuity (r = 0.37), and duration (r = -0.43). Taken together, findings provided important groundwork for understanding the role of the relationship between involuntary maladaptive responsivity to family stressors and stress sensitivity with sleep in psychosis etiology.

How sleep duration mediated childhood trauma and Internet addiction of the vocational college population in urban areas of south China

BACKGROUND

Internet Addiction is positively associated with a range of psychological risk factors such as childhood trauma and sleep disorders. However, it remains unclear if sleep duration mediates the association between childhood trauma and Internet addiction.

METHODS

We enrolled 14,263 students from Shenzhen Polytechnic College, China. Sleep duration, Internet addiction and childhood maltreatment were assessed in these students by self-report measures, Internet Addiction Test (IAT) and Childhood Trauma Questionnaire (CTQ), respectively. With bootstrap approach and path analysis, the mediating role of sleep duration in the association between childhood trauma and Internet addiction was analysed.

RESULTS

The Internet-addicted group exhibited a higher level of the emotional abuse (EA) score, physical abuse (PA) score, sexual abuse (SA) score, a lower level of emotional neglect (EN) score and sleep duration compared with the control group (all p < 0.001). The CTQ total score and subscores showed a positive correlation with IAT scores both for males (r = 0.199, p < 0.001 for the total score, r = 0.356, p < 0.001 for EA, r = 0.270, p < 0.001 for PA, r = 0.249, p < 0.001 for SA, and r = 0.132, p < 0.001 for PN) and females (r = 0.127, p < 0.001 for the total score, r = 0.335, p < 0.001 for EA, r = 0.187, p < 0.001 for PA, r = 0.189, p < 0.001 for SA, and r = 0.065, p < 0.001 for PN). The CTQ subcores were negatively related to sleep duration both for males (r = -0.177, p < 0.001 for EA, r = -0.180, p < 0.001 for PA and r = 0.182, p < 0.001 for SA) and females (r = -0.137, p < 0.001 for EA, r = -0.105, p < 0.001 for PA, and r = -0.182, p < 0.001 for SA) and sleep duration was negatively correlated with IAT scores both in males (r = -0.120, p < 0.001) and females (r = -0.108, p < 0.001). Further, the path analysis suggested that EA and SA mediated significantly to the Internet addiction when all types of childhood trauma were examined in one model (both p < 0.001).

CONCLUSION

In the current study, a great proportion of students met criteria for Internet addiction. Sleep duration mediated a significant proportion of the indirect effect between EA/SA and Internet addiction. The findings may help with prevention and intervention of Internet addiction in the future. The limitation of this study was that it was a cross-sectional study and not controlling for other mental disorders. Future large-scale longitudinal studies will be needed to further clarify the relationship between childhood abuse and Internet addiction and the mediation role of sleep duration.

Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of findings from scientific literature on this field are presented. There is evidence of a close relationship between HPA functional alteration and the development of neuropsychiatric disorders. Sleep disorders are the most common manifestation in several neuropsychiatric conditions, and have also been associated to cortisol alterations in both adults and children. Many studies indicate that hair cortisol constitutes a valuable tool for further contributing to existing data on salivary, plasma, or urinary cortisol concentrations in patients with sleep disorders.

The effect of sleep on the salivary cortisol response to acute stressors: a review and suggestions

There have been steadily increasing studies on the relationship between sleep and stress. However, the findings regarding the effects of sleep on the acute stress response have been inconsistent. Elevated, blunted, or unchanged salivary cortisol stress response have been reported. Therefore, this study conducted a systematic review of previous studies to provide a comprehensive summary of the factors that influence the effects of sleep on the salivary cortisol stress response. We conducted a comprehensive electronic literature search in PubMed, PsycINFO, PsycARTICLES, Web of Science, MEDLINE, and EMBASE for human studies published in English (up to June 2019). Finally, 17 articles with participants aged 6.4-72 years were included in this review. We assessed the following factors: designing factors (sleep measurement, stress induction, cortisol sampling period, and time intervals between sleep measurement and the acute stress task), analyzing factors (cortisol analysis), and participants' characteristics (age, sex, and background stress levels); subsequently, we explained conflicting findings across the current literature. Further, we provide study design, analysis, and report suggestions for optimal assessment of the effects of sleep on the acute stress response. This summary of influencing factors and suggestions for future studies could help elucidate the impact of sleep on stress and advance the field.

Effects of treatment of sleep disorders on sleep, psychological and cognitive functioning and biomarkers in individuals with HIV/AIDS and under methadone maintenance therapy

BACKGROUND

Poor sleep is a major complaint of people with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) and undergoing methadone maintenance therapy (MMT). We tested the impact of three different sleep-improving interventions (trazodone; sleep hygiene training; sleep hygiene training + trazodone) on sleep, psychological functioning and biomarkers in males with HIV and undergoing MMT.

METHODS

A total of 75 male outpatients (mean age: 39.6 years) participated in a 12 week intervention. Participants were randomly assigned to one of the following conditions: trazodone 50 mg/d (TRAZ); sleep hygiene training (SHT); sleep hygiene training and trazodone (SHT + TRAZ). At baseline, and six and 12 weeks later, participants completed questionnaires covering subjective sleep and daytime sleepiness, and symptoms of depression and anxiety. In parallel, their cognitive performance (working memory; sustained attention) was assessed. Biomarkers (cortisol, BNDF, CD4⁺) were assessed at baseline and at the end of the study.

RESULTS

Over time, sleep disturbances decreased and daytime functioning and overall sleep quality improved. More specifically, both sleep disturbances and daytime functioning improved in the two SHT conditions from baseline to week 6. Daytime functioning remained stable from week 6 to week 12. Over time, in all conditions symptoms of depression and anxiety declined from baseline to week 6 and remained lower from week 6 to week 12. Daytime sleepiness, symptoms of insomnia and sleep-disordered breathing remained unchanged. Sustained attention performance improved over time from baseline to week 6 and remained high through to week 12. Biomarkers remained unchanged.

