Sleep deprivation effects on the activity of the hypothalamic-pituitary-adrenal and growth axes: potential clinical implications

Canadian Network for Mood and Anxiety Treatments (CANMAT) Clinical guidelines for the management of major depressive disorder in adults. V. Complementary and alternative medicine treatments

BACKGROUND

In 2001, the Canadian Psychiatric Association and the Canadian Network for Mood and Anxiety Treatments (CANMAT) partnered to produce evidence-based clinical guidelines for the treatment of depressive disorders. A revision of these guidelines was undertaken by CANMAT in 2008-2009 to reflect advances in the field. There is widespread interest in complementary and alternative medicine (CAM) therapies in the treatment of major depressive disorder (MDD).

METHODS

The CANMAT guidelines are based on a question-answer format to enhance accessibility to clinicians. An evidence-based format was used with updated systematic reviews of the literature and recommendations were graded according to Level of Evidence using pre-defined criteria. Lines of Treatment were identified based on criteria that included evidence and expert clinical support. This section on "Complementary and Alternative Medicine Treatments" is one of 5 guideline articles.

RESULTS

There is Level 1 evidence to support light therapy in seasonal MDD and St. John's wort in mild to moderate MDD. There is also some evidence for the use of exercise, yoga and sleep deprivation, as well as for omega-3 fatty acids and SAM-e . Support for other natural health products and therapies is still limited.

LIMITATIONS

The evidence base remains limited and studies often have methodological problems, including small samples, variability in dose, short duration of treatment, unknown quality of the agent and limited long-term data. Safety data are also sparse with little information about drug interactions.

CONCLUSIONS

Some CAM treatments have evidence of benefit in MDD. However, problems with standardization and safety concerns may limit their applicability in clinical practice.

Stress and obesity: the role of the hypothalamic-pituitary-adrenal axis in metabolic disease

PURPOSE OF REVIEW

Chronic stress, combined with positive energy balance, may be a contributor to the increased risk for obesity, especially upper body obesity, and other metabolic diseases. This association may be mediated by alterations in the hypothalamic-pituitary-adrenal (HPA) axis. In this review, we summarize the major research that has been conducted on the role of the HPA axis in obesity and metabolic disease.

RECENT FINDINGS

Dysregulation in the HPA axis has been associated with upper body obesity, but data are inconsistent, possibly due to methodological differences across studies. In addition to systemic effects, changes in local cortisol metabolism in adipose tissue may also influence the risk for obesity. HPA axis dysregulation may be the causal link between conditions such as maternal malnutrition and sleep deprivation with metabolic disease.

SUMMARY

The present review provides evidence for the relationship between chronic stress, alterations in HPA activity, and obesity. Understanding these associations and its interactions with other factors will be important in developing effective treatments for obesity and related metabolic diseases.

Stress and disorders of the stress system

All organisms must maintain a complex dynamic equilibrium, or homeostasis, which is constantly challenged by internal or external adverse forces termed stressors. Stress occurs when homeostasis is threatened or perceived to be so; homeostasis is re-established by various physiological and behavioral adaptive responses. Neuroendocrine hormones have major roles in the regulation of both basal homeostasis and responses to threats, and are involved in the pathogenesis of diseases characterized by dyshomeostasis or cacostasis. The stress response is mediated by the stress system, partly located in the central nervous system and partly in peripheral organs. The central, greatly interconnected effectors of this system include the hypothalamic hormones arginine vasopressin, corticotropin-releasing hormone and pro-opiomelanocortin-derived peptides, and the locus ceruleus and autonomic norepinephrine centers in the brainstem. Targets of these effectors include the executive and/or cognitive, reward and fear systems, the wake-sleep centers of the brain, the growth, reproductive and thyroid hormone axes, and the gastrointestinal, cardiorespiratory, metabolic, and immune systems. Optimal basal activity and responsiveness of the stress system is essential for a sense of well-being, successful performance of tasks, and appropriate social interactions. By contrast, excessive or inadequate basal activity and responsiveness of this system might impair development, growth and body composition, and lead to a host of behavioral and somatic pathological conditions.

Mid-term effects of serial sleep deprivation therapy implemented in cognitive-behavioral treatment on the neuroendocrine response to clomipramine in patients with major depression

While data dealing with neurobiological effects of sleep deprivation (SD) are mainly restricted to the acute effects of a single night, only few studies have investigated mid-term effects after repeated SD. We therefore examined the clinical and hormonal characteristics of depressive patients before and after serial SD to determine potential sustained effects, focusing especially on serotoninergic functions. One tool to investigate serotoninergic dysfunction in depression is the use of serotoninergic agents to stimulate hormonal secretion, which is assumed to normalize during a clinically effective therapy. Eighteen drug-free inpatients with unipolar major depression received cognitive-behavioral treatment for three weeks and - according to a randomized control design - additional SD therapy (six nights of total SD within three weeks, separated by nights of recovery sleep) or no SD therapy (control group). Serotoninergic function was assessed by measuring cortisol and prolactin in response to intravenously administered clomipramine (12.5mg) before and after the treatment period. The post-treatment challenge test was performed three days after the last SD night. Apart from of a transient overnight improvement of mood induced by SD, both groups showed a comparable clinical course during the three-week treatment period. Compared to the control group, the SD-treated patients exhibited significantly decreased pre-stimulation cortisol levels and significantly increased cortisol responses to clomipramine, whereas no treatment effects were observed for prolactin. In conclusion, our findings suggest that the mid-term effects of serial SD therapy lead to a normalization of serotoninergic dysfunction, although an obvious impact on clinical symptoms was not detected.

Sleeping problems as a risk factor for subsequent musculoskeletal pain and the role of job strain: results from a one-year follow-up of the Malmö Shoulder Neck Study Cohort

BACKGROUND

The role of sleeping problems in the causal pathway between job strain and musculoskeletal pain is not clear.

PURPOSE

To investigate the impact of sleeping problems and job strain on the one-year risk for neck, shoulder, and lumbar pain.

METHOD

A prospective study, using self-administered questionnaires, of a healthy cohort of 4,140 vocationally active persons ages 45-64, residing in the city of Malmo.

RESULTS

At follow-up, 11.8% of the men and 14.8% of the women had developed pain. The odds ratios (OR) for pain at follow-up and sleeping problems at baseline were 1.72 (95% CI: 1.13-2.61) in men and 1.91 (1.35-2.70) in women. Regarding exposure to job strain, ORs were 1.39 (0.94-2.05) for men and 1.63 (1.18-2.23) for women. These statistically significant risks remained so when controlled for possible confounding. A modest synergistic effect was noted in women with concurrent sleeping problems and job strain, but not in men.

CONCLUSION

One in 15-20 of all new cases of chronic pain in the population could be attributed to sleeping problems. No evidence was found for a causal chain with job strain leading to musculoskeletal pain by the pathway of sleeping problems.

