Interactions between evening and nocturnal cortisol secretion and sleep parameters in patients with severe chronic primary insomnia

Brain-derived neurotrophic factor is a biomarker for subjective insomnia but not objectively assessable poor sleep continuity

OBJECTIVES

Brain-derived neurotrophic factor (BDNF) is a central mediator of the effects of stress on neuronal plasticity. Patients with subjective insomnia have significantly lower serum BDNF (sBDNF) levels. The aims of the present study were to investigate the associations of sBDNF with, 1) subjective and 2) objective sleep; 3) to investigate the associations between dimensions of psychopathology, subjective sleep and sBDNF, and 4) to investigate the associations between insomnia, sBDNF and cortisol.

METHODS

60 patients with insomnia (IG; mean age: 40.4 years; 48.3% females) and 30 healthy, age and gender-matched controls (CG) took part in the study. Subjective sleep was assessed using the Insomnia Severity Index (ISI), objective sleep was assessed once via sleep-EEG recordings. Both sBDNF and salivary cortisol were sampled once the following morning. Last, experts rated participants' symptoms of depression and anxiety.

RESULTS

sBDNF was significantly lower in the IG than in the CG (large effect size; Hedge's g = 1.75), while higher insomnia scores, but not depression or anxiety ratings, predicted lower sBDNF levels. Concerning objective sleep, low sBDNF did not correlate with sleep continuity measures, but with decreased REM-sleep; the latter was also characteristic of the IG. sBDNF and salivary morning cortisol were unrelated.

CONCLUSIONS

Independently of symptoms of depression or anxiety, sBDNF appears to be a biomarker for the clinical diagnosis of insomnia, but not for objectively assessed poor sleep continuity. A possible link between sBDNF and insomnia seems to be via regulation of REM-sleep, but not salivary morning cortisol.

Poor night's sleep predicts following day's salivary alpha-amylase under high but not low stress

Although sleep is linked to physiological stress systems like the autonomic nervous system (ANS), research is still limited regarding night-and-day interactions between nocturnal sleep characteristics, stress, and diurnal parameters of salivary alpha-amylase (sAA) as a surrogate marker of ANS activity. Fifty healthy university students rated their chronic stress burden and completed two five-day periods of ecological momentary assessment - under everyday conditions of both low stress (beginning of semester) and high stress (final examination preparation). Participants collected saliva six times daily and reported on the previous night's sleep (quality, latency, duration, disturbances) immediately after awakening. Additionally, a sub-sample wore actigraphs recording 'time in bed'. In contrast to previous assumptions, poor sleep predicted lower sAA awakening values, more decreased awakening responses, and steeper diurnal slopes the following day only under high stress, but not under low stress. Diurnal sAA parameters did not predict the following night's sleep characteristics. The sAA profile does not seem to be sensitive to everyday occurring sleep variations, but rather seems to be an indicator of more prolonged stress induced ANS dysregulation.

Association of sleep problems with neuroendocrine hormones and coagulation factors in patients with acute myocardial infarction

Background

Obstructive sleep apnea (OSA) and insomnia are frequent sleep problems that are associated with poor prognosis in patients with coronary heart disease. The mechanisms linking poor sleep with an increased cardiovascular risk are incompletely understood. We examined whether a high risk of OSA as well as insomnia symptoms are associated with neuroendocrine hormones and coagulation factors in patients admitted with acute myocardial infarction.

Methods

We assessed 190 patients (mean age 60 years, 83% men) in terms of OSA risk (STOP screening tool for the assessment of high vs. low OSA risk) and severity of insomnia symptoms (Jenkins Sleep Scale for the assessment of subjective sleep difficulties) within 48 h of an acute coronary intervention. Circulating concentrations of epinephrine, norepinephrine, cortisol, fibrinogen, D-dimer, and von Willebrand factor were measured the next morning. The association of OSA risk and insomnia symptoms with neuroendocrine hormones and coagulation factors was computed using multivariate models adjusting for demographic factors, health behaviors, somatic and psychiatric comorbidities, cardiac disease-related variables, and OSA risk in the model for insomnia symptoms, respectively, for insomnia symptoms in the model for OSA risk.

Results

High OSA risk was identified in 41% of patients and clinically relevant insomnia symptoms were reported by 27% of patients. Compared to those with low OSA risk, patients with high OSA risk had lower levels of epinephrine (p = 0.015), norepinephrine (p = 0.049) and cortisol (p = 0.001). More severe insomnia symptoms were associated with higher levels of fibrinogen (p = 0.037), driven by difficulties initiating sleep, and with lower levels of norepinephrine (p = 0.024), driven by difficulties maintaining sleep.