CONCLUSIONS

In males with HIV and undergoing MMT, treating sleep disturbances over a period of six to 12 weeks had a positive impact on aspects of sleep disturbance, symptoms of depression and anxiety, and cognitive performance. The results indicate that sleep hygiene training, either as stand-alone or in combination with trazodone, can produce positive results.

Probiotics: A Dietary Factor to Modulate the Gut Microbiome, Host Immune System, and Gut-Brain Interaction

Various benefits of probiotics to the host have been shown in numerous human clinical trials. These organisms have been proposed to act by improving the balance of the gut microbiota and enhancing the production of short-chain fatty acids, as well as by interacting with host cells in the gastrointestinal tract, including immune cells, nerve cells, and endocrine cells. Although the stimulation of host cells by probiotics and subsequent signaling have been explained by in vitro experiments and animal studies, there has been some skepticism as to whether probiotics can actually interact with host cells in the human gastrointestinal tract, where miscellaneous indigenous bacteria coexist. Most recently, it has been shown that the ileal microbiota in humans after consumption of a fermented milk is occupied by probiotics for several hours, indicating that there is adequate opportunity for the ingested strain to stimulate the host cells continuously over a period of time. As the dynamics of ingested probiotics in the human gastrointestinal tract become clearer, further progress in this research area is expected to elucidate their behavior within the tract, as well as the mechanism of their physiological effects on the host.

Gender differences in the associations between types of childhood maltreatment and sleep disturbance among Chinese adolescents

BACKGROUND

To explore the association between different types of childhood maltreatment and sleep disturbance among Chinese adolescents, with a particular focus on gender differences.

METHODS

A cross-sectional study was conducted in 7 randomly selected provinces of China via the 2015 School-Based Chinese Adolescents Health Survey. Questionnaires from 153,547 students were completed and were eligible for this study. The Chinese Version of the Pittsburgh Sleep Quality Index (CPSQI) and Childhood Trauma Questionnaire-Short Form (CTQ-SF) were used to assess sleep disturbance and childhood maltreatment, respectively.

RESULTS

The prevalence of sleep disturbance among adolescents in China was 21.6%. A significantly increased risk of sleep disturbance was associated with physical abuse (aOR=1.22, 95% CI=1.21-1.24), emotional abuse (aOR=1.15, 95% CI=1.14-1.15), sexual abuse (aOR=1.16, 95% CI=1.15-1.18), physical neglect (aOR=1.04, 95% CI=1.03-1.05), and emotional neglect (aOR=1.03, 95% CI=1.02-1.03). A significant dose-response relationship was found between cumulative childhood maltreatment experiences and sleep disturbance. The interaction terms (between physical abuse/emotional abuse/sexual abuse/physical neglect/emotional neglect/number of childhood traumas and gender) were significantly associated with sleep disturbance. Further stratification analyses by gender showed that girls who reported experiencing one or more of these five types of childhood maltreatment had a higher risk of sleep disturbance than boys.

LIMITATIONS

The study only included school students, and the cross-sectional design limited our ability to make causal inferences.

CONCLUSIONS

The study findings suggest that childhood maltreatment increases the risk of sleep disturbance in adolescents. Furthermore, exposure to single and multiple types of childhood maltreatment predicts lower sleep quality in girls.

Associations Between Morning Salivary and Blood Cortisol Concentrations in Individuals With Obstructive Sleep Apnea Syndrome: A Meta-Analysis

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) may be associated with an increase in hypothalamic-pituitary-adrenocortical axis activity (HPA AA). We reviewed research comparing morning salivary and blood (serum and plasma) cortisol concentrations of individuals with OSAS to those of healthy controls.

METHODS

We made a systematic search without any restrictions of the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases for relevant articles published up to August 25, 2019.

RESULTS

Sixteen studies were analyzed in this meta-analysis; five studies compared morning salivary concentrations, five compared serum concentrations, four compared plasma cortisol concentrations, and two compared both salivary and plasma concentrations. In pediatric samples, compared to healthy controls, those with OSAS had significantly lower saliva morning cortisol concentrations (MD = -0.13 µg/dl; 95% CI: 0.21, -0.04; P = 0.003). In contrast, no significant differences were observed for serum cortisol concentrations, plasma cortisol concentrations, or salivary morning cortisol concentrations between adults with and without OSAS (p = 0.61, p = 0.17, p = 0.17).

CONCLUSION

Cortisol concentrations did not differ between adults with OSAS and healthy controls. In contrast, morning salivary cortisol concentrations were lower in children with OSAS, compared to healthy controls. Given that a reduced HPA AA is observed among individuals with chronic stress, it is conceivable that children with OSAS are experiencing chronic psychophysiological stress.

The period circadian clock 2 gene responds to glucocorticoids and regulates osteogenic capacity

Introduction

The central regulatory system that generates biological rhythms is regulated by circadian clock genes expressed by cells in the suprachiasmatic nucleus. Signals from this system are converted to adrenocortical hormones through the sympathetic nervous system and transmitted to peripheral organs. Another system releases glucocorticoids (GCs) in response to stress through the HPA-axis. Here we investigated the second messenger GC, which is shared by these systems and influences the expression of circadian clock genes of cells of the musculoskeletal system and in viable bone tissue.