Metabolic Syndrome Pathophysiology and Clinical Presentation

Metabolic syndrome is a relatively new definition, designed to help the health care practitioner to easily identify people at risk for the development of cardiovascular disease and diabetes. With the obesity epidemic, we are witnessing an epidemic of multiple-risk patients. Insulin resistance is the perceived pathophysiology of metabolic syndrome and defines its clinical presentation. Hypertension, dyslipedemia, polycystic ovarian syndrome, fatty liver disease, pre-diabetes, sleep and breathing disorder, certain cancers, and cognitive impairment are many of the presentations of the syndrome; patients with any of these conditions are at a high risk of developing cardiovascular disease and diabetes. The metabolic syndrome helps identify people at risk to allow early intervention for prevention. Lifestyle modification is the most important part of the management of people with the syndrome. Lately medications—though none approved by the U.S. Food and Drug Administration (FDA)—have been recommended by major medical societies when lifestyle modification is not enough or when it fails.

Sleep abnormalities in type 2 diabetes may be associated with glycemic control

Sleep disturbances may be associated with impaired glucose metabolism. The aim of this study was to evaluate sleep duration and quality in relation to glycemic control in patients with type 2 diabetes. In a cross-sectional study, sleep duration and quality were assessed in 47 middle-aged patients with type 2 diabetes treated with oral agents and without sleep disturbing complications and 23 healthy control subjects similar by age, sex, body mass index, occupation and schooling. Sleep was recorded by wrist-actigraphy for three consecutive days under free-living conditions. Univariate analysis showed lower sleep maintenance (P = 0.002) and sleep efficiency (P = 0.005), and higher fragmentation index (P < 0.0001), total activity score (P = 0.05) and moving time (P < 0.0001) in patients with type 2 diabetes. After adjusting for age, gender and schooling, fragmentation index and moving time remained significantly higher in the patients with diabetes (P < 0.05, both). HbA1c correlated inversely with sleep efficiency (r = -0.29; P = 0.047) and positively with moving time (r = 0.31; P = 0.031). These findings suggest that type 2 diabetes is associated with sleep disruptions even in the absence of complications or obesity. The relevance of sleep abnormalities to metabolic control and possible strategies to improve sleep quality in type 2 diabetes deserve further investigation.

Influence of partial sleep deprivation on energy balance and insulin sensitivity in healthy women

BACKGROUND

Voluntary sleep restriction is a lifestyle feature of modern societies that may contribute to obesity and diabetes. The aim of the study was to investigate the impact of partial sleep deprivation on the regulation of energy balance and insulin sensitivity.

SUBJECTS AND METHODS

In a controlled intervention, 14 healthy women (age 23-38 years, BMI 20.0-36.6 kg/m(2)) were investigated after 2 nights of >8 h sleep/night (T0), after 4 nights of consecutively increasing sleep curtailment (7 h sleep/night, 6 h sleep/night, 6 h sleep/night and 4 h sleep/night; T1) and after 2 nights of sleep recovery (>8 h sleep/night; T2). Resting and total energy expenditure (REE, TEE), glucose-induced thermogenesis (GIT), physical activity, energy intake, glucose tolerance and endocrine parameters were assessed.

RESULTS

After a decrease in sleep du-ration, energy intake (+20%), body weight (+0.4 kg), leptin/fat mass (+29%), free triiodothyronine (+19%), free thyroxine (+10%) and GIT (+34%) significantly increased (all p < 0.05). Mean REE, physical activity, TEE, oral glucose tolerance, and ghrelin levels remained unchanged at T1. The effect of sleep loss on GIT, fT3 and fT4 levels was inversely related to fat mass.

CONCLUSION

Short-term sleep deprivation increased energy intake and led to a net weight gain in women. The effect of sleep restriction on energy expenditure needs to be specifically addressed in future studies using reference methods for total energy expenditure.

Effects of sleep restriction periods on serum cortisol levels in healthy men

OBJECTIVES

To clarify effects of partial sleep deprivation (SD) on morning (07:00) serum cortisol concentrations in two protocols that restricted sleep to 3h/day in healthy adult men. The study was also designed to delineate the relationship between anxiety levels in the morning and slow wave sleep (SWS) periods at night.

METHODS

Ten young adult Han Chinese males were recruited to participate in an 'earlier-night' sleep restriction (SR) period (sleep from 00:00 to 03:00) and then a 'later-night' SR period (sleep from 03:00 to 06:00). The duration of each SR period was 4 days, followed by a recovery night. The SR periods were separated by 10 days of normal sleep. Blood samples of serum cortisol were drawn at 07:00 during each of two SR periods for six consecutive mornings (for a total of 12 measurements per subject), and anxiety levels were also assessed over the same period by the State portion of the State-Trait Anxiety Inventory (STAI). Sleeping processes were monitored by polysomnogram.

RESULTS

Serum cortisol levels decreased after SR (P<0.05) in both paradigms, with greater decreases evident after later-night sleep loss than after earlier-night sleep loss. Cortisol levels were significantly, negatively correlated to the number of days of earlier-night SR, but not to later-night SR. Anxiety scores increased gradually in both conditions. The time of SWS changed indiscriminately in both paradigms. Cortisol levels returned to baseline after one night of recovery sleep.

CONCLUSIONS

Cortisol decreased in both SR conditions, especially in the earlier-night SR protocol, even though SWS time and anxiety levels changed roughly in the same manner in both conditions. Data suggested that sleep loss at different times of the night affects the hypothalamic-pituitary-adrenal axis (HPA-axis) differentially.

Metabolic complications of obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome is a widely prevalent disorder, hallmarked by partial or total upper airway obstruction during sleep. These events fracture sleep integrity resulting in chronic partial sleep deprivation with destructive metabolic sequelae, the focus of this review.

The effects of 40 hours of total sleep deprivation on inflammatory markers in healthy young adults

Inflammatory cytokines are released in response to stress, tissue damage, and infection. Acutely, this response is adaptive; however, chronic elevation of inflammatory proteins can contribute to health problems including cardiovascular, endocrine, mood, and sleep disorders. Few studies have examined how sleep deprivation acutely affects inflammatory markers, which was the aim of the current study. Nineteen healthy men and women aged 28.05+/-8.56 (mean+/-SD) were totally sleep deprived for 40 h under constant routine conditions. Pro-inflammatory markers: intracellular adhesion molecule-1 (ICAM-1), E-selectin, vascular adhesion molecule-1 (VCAM-1), c-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-1beta (IL-1beta), and the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1ra) were assayed in plasma. Daytime levels during baseline (hours 1-15 of scheduled wakefulness) were compared to daytime levels during sleep deprivation (hours 25-39 of scheduled wakefulness), thus controlling for circadian phase within an individual. Repeated measures ANOVA with planned comparisons showed that 40 h of total sleep deprivation induced a significant increase in E-selectin, ICAM-1, IL-1beta, and IL-1ra, a significant decrease in CRP and IL-6, and no significant change in VCAM-1. Alterations in circulating levels of pro- and anti-inflammatory cytokines and cell adhesion molecules during sleep deprivation were consistent with both increased and decreased inflammation. These findings suggest that one night of sleep loss triggers a stress response that includes stimulation of both pro- and anti-inflammatory proteins in the healthy young subjects tested under our experimental conditions.