Conclusions

In patients with acute myocardial infarction, sleep problems are associated with neuroendocrine hormones and coagulation activity. The pattern of these relationships is not uniform for patients with a high risk of OSA and those with insomnia symptoms, and whether they contribute to adverse cardiovascular outcomes needs to be established.

Trial registration

ClinicalTrials.gov NCT01781247.

Sleep Architecture and Hypothalamic-Pituitary-Adrenal Activity in Paradoxical and Psychophysiological Insomnia

Introduction:

There are controversial reports about association between sleep and Hypothalamic-Pituitary-Adrenal (HPA) activity. Studies have reported the influence of insomnia on HPA hormones. However, they usually ignored the heterogeneity of insomnia symptoms, so subtypes of the disorder have not been considered in the reports. The present study aimed to investigate the final and intermediate products of HPA system among a group of psychophysiological and paradoxical insomniac patients in comparison to a group of normal sleepers.

Methods:

We investigated the awakening serum level of Adrenocorticotropic Hormone (ACTH) and cortisol after one night Polysomnography (PSG) in 17 subjects with psychophysiological insomnia, 19 subjects with paradoxical insomnia and 17 subjects with normal sleep profile. Groups were matched for age and Body Mass Index (BMI). Serum levels of ACTH and cortisol were measured by Enzyme-Linked Immunosorbent Assay (ELISA) method.

Results:

Although, a tendency toward elevation of both ACTH and cortisol was observed among patients with paradoxical insomnia compared to both control and psychophysiological insomnia, the differences were not significant comparing three groups. According to regression analysis, higher Non-Rapid Eye Movement sleep (NREM) arousal and Pulse Transit Time (PTT) significantly predicted higher level of ACTH.

Conclusion:

These findings could suggest the personality traits hypothesis for paradoxical insomnia. Both cortical and subcortical arousal could lead to more HPA activity and higher ACTH level. Further studies are recommended to confirm the hypothesis.

Altered ultradian cortisol rhythmicity as a potential neurobiologic substrate for chronic insomnia

Chronic insomnia is highly prevalent and associated with significant morbidity (i.e., confers risk for multiple psychiatric and medical disorders, such as depression and hypertension). Therefore, it is essential to identify factors that perpetuate this disorder. One candidate factor in the neurobiology of chronic insomnia is hypothalamic-pituitary-adrenal-axis dysregulation, and in particular, alterations in circadian cortisol rhythmicity. Cortisol secretory patterns, however, fluctuate with both a circadian and an ultradian rhythm (i.e., pulses every 60-120 min). Ultradian cortisol pulses are thought to be involved in the maintenance of wakefulness during the day and their relative absence at night may allow for the consolidation of sleep and/or shorter nocturnal awakenings. It is possible that the wakefulness that occurs in chronic insomnia may be associated with the aberrant occurrence of cortisol pulses at night. While cortisol pulses naturally occur with transient awakenings, it may also be the case that cortisol pulsatility becomes a conditioned phenomenon that predisposes one to awaken and/or experience prolonged nocturnal awakenings. The current review summarizes the literature on cortisol rhythmicity in subjects with chronic insomnia, and proffers the suggestion that it may be abnormalities in the ultradian rather than circadian cortisol that is associated with the pathophysiology of insomnia.

Night Games and Sleep: Physiological, Neuroendocrine, and Psychometric Mechanisms

Context: Night games are a regular occurrence for team-sport athletes, yet sleep complaints following night competitions are common. The mechanisms responsible for reported sleep difficulty in athletes are not understood. Methods: An observational crossover design investigating a night netball game and a time-matched rest day in 12 netball athletes was conducted to ascertain differences in physiological (core temperature), psychometric (state and trait), and neuroendocrine (adrenaline, noradrenaline, and cortisol) responses. Results: Following the night game, athletes experienced reduced sleep durations, lower sleep efficiency, early awakenings, and poorer subjective sleep ratings compared with the rest day. No differences were found between core temperature, state psychometric measures, and cortisol at bedtime. Adrenaline and noradrenaline concentrations were elevated compared with the time-matched rest day prior to (26.92 [15.88] vs 12.90 [5.71] and 232.6 [148.1] vs 97.83 [36.43] nmol/L, respectively) and following the night game (18.67 [13.26] vs 11.92 [4.56] and 234.1 [137.2] vs 88.58 [54.08] nmol/L, respectively); however, the concentrations did not correlate to the sleep variables (duration, efficiency, and sleep-onset latency). A correlation (rs = −.611) between sleep efficiency and hyperarousal (trait psychometric measure) was found. Conclusions: Athletes experienced poor sleep following a night game. Furthermore, results suggest that athletes who have a tendency toward a high trait arousal may be more susceptible to sleep complaints following a night game. These data expand knowledge and refute frequently hypothesized explanations for poor sleep following night competition. The results may also help support staff and coaches target strategies for individual athletes at a higher risk of sleep complaints.