Methods

We used mouse-derived cell lines, which differentiate into osteoblasts (MC3T3-E1, C2C12, and 10T1/2) as well as primary cultures of mouse osteoblasts to determine the expression levels of circadian clock genes that respond to GC. Mice (mPer2^m/m) with an inactivating mutation in the period circadian clock 2 gene (Per2) exhibit marked dysrhythmia. Here we compared the bone morphologies of mPer2^m/m mice with those of wild-type (WT) mice.

Results

The expression of major circadian clock genes was detected in each cell line, and their responsiveness to GC was confirmed. We focused on Per2, a negative regulator of the circadian clock and found that a Per2-loss-of-function mutation increased the proliferative capacity of osteoblasts. Treatment of mutant mice with slow-release GC and bisphosphonate affected the maturation of bone tissue, which reflects a tendency to retard calcification.

Conclusion

Our investigations of the mechanisms that regulate circadian rhythm function in tissues of the musculoskeletal system that respond to the stress hormone GC, reveal that Per2 is required for the maturation of bone tissue. Thus, the influences of the systems that control circadian rhythms and the responses to stress by regenerating tissue used for regenerative medicine must be considered and studied in greater detail.

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Circadian clock genes expressed in musculoskeletal cells respond to GCs.

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Per2, a negative regulatory gene, influences the proliferation of osteoblasts.

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Circadian rhythms and GCs affect bone maturation and may control regenerating tissues.

Sleep Disturbances and Modulations in Inflammation: Implications for Pregnancy Health

When a woman becomes pregnant, there is a vast series of physiological, vascular, and psychological changes. Among the most commonly reported changes are those involving sleep. Pregnant women report that their ability to maintain sleep and acquire continuous refreshing sleep is impaired during the perinatal period as compared to the non-pregnant period. A growing literature supports the hypothesis that disturbed sleep (which comes in many forms) during the perinatal period is associated with an increased risk of adverse maternal, delivery, and infant outcomes. Among the suggested biological pathways linking sleep and adverse outcomes are disturbances in the immune and hormonal systems. The following paper will discuss (1) the various sleep processes that are commonly disturbed during the perinatal period and the methods used to collect sleep data; (2) the evidence linking sleep to adverse outcomes; and (3) how one specific biological pathway, the immune system, likely mediates these associations. The goal of this paper is to clarify the role that sleep disturbance has during pregnancy.

Cortisol Impacted on Explicit Learning Encoding, but Not on Storage and Retrieval, and Was Not Associated With Sleep Patterns-Results From the Trier Social Stress Test for Children (TSST-C) Among 9-Years Old Children

Background: Learning is the relatively permanent change of behavior as a result of experience and tightly related to memory and cognition. Learning is particularly important for children. Further, restoring sleep is associated both with improved learning performance and lower cortisol levels as a proxy of the so-called hypothalamus-pituitary-adrenocortical axis activity (HPA-AA). With the present study, we investigated, if and to what extent explicit learning performance was associated with cortisol levels at baseline and under challenge conditions and with objective sleep dimensions among 9-years old children.

Methods: A total of 39 children (mean age = 9.5 years; 39% females) took part in the study. Verbal and figural working and long-term memory were tested before and after the Trier Social Stress Test for Children (TSST-C). Further, children underwent sleep-EEG assessment, and cortisol awakening response (CAR) was assessed.

Results: Higher cortisol levels were associated with lower explicit learning encoding (verbal, but not figural learning). Higher verbal and figural working and long-term memory performance predicted lower cortisol secretion under the TSST-C, along with higher verbal and figural working and long-term memory performance after the TSST-C. Cognitive test performances were not mediated by cortisol secretion under the TSST-C. Cognitive performance, cortisol secretion under challenge (TSST-C) and basal conditions (morning) and sleep patterns were unrelated.

Conclusions: The pattern of results suggests that among a sample of 9-years old children cortisol secretion and stages of memory processes (encoding, storage, retrieval) are associated in a complex and bi-directional way. Further, it appears that cognitive-emotional processes underlying cognitive performance and its evaluation might impact on subsequent cortisol secretion as a proxy of neuroendocrinological response to cognitive-emotional processes. Last, cognitive performance and cortisol secretion under challenge conditions were not related to objective sleep patterns and baseline cortisol secretion.

Glucocorticoid and inflammatory reactivity to a repeated physiological stressor in insomnia disorder

Despite known associations of insomnia disorder with alterations in cytokine and glucocorticoid (GC) production, neither the sensitivity of immune cells to a GC signal nor the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis and inflammatory system to stress, or adaptation of these systems to repeated stress have been assessed in patients with insomnia. To investigate potential dysregulation in stress reactivity and adaptation to repeated exposure, a physiological stressor (the cold pressor test; CPT) was repeatedly administered to N = 20 participants with insomnia disorder (based on DSM-V, 18 females, age 30 ± 2.5 years) and N = 20 sex-matched healthy controls following an at-home actigraphy and in-laboratory PSG. HPA and inflammatory markers (serum cortisol, plasma interleukin [IL]-6) were measured at baseline/resting levels and following each of the three CPTs. In addition, sensitivity of monocytes to the synthetic GC dexamethasone was assessed in-vitro at baseline levels in order to examine the cortisol-IL-6 interplay at the cell level. Compared to healthy controls, individuals with insomnia disorder exhibited shorter sleep duration as assessed by actigraphy and PSG (p ≤ 0.05). HPA, but not inflammatory reactivity to the repeated CPT challenge was greater in insomnia disorder (p ≤ 0.05 for group effect), due to greater cortisol responses to the initial CPT (p ≤ 0.05). There were no between-group differences in the ability of the HPA to adapt to stress repetition nor in basal/resting levels of cortisol, IL-6, and GC sensitivity. These findings suggest that insomnia disorder potentiates HPA axis reactivity to initial/novel stressors, which may constitute a pathway underlying adverse health consequences in the long term.

