Chronic insomnia and immune functioning

[Immune outcomes of sleep disorders: the hypothalamic-pituitary-adrenal axis as a modulatory factor]

OBJECTIVE

To review the literature on the interaction between sleep and the immune system.

METHOD

A search on Web of Science and Pubmed database including the keywords sleep, sleep deprivation, stress, hypothalamic-pituitary-adrenal axis, immune system, and autoimmune diseases.

RESULTS

On Web of Science, 588 publications were retrieved; 61 references, more significant and closer to our objective, were used, including original articles and review papers.

CONCLUSION

Sleep deprivation and immune system exert a bidirectional influence on each other. Since sleep deprivation is considered a stressor, inasmuch as it induces elevation of cortisol or corticosterone levels in humans and rodents, respectively, and given the well-known immunosuppressive effect of glucocorticoids, we propose that increased activation of the hypothalamic-pituitary-adrenal axis is a major mediator of the immune alterations observed in patients with insomnia or in sleep deprived subjects.

Objective and subjective measures for sleep disorders

Subjective and objective measures of sleep structure or quality could help to characterize the chronic sleep disturbances, with relation to patients' risk factor profiles and co-morbidities. Studies have shown that discrepancies can occur between subjective data regarding sleep disturbances and the impact of insomnia and objective assays, and surrogate markers of sleep and sleep disturbances. Both objective and subjective measures should be incorporated into clinic studies. It seems likely that sleep quality is represented by a combination of more than one subjective sleep parameter. Objective and subjective assessments of sleep quality may relate to different parameters. Future studies incorporated both subjective and objective measures could help to address the sleep disorders.

Current methodological approaches to the study of sleep disturbances and quality of life in adults with cancer: a systematic review

In recent years, sleep disturbances and the health-related quality of life (QOL) experienced by adults with cancer, during and after cancer treatment, have received increasing attention in the scientific literature. The purpose of this paper was to systematically review current methodological approaches to the study of sleep disturbances and QOL in adults with cancer. Databases were searched to identify longitudinal studies of adults with cancer that measured sleep disturbances and QOL in the past 10 years. The review was focused in five primary areas: trends in publication, measurement of sleep and QOL, study design, changes in sleep disturbances and QOL, and the level of this evidence. Of the 40 studies that met the authors' criteria for inclusion, 75% were descriptive in design and 25% were intervention studies. Studies on sleep and QOL among cancer patients have become more common since 2000, include a range of sample sizes and settings, use a variety of measures of sleep and QOL, and examine patients undergoing many types of cancer therapies. No programs of research have been developed in sleep disturbances and QOL in adults with cancer. The 'evidence' that can be drawn from such studies is obviously weak. Current approaches usually describe changes over time, but have not described whether a relationship exists between sleep disturbances and QOL in adults with cancer. Directions for future research are suggested.

Long-term nightly treatment with indiplon in adults with primary insomnia: results of a double-blind, placebo-controlled, 3-month study

OBJECTIVES

To evaluate the efficacy and safety of indiplon in primary insomnia.

DESIGN

Randomized, double-blind, placebo-controlled, 3-month study.

SETTING

Multi-center outpatient setting.

PATIENTS

N=702 (61% female; mean age 46 years) who met DSM-IV criteria for primary insomnia of at least 3 months' duration.

INTERVENTIONS

Indiplon 10 mg (n=236), indiplon 20 mg (n=233), or placebo (n=233).

MEASUREMENTS

Subjective assessment of each of the following: latency to sleep onset (sLSO), total sleep time (sTST), number of awakenings after sleep onset (sNAASO), wake time after sleep onset (sWASO), sleep quality, Insomnia Severity Index (ISI), and global improvement.

RESULTS

Treatment with indiplon resulted in significant improvement relative to placebo at all time points for the primary endpoint, sLSO. Mean sLSO at Month 1 for each treatment group was: 10 mg (34.0 +/- 1.3 mins), 20 mg (33.0 +/- 1.3 mins), and placebo (48.7 +/- 1.9 mins; P <0.0001 for both comparisons); efficacy was sustained through Month 3. Both doses of indiplon resulted in significant improvement in sleep maintenance and duration endpoints, sTST and sWASO, as well as sleep quality, ISI, and global improvement at all assessment time points.

CONCLUSIONS

In patients with chronic insomnia, long-term nightly treatment with 10 mg and 20 mg doses of indiplon resulted in significant and sustained efficacy in sleep onset, maintenance, and duration, and significant associated improvement in both daytime functioning and quality of life.