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.

Familial Risk for Insomnia Is Associated With Abnormal Cortisol Response to Stress

Objectives

Abnormalities in the stress system have been implicated in insomnia. However, studies examining physiological stress regulation in insomnia have not consistently detected differences in the hypothalamic-pituitary-adrenal (HPA)-axis response to stress. One explanation may be that deficits in the stress system are associated specifically with a biological vulnerability to insomnia rather than the phenotypic expression of insomnia. To examine stress response as a function of vulnerability to insomnia, this study tested response to the Trier Social Stress Test in a sample of healthy sleepers with varying familial risks for insomnia.

Methods

Thirty-five healthy individuals with and without familial risk for insomnia were recruited to complete a laboratory stressor. Participants with one or both biological parents with insomnia were categorized as positive for familial risk, whereas those without biological parents with insomnia were categorized as negative for familial risk. Participants completed the Trier Social Stress Test in the laboratory, and psychological and physiological (autonomic and HPA-axis) responses were compared.

Results

Despite self-reported increases in anxiety, those positive for familial risk exhibited a blunted cortisol response relative to those without familial risk for insomnia. Individuals with blunted cortisol also reported heightened reactivity to personal life stressors, including increased sleep disturbances, elevated cognitive intrusions, and more behavioral avoidance.

Conclusions

Findings from this study provide initial evidence that abnormal stress regulation may be a biological predisposing factor conferred via familial risk for insomnia. This deficit may also predict negative consequences over time, including insomnia and the associated psychiatric comorbidities.

Insomnia Symptoms Are Associated With Abnormal Endothelial Function

BACKGROUND

Insomnia is a prevalent sleep disorder, and it has been increasingly associated with cardiovascular morbidity and mortality. The reasons for this relationship are not completely understood but may involve endothelial dysfunction. In this study, we hypothesized that insomnia symptoms would be associated with reduced endothelial function.

METHODS

Working adults (n = 496, 67.5% female, 78.6% white, mean age 48.7 [SD, 10.8] years, body mass index 28.2 [SD, 6.7] kg/m, diabetes 5.8%, hypertension 20.0%, hyperlipidemia 17.9%, heart disease 2.6%) enrolled in the Emory-Georgia Tech Predictive Health Institute study completed baseline demographic, clinical, depression (Beck Depression Inventory II), anxiety (General Anxiety Disorder 7), sleep (Pittsburg Sleep Quality Index), and noninvasive endothelial function (brachial artery flow-mediated dilation [FMD]) measures. Insomnia symptoms were defined as subjective sleep latency of 30 minutes or longer, nighttime or early morning awakenings, and/or sleep medication use occurring 3 times or more per week in the past month.

RESULTS

Insomnia symptoms were reported by 39.5% of participants. Multivariable regression models showed that insomnia symptoms, age, baseline artery diameter, and dyslipidemia were inversely related to FMD. After adjusting for age, baseline artery diameter, and dyslipidemia, participants reporting insomnia symptoms had lower FMD than did participants reporting better sleep (adjusted FMD mean, 6.13% [SD, 0.28%] vs 6.83% [SD, 0.26%], P = .035).

CONCLUSION

In this study, insomnia symptoms were associated with reduced FMD. Research examining the therapeutic benefits of treating insomnia on endothelial function and future cardiovascular risk is warranted.

Altered nocturnal blood pressure profiles in women with insomnia disorder in the menopausal transition

OBJECTIVE

Insomnia disorder is a risk factor for cardiovascular (CV) pathology. It is unknown whether insomnia that develops in the context of the menopausal transition (MT) impacts the CV system. We assessed nocturnal blood pressure (BP) and heart rate (HR) profiles in women with insomnia disorder in the MT.