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Insomnia disorder potentiates HPA, but not inflammatory reactivity to a novel stressor.

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The ability of the HPA axis to adapt to the repeated exposure to the same stressor is unchanged in insomnia.

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Basal/resting levels of cortisol, IL-6, and their interplay at cell level (i.e., GC sensitivity of monocytes) are unchanged in insomnia.

Beneficial effects of Lactobacillus casei strain Shirota on academic stress-induced sleep disturbance in healthy adults: a double-blind, randomised, placebo-controlled trial

The present study examined whether Lactobacillus casei strain Shirota (LcS) improves sleep quality under psychological stress. A double-blind, placebo-controlled trial was conducted in healthy 4^th year medical students exposed to academic examination stress. The trial was repeated over two consecutive years in different groups of students, and the data were pooled. For 8 weeks prior to and 3 weeks after a national standardised examination, a total of 48 and 46 subjects received a daily dose of 100 ml of LcS-fermented milk or non-fermented placebo milk, respectively. Study measures included subjective anxiety, overnight single-channel electroencephalography (EEG) recordings, and the Oguri-Shirakawa-Azumi (OSA) sleep inventory scores of subjective sleep quality. Total OSA scores were significantly lower than baseline on the day before the exam and recovered after the exam, indicating a stress-induced decline in sleep quality. There was a significant positive effect of LcS treatment on OSA factors for sleepiness on rising and sleep length. Sleep latency measured by EEG lengthened as the exam approached in the placebo group but was significantly suppressed in the LcS group. The percentage of stage 3 non-REM (N3) sleep decreased in the placebo group as the exam approached, whereas it was maintained in the LcS group throughout the trial. Delta power during the first sleep cycle, measured as an index of sleep intensity, increased as the exam approached in the LcS group and was significantly higher than in the placebo group. These findings suggest that daily consumption of LcS may help to maintain sleep quality during a period of increasing stress. The observed retention of N3 sleep and increased delta power in the LcS group may have contributed to higher perceived sleep satisfaction.

Diurnal Hypothalamic-Pituitary-Adrenal Axis Measures and Inflammatory Marker Correlates in Major Depressive Disorder

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory systems is a consistent finding in patients with Major Depressive Disorder (MDD). Cortisol is often assessed by measurement of the cortisol awakening response (CAR) and/or diurnal cortisol levels. Some methods of cortisol measurement overestimate cortisol concentration due to detection of other glucocorticoids including the relatively inert cortisone, therefore this study aimed to assess the presence of both cortisol and cortisone, and the cortisol-cortisone catalyzing enzyme 11β-hydroxysteroiddehydrogenase type 1 (11β-HSD1), in depressed patients and controls. Because the HPA axis is known to regulate the body’s immune system, relationships between measures of cytokines and cortisol were also assessed. Saliva samples were collected from 57 MDD patients and 40 healthy controls at five post-wakening time points (0, +30, +60, +720 and +750 min). Glucocorticoid concentrations were measured by liquid chromatography mass spectrometry. Whole blood mRNA expression of several inflammatory markers was measured by quantitative polymerase chain reaction. This study replicated the common finding of elevated morning cortisol and reduced CAR reactivity in MDD and found no differences in cortisone or 11β-HSD1 mRNA measures. There was a negative association between interleukin 1-β (IL-1β) mRNA and morning cortisol reactivity within the depressed group, indicating that dysregulation of the HPA axis and immune system may be interconnected.

Poor Sleep Is Related to Lower Emotional Competence Among Adolescents

The aim of the present study was to explore the association between subjective insomnia and self-reported emotional competence in areas such as regulating and perceiving one's own emotions and empathy, in a sample of adolescents. Gender differences were also explored. 366 adolescents in 10th to 12th grade (mean age: M = 16.9 years) took part in this cross-sectional study. They completed questionnaires related to emotional competencies, empathy, and sleep. Higher scores for insomnia were associated with lower scores for some aspects of emotional competence and empathy. Compared to males, females generally had higher scores for emotional competence. Poor sleep as subjectively experienced among adolescents is associated with specific impairments in emotional competence and empathy. Gender-related patterns were also observed.

24-h activity rhythm and sleep in depressed outpatients

Disturbances in sleep and circadian rest-activity rhythms are key features of depression. Actigraphy, a non-invasive method for monitoring motor activity, can be used to objectively assess circadian rest-activity rhythms and sleep patterns. While recent studies have measured sleep and daytime activity of depressed patients using wrist-worn actigraphy, the actigraphic 24-h rest-activity rhythm in depression has not been well documented. We aimed to examine actigraphically measured sleep and circadian rest-activity rhythms in depressed outpatients. Twenty patients with DSM-IV major depressive episode and 20 age- and sex-matched healthy controls participated in this study. Participants completed 7 consecutive days of all-day actigraphic activity monitoring while engaging in usual activities. For sleep parameters, total sleep time, wake after sleep onset, and sleep fragmentation index were determined. Circadian rhythms were estimated by fitting individual actigraphy data to a cosine curve of a 24-h activity rhythm using the cosinor method, which generated three circadian activity rhythm parameters, i.e., MESOR (rhythm-adjusted mean), amplitude, and acrophase. Subjective sleep was also assessed using a sleep diary and the Pittsburgh Sleep Quality Index. Patients showed significantly lower MESOR and more dampened amplitude along with significant sleep disturbances. Logistic regression analysis revealed that lower MESOR and more fragmented sleep emerged as the significant predictors of depression. Correlations between subjectively and actigraphically measured parameters demonstrated the validity of actigraphic measurements. These results indicate marked disturbances in sleep and circadian rest-activity rhythms of depression. By simultaneously measuring sleep and rest-activity rhythm parameters, actigraphy might serve as an objective diagnostic aid for depression.