Sleep duration is associated with an increased risk for the prevalence of type 2 diabetes in middle-aged women - The FIN-D2D survey

OBJECTIVE

To examine the association between sleep duration with type 2 diabetes and abnormal glucose tolerance among middle-aged men and women in Finland.

METHODS

The FIN-D2D survey is a population-based cross-sectional multicentre study in Finland, with 1336 men and 1434 women aged 45-74 participating in the survey during 2004 and 2005. A health examination including an oral glucose tolerance test and sleep questionnaire was performed for all participants.

RESULTS

There was an independent association between abnormal sleeping times and type 2 diabetes in middle-aged women. Even after adjustments for age, body mass index, sleep apnea probability, smoking, physical activity, and central nervous system-affecting medication, sleep duration of 6h or less or 8h or longer was independently associated with type 2 diabetes. There was no increase in the prevalence of diabetes in middle-aged men with abnormal sleeping times.

CONCLUSION

Short (< or = 6h) or long (> or = 8h) sleep duration is related to an increased risk of type 2 diabetes in middle-aged women but not in men.

Violence, stress, and somatic syndromes

Syndromes characterized by pain, fatigue, mood disorder, cognitive dysfunction, and sleep disturbance have been referred to as stress-related somatic disorders by virtue of the observation that onset and exacerbation of symptoms occur with stress. These syndromes include but are not limited to fibromyalgia, chronic fatigue syndrome, temporomandibular disorder, and irritable bowel syndrome. As with most chronic illnesses, genetic susceptibility and lifetime environmental exposures play a role in creating vulnerability to disease. Cumulative lifetime stress has been associated with a number of physiologic changes in the brain and body that reflect dysregulated hormonal and autonomic activity. Exposure to the stressor of violence is likely to create a state of vulnerability for the stress-related somatic syndromes and also to contribute to symptom expression and severity. Understanding the relationship between violence, stress, and somatic syndromes will help in clarifying the consequences of violence exposure to long-term health and health-related quality of life.

CHRONIC INSOMNIA AND STRESS SYSTEM

SynopsisIn insomnia, which is a very common sleep disorder, objective sleep measures, EEG activity, physiologic findings, HPA axis activity and inflammation markers suggest that it is not a state of sleep loss, but a disorder of hyperarousal present both during the night and the daytime. Several psychological and physiological factors contribute to the onset and perpetuation of insomnia, such as anxious-ruminative personality traits, stressful events, age-related sleep homeostasis weakening mechanisms, menopause and biologic - genetic diathesis of CNS hyperarousal. The therapeutic approach in insomnia should be multidimensional reducing the overall emotional and physiologic hyperarousal and its underlying factors present throughout the 24-h sleep/wake period.

Circadian cortisol profiles and psychological self-reports in shift workers with and without recent change in the shift rotation system

Cortisol profiles including the cortisol rise in the first hour after awakening (CAR) were assessed during shift work and days off (eight saliva samples per shift). Participants were 102 healthy permanent day and night shift workers (comparison groups) and former permanent day and night shift workers after implementation of a new fast-forward rota including morning, evening, and night shifts. Results show that the CAR is detectable in day as well as night shifts. In permanent night workers cortisol profiles appear to be blunted during night work and days off. However, circadian cortisol profiles are not disturbed in former night workers who recently switched to the fast rotating shift schedule. In contrast, implementation of night work in former day workers seems to lead to initially blunted cortisol profiles that normalize after a short adjustment period. Results of a psychological assessment including exhaustion, chronic stress, effort-reward imbalance, and ratings of sleep quality and sleep length are also presented.

Daytime napping after a night of sleep loss decreases sleepiness, improves performance, and causes beneficial changes in cortisol and interleukin-6 secretion

Sleep loss has been associated with increased sleepiness, decreased performance, elevations in inflammatory cytokines, and insulin resistance. Daytime napping has been promoted as a countermeasure to sleep loss. To assess the effects of a 2-h midafternoon nap following a night of sleep loss on postnap sleepiness, performance, cortisol, and IL-6, 41 young healthy individuals (20 men, 21 women) participated in a 7-day sleep deprivation experiment (4 consecutive nights followed by a night of sleep loss and 2 recovery nights). One-half of the subjects were randomly assigned to take a midafternoon nap (1400-1600) the day following the night of total sleep loss. Serial 24-h blood sampling, multiple sleep latency test (MSLT), subjective levels of sleepiness, and psychomotor vigilance task (PVT) were completed on the fourth (predeprivation) and sixth days (postdeprivation). During the nap, subjects had a significant drop in cortisol and IL-6 levels (P < 0.05). After the nap they experienced significantly less sleepiness (MSLT and subjective, P < 0.05) and a smaller improvement on the PVT (P < 0.1). At that time, they had a significant transient increase in their cortisol levels (P < 0.05). In contrast, the levels of IL-6 tended to remain decreased for approximately 8 h (P = 0.1). We conclude that a 2-h midafternoon nap improves alertness, and to a lesser degree performance, and reverses the effects of one night of sleep loss on cortisol and IL-6. The redistribution of cortisol secretion and the prolonged suppression of IL-6 secretion are beneficial, as they improve alertness and performance.

Use of information and communication technology (ICT) and perceived health in adolescence: the role of sleeping habits and waking-time tiredness

The first aim for this paper was to examine gender and age differences in the intensity of usage of information and communication technology (ICT: computer for digital playing, writing and e-mailing and communication, and Internet surfing, and mobile phone). Second, we modelled the possible mediating role of sleeping habits and waking-time tiredness in the association between ICT usage and perceived health (health complaints, musculoskeletal symptoms, health status). The participants were 7292 Finns aged 12, 14, 16 and 18 years responding to a postal enquiry (response rate 70%). The results showed that boys played digital games and used Internet more often than girls, whose mobile phone usage was more intensive. Structural equation model analyses substantiated the mediating hypothesis: intensive ICT-usage was associated with poor perceived health particularly or only when it negatively affected sleeping habits, which in turn was associated with increased waking-time tiredness. The associations were gender-specific especially among older adolescents (16- and 18-year olds). Intensive computer usage forms a risk for boys', and intensive mobile phone usage for girls' perceived health through the mediating links. Girls were vulnerable to the negative consequences of intensive mobile phone usage, as it associated with perceived health complaints and musculoskeletal symptoms both directly and through deteriorated sleep and increased waking-time tiredness. The results of gender-specific ICT usage and vulnerability are discussed as reflecting gendered psychophysiological, psychological and social developmental demands.