METHODS

Twelve women meeting DSM-IV criteria for insomnia in the MT (age, mean ± SD: 50.5 ± 3.6 y) and 11 controls (age, mean ± SD: 49.0 ± 3.0 y) had polysomnographic recordings on one or two nights during which beat-to-beat BP and HR were assessed and analyzed hourly from lights-out across the first 6 hours of the night and according to sleep stage. Physiological hot flashes were identified from fluctuations in sternal skin conductance.

RESULTS

Women with insomnia and controls had similar distributions of sleep stages and awakenings/arousals across hours of the night, although insomnia participants tended to have more wakefulness overall. More women in the insomnia group (7 of 12) than in the control group (2 of 11) had at least one physiological hot flash at night (P < 0.05). Both groups showed a drop in BP in the first part of the night; however, systolic and diastolic BP patterns diverged later, remaining low in controls but increasing in insomnia participants 4 to 6 hours after lights-out (P < 0.05). Both groups showed a similar pattern of decline in HR across the night.

CONCLUSIONS

Our findings suggest altered regulatory control of BP during sleep in the MT insomnia. The causes and long-term consequences of this altered nocturnal BP profile remain to be determined.

Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa?

Decades of research have reported only weak associations between the intakes of specific foods or drinks and weight gain and obesity. Randomized controlled dietary intervention trials have only shown very modest effects of changes in nutrient intake and diet composition on body weight in obese subjects. This review summarizes the scientific evidence on the role mental stress (either in or not in association with impaired sleep) may play in poor sleep, enhanced appetite, cravings and decreased motivation for physical activity. All these factors contribute to weight gain and obesity, possibly via decreasing the efficacy of weight loss interventions. We also review evidence for the role that lifestyle and stress management may play in achieving weight loss in stress-vulnerable individuals with overweight.

Hyperarousal during sleep in untreated primary insomnia sufferers: A polysomnographic study

Because some evidence favors the hyperarousal model of insomnia, we sought to learn more about the dynamics of this phenomenon during sleep. Polysomnographic data from 30 normative subjects and 86 untreated primary insomnia sufferers recruited from the database of the sleep laboratory were studied for whole nights and in terms of thirds of the night. Untreated primary insomnia sufferers had an increased sleep latency and excess of WASO, together with a deficit in REM and NREM sleep during the entire night. In terms of thirds of the night, they presented a major excess of WASO during the first and last thirds of the night but an excess of lesser importance during the middle third. A deficit in SWS was found during the first third of the night, but for REM, the deficit was present during both the first and last thirds. Primary insomnia sufferers had no SWS or REM deficit during the second third of the night. We found that the hyperarousal phenomenon occurs mainly during the sleep-onset period of the first and last thirds of the night and is less important during the middle third. These results open new avenues for understanding the pathophysiology of primary insomnia.

Impact of the Metabolic Syndrome on Mortality is Modified by Objective Short Sleep Duration

BACKGROUND

To examine whether objective sleep duration is an effect modifier of the impact of metabolic syndrome (MetS) on all-cause and cardiovascular disease/cerebrovascular mortality.

METHODS AND RESULTS

We addressed this question in the Penn State Adult Cohort, a random, general population sample of 1344 men and women (48.8±14.2 years) who were studied in the sleep laboratory and followed up for 16.6±4.2 years. MetS was defined by the presence of 3 or more of obesity (≥30 kg/m2), elevated total cholesterol (≥200 mg/dL), triglycerides (≥150 mg/dL), fasting glucose (≥100 mg/dL), and blood pressure (≥130/85 mm Hg). Polysomnographic sleep duration was classified into clinically meaningful categories. Among the 1344 participants, 22.0% of them died during the follow-up. We tested the interaction between MetS and polysomnographic sleep duration on mortality using Cox proportional hazard models controlling for multiple potential confounders (P<0.05). The hazard ratios (95% CI) of all-cause and cardiovascular disease/cerebrovascular mortality associated with MetS were 1.29 (0.89-1.87) and 1.49 (0.75-2.97) for individuals who slept ≥6 hours and 1.99 (1.53-2.59) and 2.10 (1.39-3.16) for individuals who slept <6 hours. Interestingly, this effect modification was primarily driven by the elevated blood pressure and glucose dysregulation components of MetS.

CONCLUSIONS

The risk of mortality associated with MetS is increased in those with short sleep duration. Short sleep in individuals with MetS may be linked to greater central autonomic and metabolic dysfunction. Future clinical trials should examine whether lengthening sleep improves the prognosis of individuals with MetS.