Possible links between behavioral and physiological indices of tiredness, fatigue, and exhaustion in advanced cancer

GOALS

In this theoretical paper, we present the Edmonton Fatigue Framework (EFF), a new framework for the study of tiredness, fatigue, and exhaustion in advanced cancer.

MATERIALS AND METHODS

The Fatigue Adaptation Model (FAM), the starting point for the EFF, was drawn from a literature review pertaining to fatigue in depression, chronic fatigue syndrome, cancer, shift workers, and athletes published in the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed, PsychINFO, SPORTdiscus, and CancerLit between 1995 and 2004, and from seven qualitative studies conducted by our group. The EFF, an elaboration of the FAM, was constructed after an expansion of our literature review to 2006 and team discussion. The EFF provides new insights into possible links between behavioral and physiological indices of tiredness, fatigue, and exhaustion as they occur in both ill and non-ill states. In this paper, however, we consider only possible links in advanced cancer.

CONCLUSIONS

We propose that stressors associated with advanced cancer and its supportive treatment trigger declines in four systems -- cognitive function, sleep quality, nutrition, and muscle endurance -- and that these declines reduce one's ability to adapt. While these systems each likely has its own effect on adaptation, we propose that the most important and serious effects arise from interactions among declines in cognitive function, sleep quality, nutrition, and muscle endurance.

CONCLUSIONS

Interventions for fatigue have been limited by a lack of understanding about its etiology. Hypotheses arising from the EFF; suggest a new direction for further study that focuses on interactions among cognitive function, sleep quality, nutrition, and muscle endurance.

Randomized clinical trial on cognitive therapy for depression in women with metastatic breast cancer: Psychological and immunological effects

Objective:Depression is particularly prevalent in patients with advanced cancer. Cognitive therapy (CT) is an empirically supported treatment for depression in the general population. However, efficacy remains to be demonstrated in patients with advanced cancer. A prior controlled trial of CT in a group format showed improvements in depression, mood disturbance, and self-esteem; however, these effects were not maintained over time. Studies examining the efficacy of individual format CT interventions that may ensure more long-term maintenance of benefits are necessary. This study assessed the efficacy of CT for depression administered individually in women with metastatic breast cancer and its effect on immune function.

Method: Forty-five women were randomly assigned to either individual CT or to a waiting-list control (WLC) condition. CT was composed of eight weekly sessions of CT and three booster sessions administered at 3-week intervals following the end of treatment.

Results: Patients treated with CT had significantly lower scores on the Hamilton Depression Rating Scale at posttreatment compared to untreated patients. Pooled data from both groups indicated significant reductions of depressive symptoms from pre- to posttreatment, as well as reduction of associated symptoms including anxiety, fatigue, and insomnia symptoms. These effects were well sustained at the 3- and 6-month follow-up evaluations. CT for depression did not appear to have a significant impact on immune functioning.

Significance of results: Findings of this study support the efficacy of CT for depression in this population and suggest that the administration of individual and booster sessions after treatment termination may be instrumental in sustaining the treatment effects over time.

The long-term effect of insomnia on work disability: the HUNT-2 historical cohort study

Chronic insomnia is common in the general population. Its effect on functioning and disability is usually attributed to an underlying condition, so the diagnosis of insomnia does not qualify for award of a disability pension in the United States or Europe. The aim of this study was to investigate whether insomnia, defined according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, contributed to long-term work disability. Using a historical cohort design, the authors gathered baseline data from a population-based Norwegian health study of 37,308 working-age people not claiming a disability pension through 1995-1997. The outcome was subsequent award of a disability pension (18-48 months after the health screening) as registered by the National Insurance Administration. Insomnia was a strong predictor of subsequent permanent work disability (adjusted odds ratio=3.90, 95% confidence interval: 3.20, 4.76). Sociodemographic and shift-work characteristics had little confounding effect (adjusted odds ratio=3.69, 95% confidence interval: 3.00, 4.53), and this association remained significant after adjustment for psychiatric and physical morbidity and for health-related behaviors (adjusted odds ratio=1.75, 95% confidence interval: 1.40, 2.20). This study suggests that insomnia should receive increased attention as a robust predictor of subsequent work disability.