Neuroendocrine Regulation of Sleep Disturbances in PTSD

Studies that have conducted quantitative analysis of the sleep electroencephalogram (EEG) have demonstrated decreased delta sleep in PTSD. Elevations in both hypothalamic (neurohormonal) and extrahypothalamic (neurotransmitter) corticotropin releasing factor (CRF) release is associated with decreased delta sleep activity. We present data from several studies examining the effect of metyrapone administration on the sleep EEG in PTSD and control subjects. Plasma ACTH, cortisol, and 11-deoxycorticol were obtained the morning following polysomnographic sleep recordings before and after metyrapone administration. Delta sleep was measured by period amplitude analysis. The results demonstrate: a) decreased delta sleep in male subjects with PTSD; b) metyrapone administration resulted in an activation of the sleep EEG and a robust decrease in quantitative delta sleep; c) the sleep and endocrine (increase in ACTH) responses to metyrapone were significantly decreased in PTSD in two different study samples; and d) the metyrapone-related disruption to sleep in both samples was predicted by the increase in ACTH measured the following morning. These findings strongly suggest that the delta sleep response to metyrapone is a measure of the brain response to a hypothalamic CRF challenge. The attenuated delta sleep and endocrine response to metyrapone challenge in PTSD is consistent with a model of enhanced negative feedback regulation or downregulation of CRF receptors in an environment of chronically increased CRF activity.

Sleep disturbances as predictors of hospitalization for back disorders-a 28-year follow-up of industrial employees

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To study the relationship of sleep disturbances with severe back disorders leading to hospitalization.

SUMMARY OF BACKGROUND DATA

Sleep disturbances are associated with persistent pain syndromes, but little is known about their relationship with back disorders.

METHODS

The first hospital admission for back disorders from 1973 to 2000 was studied in a cohort of metal industry workers (n = 902). The occurrence of sleep disturbances at baseline was categorized as: none; 1 type (either difficulties in falling asleep/waking up at night or nightmares); or both types. Cox proportional hazards regression was used to estimate the time between the assessment of risk factors and first hospital admission for back disorders.

RESULTS

Those individuals who had 1 type of sleep disturbance had a 2.1-fold (95% confidence interval 1.1-3.8) risk of back-related hospitalization, and those with both types of disturbance a 2.4-fold (1.2-4.6) risk, compared with those with no sleep disturbances. The hazard ratios were 2.1; 1.0-4.6 and 2.9; 1.2-7.1, respectively, when patients with chronic back disease or recurrent back symptoms at baseline were excluded from the analyses.

CONCLUSION

These findings suggest that sleep disturbances are predictive of hospitalization for back disorders. The mechanism underlying this association warrants further study.

Sleep disturbances in midlife unrelated to 32-year diabetes incidence: the prospective population study of women in Gothenburg

OBJECTIVE

To study the relation between diabetes incidence and sleep problems in a population-based sample of women followed for 32 years.

RESEARCH DESIGN AND METHODS

The researchers conducted a prospective population study initiated in 1968-1969, with follow-ups in 1974-1975, 1980-1981, 1992-1993, and 2000-2001 in Gothenburg, Sweden. A total of 1,462 women born in 1908, 1914, 1918, 1922, and 1930, representative of women of the same ages in the general population, initially participated (90% participation rate). Reported sleep duration, sleep problems, and use of sleeping medication were related to incident diabetes from 1968 to 2000. Associations between sleep problems and diabetes were corrected for waist-to-hip ratio (WHR), BMI, subscapular skinfold, fasting blood glucose and serum lipid concentrations, blood pressure, heart rate, smoking, physical activity, education, and socioeconomic status. Additionally, associations between BMI, WHR, and sleep problems were examined.

RESULTS

Over 32 years, 126 women (8.7%) developed diabetes. Associations between diabetes and initial sleep problems were tested in a Cox regression analysis, taking into consideration factors associated (P < 0.1) with diabetes. Sleep problems in 1968 did not increase risk of developing diabetes during the following 32 years. Obesity, particularly centralized, was associated with sleep problems.

CONCLUSIONS

No association between sleep problems and developing diabetes was seen in this 32-year follow-up of middle-aged women. Obesity, on the other hand, known to cause increased risk of diabetes, was associated with current sleep problems.

Is peri-operative cortisol secretion related to post-operative cognitive dysfunction?

BACKGROUND

The pattern of cortisol secretion is influenced by surgery. As cortisol can adversely affect neuronal function, this may be an important factor in the development of post-operative cognitive dysfunction (POCD). We hypothesized that the incidence of POCD would be related to changes in cortisol level.

METHODS

We studied 187 patients aged over 60 years undergoing major non-cardiac surgery with general or regional anaesthesia. Saliva cortisol levels were measured pre-operatively and at 1 day, 7 days and 3 months post-operatively in the morning (08.00 h) and in the afternoon (16.00 h) using salivettes. Cognitive function was assessed pre-operatively, on day 7 and at 3 months using four neuropsychological tests. POCD was defined as a combined Z score of greater than 1.96.

RESULTS

After surgery, salivary cortisol concentrations increased significantly. POCD was detected in 18.8% of subjects at 1 week and in 15.2% after 3 months. The pre-operative ratios between the morning and afternoon cortisol concentrations (am/pm ratios) were 2.8 and 2.7 in patients with POCD at 1 week vs. those without POCD at 1 week, respectively. The am/pm ratios decreased significantly post-operatively to 1.9 and 1.6 at 1 week, respectively (P = 0.02 for both). In an analysis considering all am/pm ratios, it was found that the persistent flattening in am/pm ratio was significantly related to POCD at 1 week.

CONCLUSION

The pattern of diurnal variation in cortisol level was significantly related to POCD. Thus, circadian rhythm disturbance or metabolic endocrine stress could be an important mechanism in the development of cognitive dysfunction after major surgery.

Measuring stress and immune response in healthcare professionals following interaction with a therapy dog: a pilot study

This study investigated the optimal time for measuring stress and immune function in 20 healthcare professionals (19 women and 1 man) following interaction with a therapy dog. A nonclinical sample of healthcare professionals was assigned to 20 min. of quiet rest, and 5 and 20 min. with a therapy dog. Serum cortisol, epinephrine, and norepinephrine were collected at baseline, 5, 15, 30, 45, and 60 min. postcondition. Salivary cortisol, salivary IgA, and blood for lymphocytes were collected at baseline, 30, 45, and 60 min. postcondition. Analysis indicated significant reductions in serum and salivary cortisol. The optimal time for measuring serum or salivary cortisol following interaction with a therapy dog was 45 min., with changes in salivary cortisol reflecting serum cortisol changes. Findings also suggest stress reduction in healthcare professionals may occur after as little as 5 min. of interaction with a therapy dog and warrants further investigation.