Objective short sleep duration modifies the relationship between hypertension and all-cause mortality

OBJECTIVE

Short sleep duration has been associated with cardiovascular morbidity and mortality. However, previous studies were limited by using subjective sleep measures and treating sleep duration as a sole, independent predictor. Therefore, the role of sleep duration in predicting mortality is still not well understood. We posit that objective sleep duration is an effect modifier of the relationship between hypertension and all-cause mortality.

METHODS

We addressed this question in the Penn State Adult Cohort, a random, general population sample of 1741 men and women (48.7 ± 13.5 years) who were studied in the sleep laboratory and followed up for 15.5 ± 4.1 years. Hypertension was defined on the basis of SBP and DBP (≥140/≥90 mmHg) or use of antihypertensive medication. Polysomnographic sleep duration was classified into three clinically meaningful categories.

RESULTS

We tested the interaction between hypertension and polysomnographic sleep duration on all-cause mortality using multiple logistic regression while controlling for several potential confounders (P value = 0.03). The odds (95% confidence interval) of all-cause mortality associated with hypertension were 1.77 (1.07-2.92), 2.78 (1.47-5.24), and 3.93 (2.22-6.95) for individuals who slept at least 6, 5-6, and 5 h or less, respectively.

CONCLUSION

The risk of mortality associated with hypertension increases in a dose-response manner as a function of shorter sleep duration. Short sleep in hypertensive individuals may be a marker of the degree of central autonomic dysfunction. Future epidemiological studies should examine this effect modification using cause-specific mortality, whereas future clinical trials should examine whether lengthening sleep improves the prognosis of individuals with hypertension.

Hyperarousal and Beyond: New Insights to the Pathophysiology of Insomnia Disorder through Functional Neuroimaging Studies

Neuroimaging studies have produced seemingly contradictory findings in regards to the pathophysiology of insomnia. Although most study results are interpreted from the perspective of a "hyperarousal" model, the aggregate findings from neuroimaging studies suggest a more complex model is needed. We provide a review of the major findings from neuroimaging studies, then discuss them in relation to a heuristic model of sleep-wake states that involves three major factors: wake drive, sleep drive, and level of conscious awareness. We propose that insomnia involves dysregulation in these factors, resulting in subtle dysregulation of sleep-wake states throughout the 24 h light/dark cycle.

Stress Reactivity in Insomnia

This study examined whether individuals with primary insomnia (PI) are more reactive to stress than good sleepers (GS). PI and GS (n = 20 per group), matched on gender and age, completed three nights of polysomnography. On the stress night, participants received a mild electric shock and were told they could receive additional shocks during the night. Saliva samples were obtained for analysis of cortisol and alpha amylase along with self-report and visual analog scales (VAS). There was very little evidence of increased stress on the stress night, compared to the baseline night. There was also no evidence of greater stress reactivity in the PI group for any sleep or for salivary measures. In the GS group, stress reactivity measured by VAS scales was positively associated with an increase in sleep latency in the experimental night on exploratory analyses. Individuals with PI did not show greater stress reactivity compared to GS.

Successful physical exercise-induced weight loss is modulated by habitual sleep duration in the elderly: results of a pilot study

Although it is widely accepted that physical exercise promotes weight loss, physical exercise alone had been found to result in only marginal weight loss compared to no treatment. Interestingly, both subjective and objective sleep duration have been shown to be negatively correlated to the body mass index (BMI). Despite this growing evidence of a relation between sleep duration and body weight, the role of habitual sleep duration in physical exercise-induced weight loss has not been studied so far. Twenty-two healthy elderly good sleepers aged 61-76 years (mean 68.36 years, 55 % female, BMI mean 25.15 kg/m²) either took part in a 12-week aerobic endurance training (3 × 30 min/week) or in a relaxation control (2 × 45 min/week). The BMI was assessed prior to and after intervention. Subjects maintained sleep logs every morning/evening during the training period, allowing for calculation of habitual sleep duration. Besides a significant main effect of the type of training, a significant interaction of type of training and habitual sleep duration was observed: while after treadmill training subjects who slept less than 7.5 h/night during intervention reduced their BMI by nearly 4 %, a comparable decrease in the BMI was found neither in subjects who slept more than 7.5 h nor after relaxation training independent of sleep duration. Sleep duration itself did not change in any group. Although results should be interpreted with caution due to the small sample size, this is the first study to indicate that physical exercise might compensate for disturbed body weight regulation associated with short sleep duration.