Increased nocturnal interleukin-6 excretion in patients with primary insomnia: a pilot study

The aim of the present study was to investigate whether there is a difference in evening/nocturnal interleukin-6 (IL-6) serum excretion in patients with primary insomnia compared to controls. We hypothesized that in insomniac patients, the excretion of evening/nocturnal IL-6 is enhanced, like observed in aged adults and after sleep deprivation in healthy subjects. We studied IL-6 serum concentrations in 11 patients (two males and nine females) with primary insomnia and 11 age and gender-matched healthy controls. Sleep was monitored polysomnographically for three consecutive nights. The measurement of IL-6 (from 19:00 h to 09:00 h) in 2-h intervals were performed prior to and during the last laboratory night. Polysomnographically determined sleep parameters and subjective ratings of sleep demonstrated clear-cut impairments of sleep in the insomniac group. Nocturnal IL-6 secretion was significantly increased (p<.05) in insomniac patients for the whole measurement period (mean area under the curve+/-SD: 27.94+/-14.15 pg/ml x 2h) compared to controls (16.70+/-7.64 pg/ml x 2h). Total IL-6 secretion correlated inversely with subjectively perceived sleep quality and amount of slow wave sleep in the insomniac patients. Amount of Wake Time correlated positively with IL-6 excretion in insomniacs. The results of the present study demonstrate significantly increased nocturnal IL-6 secretion in insomniacs. It might be speculated that chronic primary insomnia with polysomnographically documented sleep impairments activates the production of IL-6 analogous to sleep deprivation studies in healthy subjects. This might also implicate a higher risk for inflammatory and cardiovascular diseases in patients with chronic insomnia.

Sleep wake disturbances in people with cancer and their caregivers: state of the science

PURPOSE/OBJECTIVES

To review the state of the science on sleep/wake disturbances in people with cancer and their caregivers.

DATA SOURCES

Published articles, books and book chapters, conference proceedings, and MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and the Cochrane Library computerized databases.

DATA SYNTHESIS

Scientists have initiated studies on the prevalence of sleep/wake disturbances and the etiology of sleep disturbances specific to cancer. Measurement has been limited by lack of clear definitions of sleep/wake variables, use of a variety of instruments, and inconsistent reporting of sleep parameters. Findings related to use of nonpharmacologic interventions were limited to 20 studies, and the quality of the evidence remains poor. Few pharmacologic approaches have been studied, and evidence for use of herbal and complementary supplements is almost nonexistent.

CONCLUSIONS

Current knowledge indicates that sleep/wake disturbances are prevalent in cancer populations. Few instruments have been validated in this population. Nonpharmacologic interventions show positive outcomes, but design issues and small samples limit generalizability. Little is known regarding use of pharmacologic and herbal and complementary supplements and potential adverse outcomes or interactions with cancer therapies.

IMPLICATIONS FOR NURSING

All patients and caregivers need initial and ongoing screening for sleep/wake disturbances. When disturbed sleep/wakefulness is evident, further assessment and treatment are warranted. Nursing educational programs should include content regarding healthy and disrupted sleep/wake patterns. Research on sleep/wake disturbances in people with cancer should have high priority.

Randomized study on the efficacy of cognitive-behavioral therapy for insomnia secondary to breast cancer, part II: Immunologic effects

PURPOSE

Cross-sectional studies suggest that clinical insomnia is associated with immune downregulation. However, there is a definite need for experimental studies on this question. The goal of this randomized controlled study was to assess the effect of an 8-week cognitive-behavioral therapy (CBT) for chronic insomnia on immune functioning of breast cancer survivors. Previous analyses of this study showed that CBT was associated with improved sleep and quality of life, and reduced psychological distress.

PATIENTS AND METHODS

Fifty-seven women with chronic insomnia secondary to breast cancer were randomly assigned to CBT (n = 27) or to a waiting-list control condition (WLC; n = 30). Peripheral-blood samples were taken at baseline and post-treatment (and postwaiting for WLC patients), as well as at 3-, 6-, and 12-month follow-up for immune measures, including enumeration of blood cell counts (ie, WBCs, monocytes, lymphocytes, CD3+, CD4+, CD8+, and CD16+/CD56+) and cytokine production (ie, interleukin-1-beta [IL-1beta] and interferon gamma [IFN-gamma]).