Sleep quality in healthy and mood-disordered persons predicts daily life emotional reactivity

Disordered sleep has been linked to impaired emotional functioning in healthy and depressed individuals. Little is known, however, about how chronic sleep problems influence emotional reactivity in everyday life. Participants with major or minor unipolar depressive disorder (n = 60) and healthy controls (n = 35) reported on sleep and emotional responses to daily life events using a computerised Experience Sampling Method. We examined whether impaired sleep quality influenced emotional reactivity to daily events, and if this relationship was altered by unipolar mood disorders. Among healthy individuals, sleep difficulties were associated with enhanced negative affect (NA) to unpleasant events and a dulled response to neutral events. However, among mood-disordered persons, sleep difficulties were associated with higher NA across all types of everyday life events. Impaired sleep quality differentially affects daily life emotional reactions as a function of depression.

Poor sleep as a pathophysiological pathway underlying the association between stressful experiences and the diurnal cortisol profile among children and adolescents

Recent evidence suggests that poor sleep is a potential pathway underlying the association between stressful experiences and the diurnal cortisol profile. However, existing findings are largely limited to adults. The present study examines whether poor sleep (duration, quality) mediates the relation between stressful experiences and the diurnal cortisol profile in children and adolescents. Children and adolescents (N = 220, M(age) = 12.62) provided six saliva samples over two days to derive cortisol indices (bedtime, AUCAG, AUCTG, slope(MAX)). Perceived stress, stressful life events, self-reported sleep duration, and sleep quality were measured. Using bootstrapping analyses, sleep quality mediated the relation between perceived stress and AUCTG (R(2) = 0.10, F(7, 212) = 3.55, p = .001; 95% BCI[0.09, 1.15]), as well as the relation between stressful life events and AUCTG (R(2) = 0.11, F(7, 212) = 3.69, p = .001; 95% BCI[0.40, 3.82]). These mediation models remained significant after adjusting for sleep duration, suggesting that poor sleep quality underlies the association between stressful experiences and the diurnal cortisol profile in children and adolescents. Longitudinal data combined with objectively-measured sleep is essential to further disentangle the complex association between sleep and stress.

Correlates of self-reported sleep duration in middle-aged and elderly Koreans: from the Health Examinees Study

Though various factors related to fluctuations in sleep duration have been identified, information remains limited regarding the correlates of short and long sleep duration among the Korean population. Thus, we investigated characteristics that could be associated with short and/or long sleep duration among middle-aged and elderly Koreans. A total of 84,094 subjects (27,717 men and 56,377 women) who participated in the Health Examinees Study were analyzed by using multinomial logistic regression models. To evaluate whether sociodemographic factors, lifestyle factors, psychological conditions, anthropometry results, and health conditions were associated with short and/or long sleep duration, odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with sleep duration of 6-7 hours as the reference group, accounting for putative covariates. Regardless of sexual differences, we found that adverse behaviors and lifestyle factors including low educational attainment, unemployment, being unmarried, current smoking status, lack of exercise, having irregular meals, poor psychosocial well-being, frequent stress events, and poor self-rated health were significantly associated with abnormal sleep duration. Similarly, diabetes mellitus and depression showed positive associations with abnormal sleep duration in both men and women. Our findings suggest that low sociodemographic characteristics, adverse lifestyle factors, poor psychological conditions, and certain disease morbidities could be associated with abnormal sleep duration in middle-aged and elderly Koreans.

Sleep and 24-h activity rhythms in relation to cortisol change after a very low-dose of dexamethasone

The hypothalamic-pituitary-adrenal (HPA) axis plays an important role in sleep. Nevertheless, the association of sleep and its 24-h organization with negative feedback control of the HPA axis has received limited attention in population-based studies. We explored this association in 493 middle-aged persons of the Rotterdam Study, a large population-based study (mean age 56 years, standard deviation: 5.3 years; 57% female). The negative feedback of the HPA axis was measured as the change in morning saliva cortisol after the intake of 0.25mg dexamethasone the night before. Actigraphy allowed us to measure the stability and fragmentation of the activity rhythm and to estimate total sleep time, sleep onset latency and wake after sleep onset. A sleep diary kept during the week of actigraphy was used to assess self-reported total sleep time, sleep onset latency, number of awakenings and perceived sleep quality. In our study, enhanced negative feedback of the HPA axis was found in association with unstable activity rhythms (B=0.106, 95% confidence interval (CI): 0.002; 0.210), total sleep time (B=0.108, 95%CI: 0.001; 0.215) and poor subjective sleep quality (B=0.107, 95%CI: 0.009; 0.206) after multivariate adjustment. These results indicated that the 24-h organization, duration and experience of sleep are all associated with the negative feedback control of the HPA axis.

Compared to controls, patients with ruptured aneurysm and surgical intervention show increase in symptoms of depression and lower cognitive performance, but their objective sleep is not affected

OBJECTIVES

Patients with aneurysmal subarachnoid haemorrhage (aSAH) have impaired sleep and cognitive performance together with more difficulties in social and everyday life. Hypocortisolism has also been reported. However, a study assessing all dimensions between aSAH severity, objective and subjective sleep, cortisol secretion, cognitive performance and social and everyday life has not so far been performed. The aim of the present study was therefore two-fold: (1) to assess, in a sample of patients with aSAH, objective and subjective sleep, cognitive functioning, social skills and cortisol secretion concurrently, and (2) to compare patients on these variables with a control group.