The Association Between Insomnia and Increased Future Cardiovascular Events: A Nationwide Population-Based Study

OBJECTIVES

Insomnia may increase the risk of cardiovascular disease (CVD), but the reported magnitude of the associations between sleep characteristics and CVD is inconsistent. We investigated the association between insomnia and the risk of developing acute myocardial infarction (AMI) and/or stroke by using a nationwide, population-based cohort database in Taiwan.

METHODS

The analyses were conducted using information from a random sample of 1 million people enrolled in the nationally representative Taiwan National Health Insurance Research Database. A total of 44,080 individuals who were 20 years or older, including 22,040 people who had diagnosis of insomnia during the study period and an age-, sex-, comorbidity-matched group of 22,040 people without insomnia, were enrolled in our study. The study end points were the occurrence of cardiovascular events including AMI or stroke during follow-up.

RESULTS

During a 10-year follow-up, 302 AMI events and 1049 stroke events were identified. The insomnia group had a higher incidence of AMI (2.25 versus 1.08 per 1000 person-years) and stroke (8.01 versus 3.69 per 1000 person-years, p < .001). Cox proportional hazard regression model analysis showed that insomnia was independently associated with a higher risk of future AMI (hazard ratio [HR] = 1.68, 95% confidence interval [CI] = 1.31-2.16, p < .001), stroke (HR = 1.85, 95% CI = 1.62-2.12, p < .001), and the composite event index (HR = 1.81, 95% CI = 1.61-2.05, p < .001), after adjusting for age, sex, and comorbidities.

CONCLUSIONS

Insomnia is associated with an increased risk of future cardiovascular events.

Association of Sleep Duration and Quality With Alterations in the Hypothalamic-Pituitary Adrenocortical Axis: The Multi-Ethnic Study of Atherosclerosis (MESA)

CONTEXT

Short sleep duration and poor sleep quality are associated with cardiovascular outcomes. One mechanism proposed to explain this association is altered diurnal cortisol secretion.

OBJECTIVE

The objective of the study was to examine the associations of sleep duration and sleep quality with diurnal salivary cortisol levels.

DESIGN

This was a cross-sectional analysis using data from examination 5 (2010-2012) of the Multi-Ethnic Study of Atherosclerosis. Actigraphy-based measures of sleep duration and efficiency were collected over 7 days, and salivary cortisol samples were collected over 2 days from participants aged 54-93 years (n = 600 with analyzable data).

RESULTS

Shorter average sleep duration (<6 h/night) was associated with less pronounced late decline in cortisol [2.2% difference in slope; 95% confidence interval (CI) 0.8-3.7; P ≤ .01] and less pronounced wake-to-bed slope (2.2% difference; 95% CI 1.0-3.4; P ≤ .001) compared with longer sleep duration (≥6 h/night). Lower sleep efficiency (<85%) was associated with less pronounced early decline in cortisol (29.0% difference in slope; 95% CI 4.1-59.7; P < .05) compared with higher sleep efficiency (≥85%). Subjects reporting insomnia had a flatter cortisol awakening response (-16.1% difference in slope; 95% CI -34.6 to -0.1; P < .05) compared with those not reporting insomnia.

CONCLUSIONS

Shorter sleep duration, lower sleep efficiency, and insomnia are associated with alterations in diurnal cortisol levels consistent with changes in hypothalamic-pituitary-adrenal regulation.

Sleep disturbances, TBI and PTSD: Implications for treatment and recovery

Post-Traumatic Stress Disorder (PTSD), traumatic brain injury (TBI), and sleep problems significantly affect recovery and functional status in military personnel and Veterans returning from combat. Despite recent attention, sleep is understudied in the Veteran population. Few treatments and rehabilitation protocols target sleep, although poor sleep remains at clinical levels and continues to adversely impact functioning even after the resolution of PTSD or mild TBI symptoms. Recent developments in non-pharmacologic sleep treatments have proven efficacious as stand-alone interventions and have potential to improve treatment outcomes by augmenting traditional behavioral and cognitive therapies. This review discusses the extensive scope of work in the area of sleep as it relates to TBI and PTSD, including pathophysiology and neurobiology of sleep; existing and emerging treatment options; as well as methodological issues in sleep measurements for TBI and PTSD. Understanding sleep problems and their role in the development and maintenance of PTSD and TBI symptoms may lead to improvement in overall treatment outcomes while offering a non-stigmatizing entry in mental health services and make current treatments more comprehensive by helping to address a broader spectrum of difficulties.