The ecology of bipolar disorder: the importance of sleep

Although much of the emphasis in treating Bipolar Disorder patients is on pharmacotherapy, sleep loss is an important trigger for mania and plays an important role in the condition. The purpose of this paper is to fully explore the chronobiological, environmental, social, and genetic factors that contribute to the sleep disruption that is characteristic of mania and bipolar disorder. This review is important because sleep, chronobiology, and genetics are under-emphasized content areas in nursing education. As a result, many practicing nurses are unaware of the importance of sleep for mental health or what to teach patients to improve both the quality of their sleep and the management of their condition.

The Effect of Infective Exacerbations on Sleep and Neurobehavioral Function in Cystic Fibrosis

RATIONALE

Adults with cystic fibrosis (CF) are susceptible to hypoxemia, hypercapnia, arousal from sleep, and neurobehavioral impairment.

OBJECTIVES

We hypothesized that pulmonary exacerbations would adversely affect sleep and neurobehavioral performance.

METHODS

Patients with exacerbations (cases) had sleep studies and neurobehavioral testing before and after inpatient intravenous therapy. Adults with stable CF underwent the same testing procedures (control subjects).

MEASUREMENTS AND MAIN RESULTS

When clinically stable, cases and control subjects had similar lung function, intelligence, and body mass index. Among cases, treatment of an exacerbation improved lung function, quality of life, mood, sleepiness, and activation. Cases spent more time awake after sleep onset (p = 0.02), less time in REM sleep (p = 0.03), and were more hypoxemic than control subjects when unwell. The severity of hypoxemia correlated with lung function. On admission, cases had slower throughput than control subjects in the serial addition and subtraction task (cases, 16 +/- 4, vs. control subjects, 17 +/- 3; F[1, 36] = 5.15, p = 0.03) and a slower response time on the digit symbol substitution task (F[1, 36] = 11.91, p = 0.001), which persisted after treatment (F[1, 36] = 8.48, p = 0.006). Cases experienced significant improvements in sleep efficiency, amount of REM sleep, and hypoxia with treatment. Their performance in the serial addition and subtraction task, psychomotor vigilance task, and simulated driving task also improved with treatment. Sex modified the effect of an exacerbation on some aspects of performance.

CONCLUSIONS

Exacerbations of lung disease in adults with CF adversely affect sleep and tests of neurobehavioral performance regardless of underlying disease severity. The implications for performance in daily life need further evaluation because patients often delay admission to hospital to fulfill study or work commitments.

Hypothalamic-pituitary-adrenal axis activity and sleep in posttraumatic stress disorder

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis and sleep disturbances have been described separately in post-traumatic stress disorder (PTSD). It is not known if HPA alterations and sleep disturbances are associated in PTSD. This study examined sleep and HPA activity in 20 male medication-free subjects with PTSD and 16 matched healthy controls. Two nights of polysomnography were obtained and 24-h urinary cortisol was collected during day 2. Subjects self-administered a low-dose (0.5 mg) salivary dexamethasone test at home. Compared with controls, PTSD subjects had higher 24-h urinary microg cortisol/g creatinine (mean+/-SD 40+/-17 vs 28+/-12, p=0.03) but not significantly higher 24-h urinary cortisol (mean+/-SD 52+/-15 microg/day vs 43+/-23, p=0.19). PTSD subjects showed a trend towards less cortisol suppression after dexamethasone (73%+/-18 vs 83%+/-10, p=0.06). In the combined sample, delta sleep was significantly and negatively correlated with 24-h urinary cortisol (r=-0.36, p=0.04), and with 24-h urinary cortisol/g creatinine on a trend level (r=-0.34, p=0.06). Our results suggest that increased cortisol is negatively associated with delta sleep. This may contribute to sleep abnormalities in conditions associated with elevated cortisol, possibly including PTSD. Future studies should explore the temporal relationship between HPA activity, sleep disturbances, and psychopathology after a traumatic event.

IL-6 and its circadian secretion in humans

Interleukin-6 (IL-6) is a pleiotropic cytokine produced by numerous types of immune and nonimmune cells and is involved in many pathophysiologic mechanisms in humans. Many studies suggest that IL-6 is a putative 'sleep factor' and its circadian secretion correlates with sleep/sleepiness. IL-6 is elevated in disorders of excessive daytime sleepiness such as narcolepsy and obstructive sleep apnea. It correlates positively with body mass index and may be a mediator of sleepiness in obesity. Also the secretion of this cytokine is stimulated by total acute or partial short-term sleep loss reflecting the increased sleepiness experienced by sleep-deprived individuals. Studies that evaluated the 24-hour secretory pattern of IL-6 in healthy young adults suggest that IL-6 is secreted in a biphasic circadian pattern with two nadirs at about 08.00 and 21.00, and two zeniths at about 19.00 and 05.00 h. In contrast, following sleep deprivation or in disorders of sleep disturbance, e.g., insomnia, IL-6 peaks during the day and, based on the level of stress system activity, i.e., cortisol secretion, contributes to either sleepiness and deep sleep (low cortisol) or feelings of tiredness and fatigue and poor sleep (high cortisol). In order to address concerns about the potential impact of differences of IL-6 levels between the beginning and the end of the 24-hour blood-drawing experiment, we proceeded with a cosinor analysis of 'detrended' data in young and old healthy individuals. This new analysis did not affect the biphasic circadian pattern of IL-6 secretion in young adults, while it augmented the flattened circadian pattern in old individuals in whom the difference was greater. Finally, IL-6 appears to be somnogenic in rats and exhibits a diurnal rhythm that follows the sleep/wake cycle in these animals. We conclude that IL-6 is a mediator of sleepiness and its circadian pattern reflects the homeostatic drive for sleep.

Microarousals during sleep are associated with increased levels of lipids, cortisol, and blood pressure

OBJECTIVE

Previous work has demonstrated a link between restricted sleep and risk indicators for cardiovascular and metabolic disease, such as levels of cortisol, lipids, and glucose. The present study sought to identify relations between polysomnographic measures of disturbed sleep (frequency of arousals from sleep, total sleep time, and sleep efficiency) and a number of such indicators. A second purpose was to relate the number of arousals to mood, stress, work characteristics, and other possible predictors in daily life.

METHODS

Twenty-four people (10 men, 14 women; mean age 30 years), high vs. low on burnout, were recruited from a Swedish IT company. Polysomnographically recorded sleep was measured at home before a workday. Blood pressure, heart rate, morning blood sample, and saliva samples of cortisol were measured the subsequent working day. They were also recorded for diary ratings of sleep and stress, and a questionnaire with ratings of sleep, stress, work conditions, and mood was completed.

RESULTS

A stepwise regression analysis using sleep parameters as predictors brought out number of arousals as the best predictor of morning cortisol (serum and saliva), heart rate, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein (HDL)-, low-density lipoprotein (LDL)-cholesterol, and LDL/HDL-ratio. Work stress/unclear boundaries between work and leisure time was the best predictor of arousals among the stress variables.

CONCLUSION

Consistent with sleep restriction experiments, sleep fragmentation was associated with elevated levels of metabolic and cardiovascular risk indicators of stress-related disorders. Number of arousals also seems to be related to workload/stress.