METHODS

Twenty-one patients (17 females; mean age: 58.80 years) with ruptured aneurysm and surgical intervention and 21 (14 females; mean age: 58.90 years) age- and gender-matched controls took part in the study. Assessments covered objective sleep-EGG recordings, subjective sleep, salivary cortisol analysis, and psychological functioning including memory performance, mood, and emotion recognition.

RESULTS

Compared to healthy controls, patients had lower scores for verbal memory performance and emotion recognition; they also reported more marked depressive symptoms and complained of poor sleep. However, no differences were found for objective sleep or cortisol secretion. Subjective and objective sleep, cortisol secretion and psychological functioning were unrelated.

CONCLUSIONS

Findings indicate that patients with aSAH face psychological rather than physiological issues.

Associations between infants' crying, sleep and cortisol secretion and mother's sleep and well-being

BACKGROUND

Infants' continuous crying is a challenge both for the child and the principal caregiver. However, the links between infants' sleep, crying and cortisol secretion and mothers' well-being and sleep have been scarcely investigated. The aim of the present study was therefore to examine the link between cortisol secretion, crying and sleep of infants characterized by infantile colic (IC) and mothers' psychological well-being and own sleep.

METHODS

Mothers of 24 infants characterized by IC (mean age = 8 weeks, SD = 1.5 weeks) completed a series of questionnaires regarding the infant's crying and sleeping patterns. Infants' sleep was objectively assessed with actigraphs. Cortisol secretion was measured by means of saliva samples in the mornings after waking. After 4 weeks, infants were assessed once again. Mothers completed questionnaires assessing their psychological well-being (depressive symptoms, family strain) and sleep.

RESULTS

Mothers' psychological well-being and sleep was greatly predicted by infants' morning saliva cortisol levels, sleep disruptions and crying intensity, whereas infants' crying duration and volume had low predictive value.

CONCLUSIONS

Mothers with infants characterized by IC are at increased risk for reporting impaired sleep, developing depressive symptoms and reporting higher family strain. Most importantly, this risk seems to be greater if their infants' sleep is fragmented.

Fighting insomnia and battling lethargy: the yin and yang of palliative care

There is an interdependent relationship between insomnia and fatigue in the medical literature, but both remain distinct entities. Insomnia entails problematic sleep initiation, maintenance, or restoration with an accompanying decrease in perceived daytime function. Lethargy is a symptom that has a wide differential diagnosis that heavily overlaps with cancer-related fatigue; however, insomnia may contribute to worsened fatigue and lethargy in cancer patients. Insomnia is a major risk factor for mood disturbances such as depression, which may also contribute to lethargy in this at-risk population. The pathophysiology of fatigue and insomnia is discussed in this review, including their differential diagnoses as well as the emerging understanding of the roles of neurotransmitters, branched-chain amino acids, and inflammatory cytokines. Treatment approaches for insomnia and fatigue are also discussed and reviewed, including the role of hypnotics, psychotropics, hormonal agents, and alternative therapies.

In pre-school children, sleep objectively assessed via actigraphy remains stable over 12 months and is related to psychological functioning, but not to cortisol secretion

STUDY OBJECTIVES

Studies of the long-term stability of sleep in pre-schoolers are scarce. The aim of the present study was to investigate objectively assessed sleep via actigraphy in pre-schoolers longitudinally, and to predict sleep, psychological functioning and cortisol secretion prospectively as a function of sleep 12 months earlier.

METHOD

A total of 73 pre-schoolers (mean age: 5.45 years; 53% females) were assessed again after 12 (mean age: 6.4 years). Sleep-actigraphy recordings were performed, saliva cortisol was analysed, and parents and experts rated children's psychological functioning.

RESULTS

Longitudinally, poor sleep at age 5.45 years was associated with poor sleep and internalizing and peer problems but not with externalizing problems and hyperactivity, and cortisol secretion 12 months later. At age 6.4 years and cross-sectionally, poor sleep was concurrently associated with greater psychological difficulties and increased cortisol secretion.

CONCLUSION

In pre-schoolers, poor sleep objectively assessed at age five was associated with psychological difficulties and poor sleep as assessed via actigraph and one year later. Results indicate that in pre-schoolers sleep remains stable over a 12-mont interval. Pre-schoolers with poor sleep appear to be at risk for developing further psychological difficulties.

Psychological coping in depressed outpatients: association with cortisol response to the combined dexamethasone/CRH test

BACKGROUND

Depression is associated with dysfunctional coping styles and dysregulated hypothalamic-pituitary-adrenal (HPA) axis function. Studies have shown that maladaptive coping strategies relate to abnormal HPA axis function; however, such a relationship has been under-studied in patients with depression. We aimed to examine whether dysfunctional coping styles in depression would be associated with abnormal cortisol reactivity.

METHODS

Seventy-four outpatients with major depressive disorder and 133 age- and sex-matched healthy individuals were recruited. Coping was assessed by the Ways of Coping Checklist. Psychological distress was assessed by the Hopkins Symptom Checklist. Cortisol reactivity was measured by the combined dexamethasone/corticotropin-releasing hormone test.

RESULTS

Compared to healthy individuals, depressed patients demonstrated significantly less use of problem-solving, positive reappraisal and social support coping styles and more use of self-blame and wishful thinking styles. Such a pattern of coping styles was significantly associated with patients' greater distress. Partial correlation analysis in patients, controlling for age and sex, revealed a significant correlation between more use of escape-avoidance coping and lower levels of reactive cortisol measures. A stepwise multiple regression analysis predicting cortisol reactivity from age, sex, distress, symptom severity and coping styles revealed that escape-avoidance coping was a significant predictor.

LIMITATIONS

The neuroendocrine challenge test was administered only once, based on a simple test protocol.

CONCLUSIONS

More use of escape-avoidance coping in depressed patients was associated with less cortisol reactivity. Our findings shed light on the heterogeneity of depression in terms of low and high levels of avoidance associated with exaggerated and blunted HPA axis reactivity, respectively.