Objective short sleep duration is associated with the activity of the hypothalamic-pituitary-adrenal axis in insomnia

Objective To evaluate the association between objective short sleep duration in patients with insomnia and changes in blood parameters related to hypothalamic-pituitary-adrenal (HPA) axis activity.Method A cross-sectional pilot study was conducted in 30 middle-aged adults with chronic insomnia who were divided into 2 groups according to polysomnography (PSG) total sleep time (TST) (TST > 5h and < 5h). All patients underwent subjective analysis of sleep quality, anthropometric measurements, PSG, and determination off asting blood parameters.Results The results revealed lower sleep efficiency and higher sleep latency for those with a TST < 5h. The subjective sleep quality was worse in the TST < 5h. Significantly, higher glucose and cortisol levels were observed with a TST < 5h. Glucose, cortisol and ACTH levels were inversely correlated with the PSG total sleep time.Conclusion Patients with insomnia with objective short sleep duration had HPA-associated endocrine and metabolic imbalances chronically linked to increases in cardiovascular risk observed with this more severe insomnia phenotype.

Sleep characteristics as predictor variables of stress systems markers in insomnia disorder

This study investigates the extent to which sleep characteristics serve as predictor variables for inflammatory, hypothalamic-pituitary-adrenal and autonomic systems markers. Twenty-nine participants with a diagnosis of insomnia disorder based on the Diagnostic Statistical Manual of Mental Disorders, Fifth Edition (age 25.3 ± 1.6 years, insomnia duration 6.6 ± 0.8 years) and 19 healthy control sleepers (age 25.4 ± 1.4 years) underwent a 2-week at-home evaluation keeping a sleep diary and wearing an actigraph, followed by a visit to the Research Center to measure blood pressure, and collect blood and urine samples. The actigraphy- and diary-based variables of sleep duration, sleep-onset latency, wake after sleep onset and sleep fragmentation/number of night-time awakenings were averaged and entered as dependent variables in regression analyses. Composite scores were calculated for the autonomic (blood pressure, norepinephrine), inflammatory (monocyte counts, interleukin-6, C-reactive protein) and hypothalamic-pituitary-adrenal systems (cortisol), and used as predictor variables in regression models. Compared with controls, individuals with insomnia had a shorter sleep duration (P < 0.05), and a higher hypothalamic-pituitary-adrenal and inflammatory composite score (P < 0.05). The higher inflammatory score was mainly due to higher circulating monocytes (P < 0.05), rather than differences in interleukin-6 or C-reactive protein. In persistent insomnia disorder, cortisol is upregulated and associated with actigraphy- and diary-based wake after sleep onset, suggesting that wake after sleep onset may serve as a marker to identify individuals at increased risks for disorders associated with a hyperactive hypothalamic-pituitary-adrenal system. The absence of autonomic and pro-inflammatory changes (interleukin-6, C-reactive protein), despite a substantial decrease in actigraphic sleep duration, may relate to a higher resilience to the adverse biological consequences of insomnia in this young age group.

Effects of sleep deprivation on serum cortisol level and mental health in servicemen

This study aimed to investigate the effects of sleep deprivation on serum cortisol level and mental health and explore the correlations between them in servicemen. A total of 149 out of the 207 Chinese servicemen were randomly selected to go through 24hour sleep deprivation, leaving the rest (58) as the control group, before and after which their blood samples were drawn for cortisol measurement. Following the procedure, all the participants were administered the Military Personnel Mental Disorder Prediction Scale, taking the military norm as baseline. The results revealed that the post-deprivation serum cortisol level was positively correlated with the factor score of mania in the sleep deprivation group (rSp=0.415, p<0.001). Sleep deprivation could significantly increase serum cortisol level and may affect mental health in servicemen. The increase of serum cortisol level is significantly related to mania disorder during sleep deprivation.