Heart rate activation during spontaneous arousals from sleep: effect of sleep deprivation

OBJECTIVE

Arousal (AR) from sleep is associated with an autonomic reflex activation raising blood pressure and heart rate (HR). Recent studies indicate that sleep deprivation may affect the autonomic system, contributing to high vascular risk. Since in sleep disorders a sleep fragmentation and a partial sleep deprivation occurs, it could be suggested that the cardiovascular effects observed at AR from sleep might be physiologically affected when associated with sleep deprivation. The aim of the study was to examine the effect of sleep deprivation on cardiac arousal response in healthy subjects.

METHODS

Seven healthy male subjects participated in a 64 h sleep deprivation protocol. Arousals were classified into four groups, i.e. >3<6 s, >6<10 s, >10<15 s and >15 s, according to their duration. Pre-AR HR values were measured during 10 beats preceding the AR onset, and the event-related HR fluctuations were calculated during the 20 beats following AR onset. As an index of cardiac activation, the ratio of highest HR in the post-AR period over the lowest recorded before AR (HR ratio) was calculated.

RESULTS

For AR lasting less than 10 s, the occurrence of AR induces typical HR oscillations in a bimodal pattern, tachycardia followed by bradycardia. For AR lasting more than 10 s, i.e. awakenings, the pattern was unimodal with a more marked and sustained HR rise. The HR response was consistently similar across nights, during NREM and REM sleep, without difference between conditions.

CONCLUSIONS

Overall, total sleep deprivation appeared to have no substantial effect on cardiac response to spontaneous arousals and awakenings from sleep in healthy subjects. Further studies are needed to clarify the role of chronic sleep deprivation on cardiovascular risk in patients with sleep disorders.

SIGNIFICANCE

In healthy subjects acute prolonged sleep deprivation does not affect the cardiac response to arousal.

Sleep restriction does not affect orthostatic tolerance in the simulated microgravity environment

Orthostatic intolerance (OI) is a major problem following spaceflight, and, during flight, astronauts also experience sleep restriction. We hypothesized that sleep restriction will compound the risk and severity of OI following simulated microgravity and exaggerate the renal, cardioendocrine, and cardiovascular adaptive responses to it. Nineteen healthy men were equilibrated on a constant diet, after which they underwent a tilt-stand test. They then completed 14–16 days of simulated microgravity [head-down tilt bed rest (HDTB)], followed by repeat tilt-stand test. During HDTB, 11 subjects were assigned to an 8-h sleep protocol (non-sleep restricted), and 8 were assigned to a sleep-restricted protocol with 6 h of sleep per night. During various phases, the following were performed: 24-h urine collections, hormonal measurements, and cardiovascular system identification. Development of presyncope or syncope defined OI. There was a significant decrease in time free of OI ( P = 0.02) and an increase in OI occurrence ( P = 0.06) after HDTB among all subjects. However, the increase in OI occurrence did not differ significantly between the two groups ( P = 0.60). The two groups also experienced similar physiological changes with HDTB (initial increase in sodium excretion; increased excretion of potassium at the end of HDTB; increase in plasma renin activity secretion without a change in serum or urine aldosterone). No significant change in autonomic function or catecholamines was noted. Simulated microgravity leads to increased OI, and sleep restriction does not additively worsen OI in simulated microgravity. Furthermore, conditions of sleep restriction and nonsleep restriction are similar with respect to renal, cardioendocrine, and cardiovascular responses to simulated microgravity.

Weekend holidays during methylphenidate use in ADHD children: a randomized clinical trial

OBJECTIVE

The aim of this study was to assess whether weekend drug holidays during methylphenidate (MPH) administration would change the efficacy and tolerability to the medication in male children with Attention-Deficit Hyperactivity Disorder (ADHD).

METHODS

In a 28-day, double-blind study, children with diagnoses of ADHD were randomized to receive BID MPH for 7 days a week (n = 21) or to receive BID MPH on weekdays and a placebo on weekends (n = 19). Parents completed the Conners' Abbreviated Rating Scale (ABRS) to assess ADHD symptoms and the Barkley's Side Effect Rating Scale (SERS) to assess side effects on weekends. Teachers completed the ABRS on each Monday after weekends.

RESULTS

Both groups showed a significant reduction on the ABRS over time as the dose was increased. However, the group difference in the ABRS scores was not statistically significant, either on weekend parent ratings (at the endpoint, p = 0.41; effect size = 0.26) or on teachers' ratings (at the endpoint, p = 0.99; effect size = 0.002). The omission of MPH on weekends was associated with significantly less severity of insomnia (F = 3.96, d.f. = 1, p = 0.05) and a trend for less interference on appetite (F = 3.18, d. f. = 1, p = 0.08).

CONCLUSION

Our findings suggest that weekend holidays during MPH administration reduce the side effects of insomnia and appetite suppression without a significant increase in symptoms, either on weekends or in the first school day after them. Possible explanations for these findings (rate-dependent response or impact of demands of the environment) are discussed in this paper.

Incidence of diabetes in middle-aged men is related to sleep disturbances

OBJECTIVE

Sleep deprivation in healthy men has been experimentally found to result in disturbances in glucose metabolism and in sympathovagal imbalance. The aim of the present study was to investigate whether sleep disturbances and elevated resting heart rate are associated with increased risk of developing diabetes.

RESEARCH DESIGN AND METHODS

A group of 6,599 initially healthy, nondiabetic men aged 44.5 +/- 4.0 years took part in a prospective, population-based study in Malmö, Sweden. The incidence of diabetes during a mean follow-up of 14.8 +/- 2.4 years was examined in relation to self-reported difficulties in falling asleep and resting heart rate at baseline. Diabetes was assessed at follow-up in all subjects by questionnaire and in a subgroup of 1,551 men by blood glucose measurement.

RESULTS

A total of 615 (9.3%) subjects reported either difficulties in falling asleep or regular use of hypnotics (seen as markers of sleep disturbances), and 158 (2.4%) subjects reported both of these. Altogether, 281 (4.3%) of the men developed diabetes during the follow-up period. Logistic regression models showed difficulties in falling asleep or regular use of hypnotics (odds ratio [OR] 1.52 [95% CI 1.05-2.20]) and resting heart rate (OR per 10 bpm 1.13 [0.99-1.30]) to be associated with development of diabetes when full adjustments were made for baseline age, biological risk factors, lifestyle, family history of diabetes, and social class.

CONCLUSIONS

The results suggest that sleep disturbances and, possibly, elevated resting heart rate, in middle-aged men, are associated with an increased risk of diabetes.

Prolonged psychological stress suppresses cortisol secretion

OBJECTIVE

Response to acute psychological stress is characterized by activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. However, response to the prolonged psychological stress is less well known.

DESIGN

This study was designed as a prospective assessment of cortisol secretion during prolonged psychological stress induced by continuous air raids and after elimination of the stress-inducing factor.