In pre-school children, sleep objectively assessed via sleep-EEGs remains stable over 12 months and is related to psychological functioning, but not to cortisol secretion

STUDY OBJECTIVES

Cross-sectional studies provide evidence that in pre-schoolers poor sleep is by this age already associated with both poor psychological functioning and an increased cortisol secretion. However, long-term studies on the stability of sleep in pre-schoolers are scarce. The aim of the present study was therefore to investigate objectively assessed sleep in pre-schoolers longitudinally, and to predict sleep, psychological functioning and cortisol secretion prospectively as a function of sleep 12 months earlier.

METHOD

A total of 58 pre-schoolers (mean age: 5.43 years; 47% females) were re-assessed 12 months later (mean age: 6.4 years). Sleep-EEG recordings were performed, saliva cortisol was analysed, and parents and experts rated children's psychological functioning.

RESULTS

Longitudinally, poor objective sleep at age 5.4 years was associated with poor objective sleep and psychological difficulties but not cortisol secretion 12 months later. At age 6.4 years, poor sleep was concurrently associated with greater psychological difficulties and increased cortisol secretion.

CONCLUSION

In pre-schoolers, poor sleep objectively assessed at the age of 5.4 years was associated with poor sleep and psychological difficulties one year later. Data indicate that in pre-schoolers, sleep remains stable over a 12-months-period. Pre-schoolers with poor sleep appear to be at risk for developing further psychological difficulties.

Sleep and its Relationship to Racial and Ethnic Disparities in Cardiovascular Disease

There are substantial racial/ethnic disparities in cardiovascular disease in the U.S., but few mechanisms have emerged as feasible intervention targets. A growing body of research suggests that racial/ethnic differences in sleep deficiency, including extreme sleep duration, sleep-disordered breathing, and insomnia, may help explain disparities in cardiovascular disease. However, little is known about the mechanisms underlying racial/ethnic disparities in sleep. In this article, we review the extant literature on sleep and cardiovascular outcomes (e.g., hypertension, stroke, cardiovascular disease) and racial/ethnic differences in these relations. We also discuss possible mechanisms that might help explain racial/ethnic sleep disparities, including neighborhood disadvantage, psychosocial and occupational stressors, acculturation, and treatment access and adherence. More research is needed to establish causal linkages among race/ethnicity, sleep, and these mechanisms, but existing evidence suggests that targeting these factors in interventions may reduce racial/ethnic sleep disparities and improve primary prevention of cardiovascular disease among all racial/ethnic groups.

Resting state functional MRI connectivity predicts hypothalamus-pituitary-axis status in healthy males

Homeostasis of the human stress response system is critically maintained by a hierarchical system of neural and endocrine elements for which intact negative feedback is important to prevent maladaptation towards stress. Such feedback is efficiently probed by the established combined dexamethasone-suppression/corticotropin-releasing hormone stimulation (dex/CRH) test. Here we investigate which suprahypothalamic networks might modulate the response assessed by this neuroendocrine test. Combined resting state fMRI (rs-fMRI)/EEG was acquired in 20 healthy male volunteers along with dex/CRH profiles obtained on a different day outside the scanner. Seed-based network analysis and inter-seed cross correlation analysis for selected atlas-based limbic, paralimbic and medial prefrontal cortex seeds were correlated with stimulated cortisol and adrenocorticotropin hormone (ACTH) concentrations. Lower connectivity between a left hippocampus-based network and the right hippocampus significantly predicted stimulated cortisol concentration (R(2)=0.70, corrected pcluster=0.001). Six further significantly negative correlations were detected mainly in the left anterior cingulate cortex (ACC) and the medial prefrontal cortex (mPFC). The strongest positive correlation with stimulated hormone concentration was detected for the left subcallosal ACC (ACTH, R(2)=0.57, corrected pcluster=0.009). Inter-seed connectivity mainly pointed to hippocampal/amygdala interactions as correlates of the dex/CRH response. In conclusion, resting state functional connectivity patterns of limbic, particularly hippocampal, as well as cingulate and medial prefrontal areas can explain some of the variance of the dex/CRH test in healthy subjects. Functional connectivity analysis can be considered useful to study supra-hypothalamic control systems of the HPA axis.

Relationship of temperament and character with cortisol reactivity to the combined dexamethasone/CRH test in depressed outpatients

BACKGROUND

Evidence shows that depression is associated with hypothalamic-pituitary-adrenal (HPA) axis hyperactivation, although such findings are not entirely unequivocal. In contrast, various psychiatric conditions, including atypical depression, are associated with hypocortisolism. Another line of research has demonstrated that personality is associated with HPA axis alteration. It is thus hypothesized that different personality pathology in depression would be associated with distinct cortisol reactivity.

METHODS

Eighty-seven outpatients with DSM-IV major depressive disorder were recruited. Personality was assessed by the temperament and character inventory (TCI). HPA axis reactivity was measured by the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test. According to our previous studies, two subgroups were considered based on their cortisol responses to the DEX/CRH test: incomplete-suppressors whose cortisol response was exaggerated and enhanced-suppressors whose cortisol response was blunted.

RESULTS

The analysis of covariance, controlling for age, gender and symptom severity, revealed that incomplete-suppressors scored significantly higher on cooperativeness than enhanced-suppressors (p=0.002). A multivariate stepwise logistic regression analysis predicting the cortisol suppression pattern from the seven TCI dimensions, controlling for age, gender and symptom severity, revealed that lower cooperativeness (p=0.001) and higher reward dependence (p=0.018) were significant predictors toward enhanced suppression.