RESULTS

Patients treated with CBT had higher secretion of IFN-gamma and lower increase of lymphocytes at post-treatment compared with control patients. Pooled data from both treated groups indicated significantly increased levels of IFN-gamma and IL-1beta from pre- to post-treatment. In addition, significant changes in WBCs, lymphocytes, and IFN-gamma were found at follow-up compared with post-treatment.

CONCLUSION

This study provides some support to the hypothesis of a causal relationship between clinical insomnia and immune functioning. Future studies are needed to investigate the clinical impact of such immune alterations.

Using Stress Models to Evaluate Immuno-Modulating Effects of Nutritional Intervention in Healthy Individuals

There is clear evidence that nutritional supplementation helps to restore immune function and contributes to optimal resistance to infections in malnourished people. However, the literature is less clear on the suggested benefits of dietary supplementation for immune function in healthy, well nourished subjects. Such studies are hampered by large variability in immune function markers and clinical outcome measures, which are known to be affected by factors such as genotype, age, gender, history of infections and vaccinations, and various stressors associated with lifestyle. Therefore, there appears to be a need to employ experimental models that control and/or manipulate the factors that are responsible for this variability. Conceivably, such a model could experimentally apply various forms of stress to physiologically suppress the immune system and assess whether nutritional intervention can (partially) compensate the deleterious effects. Here we review effects of psychological stress, physical exertion, and sleep deprivation on various aspects of immune function and susceptibility to common infections. We focus on the usefulness of such stress models to evaluate the putative beneficial role of diets/nutrients on immune function in healthy individuals.

Pain, psychological variables, sleep quality, and natural killer cell activity in midlife women with and without fibromyalgia

In women with fibromyalgia (FM), central nervous system (CNS) dysfunction in pain, mood, and sleep processes could be associated with changes in immune system indicators. The primary purpose of this study was to compare pain, psychological variables, subjective and objective sleep quality, lymphocyte phenotypes and activation markers, and natural killer activity (NKA) in midlife women with and without FM. A secondary purpose was to explore relationships among these variables in a step-wise regression. Subjects had pain pressure tender points assessed, completed a psychiatric interview and questionnaires (Beck Depression Inventory, SCL-90, Profile of Mood States, subjective sleep), and underwent polysomnograhic assessment for two consecutive nights. Lymphocyte phenotypes, activation markers, and NKA were assessed from blood drawn the morning after sleep laboratory night 2. Compared to controls, women with FM had lower pain thresholds, more psychological distress, higher depression scores, and reduced subjective and objective sleep quality. They also had fewer NK cells (p <.009) and more NK cells that expressed the IL-2 receptor (p <.04), but these differences were not statistically significant after correction for multiple comparisons. NKA was not statistically significantly lower in the women with FM compared to controls. In a multiple regression of age, tender point threshold, depression, psychological distress, and sleep efficiency, only the effect of group was significant (F = 5.479, p <.03) on NKA. In conclusion, we found little evidence to support the hypothesis that pain, mood, and sleep symptoms are associated with changes in the enumeration of peripheral lymphocytes or function in FM.

Role of stress, arousal, and coping skills in primary insomnia

OBJECTIVE

Although stress is often presumed to cause sleep disturbances, little research has documented the role of stressful life events in primary insomnia. The present study examined the relationship of stress and coping skills, and the potential mediating role of presleep arousal, to sleep patterns in good sleepers and insomnia sufferers.

METHODS

The sample was composed of 67 participants (38 women, 29 men; mean age, 39.6 years), 40 individuals with insomnia and 27 good sleepers. Subjects completed prospective, daily measures of stressful events, presleep arousal, and sleep for 21 consecutive days. In addition, they completed several retrospective and global measures of depression, anxiety, stressful life events, and coping skills.

RESULTS

The results showed that poor and good sleepers reported equivalent numbers of minor stressful life events. However, insomniacs rated both the impact of daily minor stressors and the intensity of major negative life events higher than did good sleepers. In addition, insomniacs perceived their lives as more stressful, relied more on emotion-oriented coping strategies, and reported greater presleep arousal than good sleepers. Prospective daily data showed significant relationships between daytime stress and nighttime sleep, but presleep arousal and coping skills played an important mediating role.

CONCLUSIONS

The findings suggest that the appraisal of stressors and the perceived lack of control over stressful events, rather than the number of stressful events per se, enhance the vulnerability to insomnia. Arousal and coping skills play an important mediating role between stress and sleep. The main implication of these results is that insomnia treatments should incorporate clinical methods designed to teach effective stress appraisal and coping skills.