SUBJECTS

The study group consisted of five healthy subjects (34-39 years).

MEASUREMENTS

Psychological and endocrine (morning cortisol and 1 microg ACTH test) testing was done 2 months after the war had begun and 18 months after the end of it. Psychiatric assessment was done at the same periods, and 30 months after the start of the study.

RESULTS

After 2.5 years of follow-up, there were no signs of endocrine or psychiatric disorders in any of the subjects. After the war, Beck Inventory of Depression and Hamilton Anxiety Rating Scale scores were significantly reduced. Suppression of the HPA axis was present during the war but not after.

CONCLUSIONS

Prolonged psychological stress is associated with a transient suppression of the HPA axis, manifested by low morning cortisol and reduced cortisol response to ACTH. The reduction of cortisol response is sufficient to cause false diagnosis of HPA insufficiency.

Delta sleep response to metyrapone in post-traumatic stress disorder

Metyrapone blocks cortisol synthesis, which results in the stimulation of hypothalamic cortiocotropin-releasing factor (CRF) and a reduction in delta sleep. We examined the effect of metyrapone administration on endocrine and sleep measures in male subjects with and without chronic PTSD. We hypothesized that metyrapone would result in a decrease in delta sleep and that the magnitude of this decrease would be correlated with the endocrine response. Finally, we utilized the delta sleep response to metyrapone as an indirect measure of hypothalamic CRF activity and hypothesized that PTSD subjects would have decreased delta sleep at baseline and a greater decrease in delta sleep induced by metyrapone. Three nights of polysomnography were obtained in 24 male subjects with combat-related PTSD and 18 male combat-exposed normal controls. On day 3, metyrapone was administered during normal waking hours until habitual sleep onset preceding night 3. Endocrine responses to metyrapone were measured in plasma obtained the morning following sleep recordings, the day before and after administration. Repeated measures ANOVAs were conducted to compare the endocrine and sleep response to metyrapone in PTSD and controls. PTSD subjects had significantly less delta sleep as indexed by stages 3 and 4, and total delta integrated amplitude prior to metyrapone administration. There were no differences in premetyrapone cortisol or ACTH levels in PTSD vs controls. PTSD subjects had a significantly decreased ACTH response to metyrapone compared to controls. Metyrapone caused an increase in awakenings and a marked decrease in quantitative measures of delta sleep that was significantly greater in controls compared to PTSD. The decline in delta sleep was significantly associated with the magnitude of increase in both 11-deoxycortisol and ACTH. The results suggest that the delta sleep response to metyrapone is a measure of the brain response to increases in hypothalamic CRF. These data also suggest that the ACTH and sleep EEG response to hypothalamic CRF is decreased in PTSD.

Effects of sleep loss in men and women with insufficient sleep suffering from chronic disease: a model for supportive nursing care

This study evaluated self-reported subjective health and effects of sleep loss according to perceived interfering cognitive anxiety related to falling asleep in patients with and without insufficient sleep and gender differences in these aspects 5 years after coronary artery bypass graft and transluminal coronary angioplasty. A total of 145 patients, five years after intervention, responded to a mailed questionnaire. Nearly 60% had severe combined sleep disturbances; 35.9% of these had complained of insufficient sleep and 15% also perceived difficulty falling asleep related to cognitive anxiety. Measurable gender differences were small. A theoretical framework is presented which can increase understanding among nurses, patients and their relatives concerning the quality and quantity of sleep and sleep loss related to quality of life. These results suggest that there are significant relationships between sleep quality, resilience to stress and coping strategy in patients with a chronic disease, indicating the need for more individualised supportive nursing care.

Pentagastrin-induced sleep panic attacks: panic in the absence of elevated baseline arousal

BACKGROUND

It has been suggested that pharmacological challenges that induce panic attacks are confounded by effects of environmental stress, elevated baseline arousal, and expectancy bias.

METHODS

To control for effects of arousal and cognition on the panicogenic effects of pentagastrin, pharmacological challenges were conducted during sleep in seven patients with panic disorder or social phobia. All patients had previously experienced pentagastrin-induced panic while awake. Infusions of normal saline and pentagastrin (0.6 microg/kg) were administered in fixed order and timed so that pentagastrin infusions took place during the transition from Stage 2 to Stage 3 sleep. Long intravenous lines were placed for remote blood sampling and subsequent analysis of plasma adrenocorticotropic hormone and cortisol. Measures of anxiety and panic were obtained at baseline and upon awakening after pharmacological challenge.

RESULTS

All seven subjects awoke within seconds following pentagastrin infusion. Four patients reported symptoms that met criteria for panic. Neither baseline anxiety nor neuroendocrine measures were predictive of panic.

CONCLUSIONS

These data demonstrate the ability to induce panic during a period of diminishing arousal and indicate that panic attacks can occur in the absence of elevated arousal and environmental stress.

Sleep duration, insomnia and behavioral problems among Chinese adolescents

This study examined the associations among sleep duration, insomnia, and behavioral problems in a sample of 1359 Chinese adolescents. Participants completed a self-administrated questionnaire that included questions on sleep duration and insomnia symptoms and the Youth Self-Report of Child Behavior Checklist. It was found that adolescents who complained of insomnia reported sleep duration only half an hour shorter than did those without insomnia. Sleep duration did not differ among adolescents reporting three different types of insomnia (difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening). Adolescents with insomnia reported more behavioral problems than did those without complaints of insomnia. After adjustment for age and sex, sleep duration of less than 7 h a day was significantly associated with most behavioral problems in those without complaints of insomnia but with only a few behavioral problems in adolescents reporting insomnia. Results suggest that sleep duration in adolescents with insomnia is short, but not as short as reported in previous clinical studies. Insomnia and short sleep duration are associated with a wide range of behavioral and emotional problems in adolescents.

Hormonal and behavioural responses of paradoxical sleep-deprived rats to the elevated plus maze

Activation of the hypothalamic-pituitary-adrenal (HPA) axis is observed immediately after 96 h of paradoxical sleep (PS) deprivation. However, when individually or group PS-deprived rats are challenged with a mild stressor, they exhibit a facilitation of the corticosterone response, and a faster return to basal levels than control rats. Because the housing condition influences coping behaviour, we tested whether the type of PS deprivation (individually or in group) influenced anxiety-like behaviour in the elevated plus-maze and the accompanying adrenocorticotropin (ACTH) and corticosterone responses. Individually (I-DEP) or group deprived (G-DEP) rats and their appropriate control groups were either killed immediately after 96 h of sleep deprivation (time-point 0 or 'basal') or exposed to a 5-min test on the elevated plus maze and sampled 5, 20 or 60 min after test onset. Control of I-DEP rats showed reduced locomotor activity and augmented anxiety-like behaviour, replicating the effects of social isolation. Although I-DEP rats exhibited higher motor activity than cage control rats, these groups did not differ in regard to the percentage of entry and time spent in the open arms. G-DEP rats, in turn, ambulated more, entered and remained longer in the open arms, exhibiting less anxiety-like behaviour. PS-deprived rats exhibited higher ACTH and corticosterone 'basal' secretion than control rats. For all groups, peak ACTH secretion was reached at the 5-min time-point, returning to unstressed basal levels 60 min after the test, except for G-DEP rats, which showed a return at 20 min. Peak levels of corticosterone occurred at 5 min for PS-deprived groups and at 20 min for control groups. G-DEP rats showed a return to 'basal' unstressed levels at 20 min, whereas the I-DEP and control groups did so at 60 min. A negative correlation between exploration in the open arms and hormone concentrations was observed. These data indicate that housing condition influences the subsequent behaviour of PS-deprived rats in the EPM which, in turn, seems to determine the secretion profile of ACTH and corticosterone in response to the test.