LIMITATIONS

The neuroendocrine challenge test was administered only once, based on a simple test protocol.

CONCLUSIONS

Our findings suggest that (personality-related) subtypes of depression might be differentiated based on the different pattern of cortisol reactivity. Future studies are warranted to further characterize the HPA axis alteration in relation to various subtypes of depression.

The Hypothalamic-Pituitary-Adrenal Axis, Obesity, and Chronic Stress Exposure: Sleep and the HPA Axis in Obesity

Obesity, exposure to stress and inadequate sleep are prevalent phenomena in modern society. In this review we focus on their relationships and critically evaluate causality. In obese individuals, one of the main stress systems, the hypothalamic-pituitary-adrenal axis, is altered, and concentrations of cortisol are elevated in adipose tissue due to elevated local activity of 11β-hydroxysteroid dehydrogenase (HSD) type 1. Short sleep and decreased sleep quality are also associated with obesity. In addition, experimental sleep curtailment induces HPA-axis alterations which, in turn, may negatively affect sleep. These findings implicate that obesity, stress and sleep loss are all related in a vicious circle. Finally, we discuss new strategies to combat obesity through modulating cortisol levels in adipose tissue by 11β-HSD(1) inhibitors or by improving sleep duration.

Pre-schoolers suffering from psychiatric disorders show increased cortisol secretion and poor sleep compared to healthy controls

BACKGROUND

Various studies of child cortisol secretion and sleep show a close association between poor sleep, deterioration of the HPA axis and unfavorable psychological functioning. However, there is little evidence as to whether these associations are clearly present in pre-school children suffering from psychiatric disorders.

METHOD

A total of 30 pre-schoolers suffering from psychiatric disorders (anxiety, adjustment disorders, emotional and attachment disorder; hyperactivity or oppositional disorder) and 35 healthy controls took part in the study. Saliva cortisol secretion was assessed both at baseline and under challenge conditions. Sleep was assessed via activity monitoring for seven consecutive days and nights, using a digital movement-measuring instrument. Parents and teachers completed questionnaires assessing children's cognitive, emotional and social functioning. The Berkeley Puppet Interview provided child-based reports of cognitive-emotional processes.

RESULTS

Compared to healthy controls, children suffering from psychiatric disorders had much higher cortisol secretion both at baseline and under challenge conditions. Sleep was also more disturbed, and parents and teachers rated children suffering from psychiatric disorders as cognitively, emotionally and behaviorally more impaired, relative to healthy controls. Children with psychiatric disorders reported being more bullied and victimized.

CONCLUSIONS

In five-year old children the presence of psychiatric disorders is reflected not only at psychological, social and behavioral, but also at neuroendocrine and sleep-related levels. It is likely that these children remain at increased risk for suffering from psychiatric difficulties later in life.

Poor sleep quality and exaggerated salivary cortisol reactivity to the cold pressor task predict greater acute pain severity in a non-clinical sample

Poor sleep is often independently associated with greater pain sensitivity and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis (e.g., greater basal cortisol and exaggerated stress-induced cortisol reactivity). However, the interactions among sleep, pain, and the HPA axis have not been adequately evaluated. In this study, 40 healthy adults provided self-report regarding perceived sleep quality over the past month prior to completion of an acute noxious physical stressor (i.e., cold pressor task; CPT). Following the CPT, they reported on the severity of pain experienced. Salivary cortisol was sampled before, immediately following, and during recovery from CPT. Using bootstrapped confidence intervals with a bias correction, results showed that poor sleep quality was significantly associated with greater reports of CPT-induced pain severity and greater cortisol reactivity (i.e., increase from baseline). Furthermore, greater cortisol reactivity to the CPT was found to significantly mediate the relationship between poor sleep and pain severity.

Modulation of cortisol responses to the DEX/CRH test by polymorphisms of the interleukin-1beta gene in healthy adults

BACKGROUND

Recently, hypothalamus-pituitary-adrenal (HPA) axis function assessed with the combined dexamethasone (DEX)/corticotropin releasing hormone (CRH) test has been shown to be associated with response to antidepressant treatment. A polymorphism (rs16944) in the interleukin-1beta (IL-1β) gene has also been reported to be associated with the medication response in depression. These findings prompted us to examine the possible association between IL-1β gene polymorphisms and HPA axis function assessed with the DEX/CRH test.

METHODS

DEX/CRH test was performed in 179 healthy volunteers (45 males: mean age 40.5 ± 15.8 years; 134 females: mean age 47.1 ± 13.2 years). Five tagging single nucleotide polymorphisms (SNPs) of IL-1β gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were selected at an r2 threshold of 0.80 with a minor allele frequency > 0.1. Genotyping was performed by the TaqMan allelic discrimination assay. A two-way factorial analysis of variance (ANOVA) was performed with the DEX/CRH test results as the dependent variable and genotype and gender as independent variables. To account for multiple testing, P values < 0.01 were considered statistically significant for associations between the genotypes and the cortisol levels.

RESULTS

The cortisol levels after DEX administration (DST-Cortisol) showed significant associations with the genotypes of rs16944 (P = 0.00049) and rs1143633 (P = 0.0060), with no significant gender effect or genotype × gender interaction. On the other hand, cortisol levels after CRH administration (DEX/CRH-Cortisol) were affected by gender but were not significantly influenced by the genotype of the examined SNPs, with no significant genotype × gender interaction.

CONCLUSIONS

Our results suggest that genetic variations in the IL-1β gene contribute to the HPA axis alteration assessed by DST-Cortisol in healthy subjects. On the other hand, no significant associations of the IL-1β gene polymorphisms with the DEX/CRH-Cortisol were observed. Confirmation of our findings in futures studies may add new insight into the communication between the immune system and the HPA axis.