Effects of sleep pressure on endogenous cardiac autonomic activity and body temperature

This study investigated the effects of variations in sleep pressure on cardiac autonomic activity and body temperature. In a counterbalanced design, 12 healthy, young subjects (6 men and 6 women) remained recumbent during 30 h of wakefulness (high sleep pressure) and 6 h of wakefulness (low sleep pressure). Both periods of wakefulness were immediately followed by a sleep opportunity, and the first 2 h of sleep were analyzed. During extended hours of wakefulness, a reduction in heart rate was mediated by a decline in cardiac sympathetic activity (measured via preejection period) and the maintenance of cardiac parasympathetic activity (measured via respiratory sinus arrhythmia). In subsequent high-pressure sleep, parasympathetic activity was amplified and sympathetic activity was negatively associated with electroencephalographic slow-wave activity. Sleep deprivation had no impact on foot temperature, but it did alter the pattern of change in core body temperature. A downregulation of cardiac autonomic activity during both extended hours of wakefulness and subsequent sleep may respectively provide "protection" and "recovery" from the temporal extension of cardiac demand.

Chronic insomnia is associated with nyctohemeral activation of the hypothalamic-pituitary-adrenal axis: clinical implications

Although insomnia is, by far, the most commonly encountered sleep disorder in medical practice, our knowledge in regard to its neurobiology and medical significance is limited. Activation of the hypothalamic-pituitary-adrenal axis leads to arousal and sleeplessness in animals and humans; however, there is a paucity of data regarding the activity of the hypothalamic-pituitary-adrenal axis in insomniacs. We hypothesized that chronic insomnia is associated with increased plasma levels of ACTH and cortisol. Eleven young insomniacs (6 men and 5 women) and 13 healthy controls (9 men and 4 women) without sleep disturbances, matched for age and body mass index, were monitored in the sleep laboratory for 4 consecutive nights, whereas serial 24-h plasma measures of ACTH and cortisol were obtained during the fourth day. Insomniacs, compared with controls, slept poorly (significantly higher sleep latency and wake during baseline nights). The 24-h ACTH and cortisol secretions were significantly higher in insomniacs, compared with normal controls (4.2 +/- 0.3 vs. 3.3 +/- 0.3 pM, P = 0.04; and 218.0 +/- 11.0 vs. 190.4 +/- 8.3 nM, P = 0.07). Within the 24-h period, the greatest elevations were observed in the evening and first half of the night. Also, insomniacs with a high degree of objective sleep disturbance (% sleep time < 70), compared with those with a low degree of sleep disturbance, secreted a higher amount of cortisol. Pulsatile analysis revealed a significantly higher number of peaks per 24 h in insomniacs than in controls (P < 0.05), whereas cosinor analysis showed no differences in the temporal pattern of ACTH or cortisol secretion between insomniacs and controls. We conclude that insomnia is associated with an overall increase of ACTH and cortisol secretion, which, however, retains a normal circadian pattern. These findings are consistent with a disorder of central nervous system hyperarousal rather than one of sleep loss, which is usually associated with no change or decrease in cortisol secretion or a circadian disturbance. Chronic activation of the hypothalamic-pituitary-adrenal axis in insomnia suggests that insomniacs are at risk not only for mental disorders, i.e. chronic anxiety and depression, but also for significant medical morbidity associated with such activation. The therapeutic goal in insomnia should be to decrease the overall level of physiologic and emotional arousal, and not just to improve the nighttime sleep.

Sleep deprivation and hypothalamic-pituitary-adrenal (HPA) axis activity in depressed patients

In the present study we investigated HPA axis activity in depressed patients treated with partial sleep deprivation (PSD) in order to identify endocrinological characteristics related to PSD responsiveness. Thirty-three drug-free patients (14 men, 19 women) suffering from major depression according to DSM-IV criteria were treated with PSD. Response to PSD was defined as a reduction of at least 30% according to the 6-item version of the Hamilton Depression Scale (6-HAMD). Subsequently, the combined dexamethasone-suppression/CRH-stimulation test (DEX/CRH test) was performed. Patients were pretreated with 1.5 mg dexamethasone (DEX) at 23:00 h and challenged with 100 microg corticotropin-releasing hormone (CRH) the following day. Postdexamethasone cortisol concentrations (before CRH administration) served as parameters for the DST status (dexamethasone suppression test). The cortisol stimulation after CRH was used as measurement for the DEX/CRH test status. Of the depressive patients, 54.5% (18 out of 33) responded to PSD. DST suppressors (postdexamethasone cortisol levels < 15 ng/ml) showed a significantly greater reduction in 6-HAMD scores after PSD than DST nonsuppressors. Furthermore, a significant negative correlation between postdexamethasone cortisol levels and reduction in 6-HAMD scores after PSD could be established. However, there was no relationship between the cortisol stimulation following CRH challenge and response to PSD. Although the combined DEX/CRH challenge test is a more sensitive marker for HPA axis dysregulation in depression than the standard DST, the negative feedback of the HPA system reflected by the DST status is apparently more closely associated with response to partial sleep deprivation in major depressive disorder.

Glucocorticoid replacement is permissive for rapid eye movement sleep and sleep consolidation in patients with adrenal insufficiency

There is a well described temporal relation between hormonal secretion and sleep phase, with hormones of the hypothalamic-pituitary-adrenal (HPA) axis possibly playing a role in determining entry into and duration of different sleep stages. In this study sleep features were studied in primary Addison's patients with undetectable levels of cortisol treated in a double blind, randomized, cross-over fashion with either hydrocortisone or placebo supplementation. We found that REM latency was significantly decreased in Addison's patients when receiving hydrocortisone at bedtime, whereas REM sleep time was increased. There was a trend toward an increase in the percentage of time in REM sleep and the number of REM sleep episodes. Waking time after sleep onset was increased, whereas no differences were observed between the two conditions when total sleep time or specific non-REM sleep parameters were evaluated. Our results suggest that in Addison's patients, cortisol plays a positive, permissive role in REM sleep regulation and may help to consolidate sleep. These effects may be mediated either directly by the central effects of glucocorticoids and/or indirectly through CRH and/or ACTH.