The pathophysiology of insomnia

Insomnia disorder is characterized by chronic dissatisfaction with sleep quantity or quality that is associated with difficulty falling asleep, frequent nighttime awakenings with difficulty returning to sleep, and/or awakening earlier in the morning than desired. Although progress has been made in our understanding of the nature, etiology, and pathophysiology of insomnia, there is still no universally accepted model. Greater understanding of the pathophysiology of insomnia may provide important information regarding how, and under what conditions, the disorder develops and is maintained as well as potential targets for prevention and treatment. The aims of this report are (1) to summarize current knowledge on the pathophysiology of insomnia and (2) to present a model of the pathophysiology of insomnia that considers evidence from various domains of research. Working within several models of insomnia, evidence for the pathophysiology of the disorder is presented across levels of analysis, from genetic to molecular and cellular mechanisms, neural circuitry, physiologic mechanisms, sleep behavior, and self-report. We discuss the role of hyperarousal as an overarching theme that guides our conceptualization of insomnia. Finally, we propose a model of the pathophysiology of insomnia that integrates the various types of evidence presented.

Road traffic noise and markers of obesity - a population-based study

BACKGROUND

Noise has been found to be associated with endocrine changes and cardiovascular disease. Increased cortisol levels and chronic sleep problems due to noise may increase the risk of obesity.

OBJECTIVES

We investigated the relationship between road traffic noise and obesity markers. Furthermore, we explored the modifying role of noise sensitivity, noise annoyance, and sleep disturbances.

METHODS

We used data from a population-based study, HUBRO (N=15,085), and its follow-up study HELMILO (N=8410) conducted in Oslo, Norway. Measurements were used to define body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and these binary outcomes: BMI≥30kg/m(2), WC≥102cm (men)/88cm (women), and WHR≥0.90 (men)/0.85 (women). Modelled levels of road traffic noise (Lden) were assigned to each participant's home address. Linear and logistic regression models were used to examine the associations.

RESULTS

The results indicated no significant associations between road traffic noise and obesity markers in the total populations. However, in highly noise sensitive women (n=1106) a 10dB increase in noise level was associated with a slope (=beta) of 1.02 (95% confidence interval (CI): 1.01, 1.03) for BMI, 1.01 (CI: 1.00, 1.02) for WC, and an odds ratio (OR) of 1.24 (CI: 1.01, 1.53) for WHR ≥0.85. The associations appeared weaker in highly noise sensitive men. We found no effect modification of noise annoyance or sleep disturbances. In a sub-population with bedroom facing a road, the associations increased in men (e.g. an OR of 1.25 (CI: 0.88, 1.78) for BMI ≥30kg/m(2)), but not in women. Among long-term residents the associations increased for BMI ≥30kg/m(2) (OR of 1.07 (CI: 0.93, 1.24) in men and 1.10 (CI: 0.97, 1.26) in women), but not for the other outcomes.

CONCLUSION

In an adult urban Scandinavian population, road traffic noise was positively associated with obesity markers among highly noise sensitive women. The associations appeared stronger among men with bedroom facing a street, representing a population with more accurately assigned exposure.

Coping mediates the effects of depressive symptoms on sleep problems

OBJECTIVES

To explore the relationships of perceived stress and depressive symptoms to sleep problems, testing for mediation by adaptive and maladaptive coping strategies.

METHODS

Alternative high school students (N = 1676) completed self-report surveys. Cross-sectional data were analyzed via Preacher and Hayes' procedures for multiple mediation.

RESULTS

The positive relationship between depressive symptoms and sleep problems was mediated partially by anger coping (positively related to sleep problems). The positive relationship between perceived stress and sleep problems was not mediated by coping strategies.

CONCLUSIONS

Findings provide information on psychological factors that may lead to poor sleep outcomes, and are useful for developing health promotion interventions to impact lifelong health behaviors.

Trauma-induced insomnia: A novel model for trauma and sleep research

Traumatic events have been increasingly recognized as important precipitants of clinically significant insomnia. Trauma is an extreme form of stressful life event that generates a sustained neurobiological response triggering the onset and maintenance of insomnia. Trauma may disrupt the normal sleep-wake regulatory mechanism by sensitizing the central nervous system's arousal centers, leading to pronounced central and physiological hyperarousal. The central concept of hyperarousal has been linked to both the pathogenesis of insomnia and to the neurobiological changes in the aftermath of traumatic events, and may be a neurobiological commonality underlying trauma and insomnia. This paper presents evidence for trauma-induced insomnia and advances a model of it as an important nosological and neurobiological entity. Trauma-induced insomnia may occur in the absence of full-blown posttraumatic stress disorder (PTSD), and may also be a precursor of subsequent PTSD development. Converging lines of evidence from the neuroscience of insomnia with the neurobiology and psychophysiology of stress, fear, trauma and PTSD will be integrated to advance understanding of the condition. Preclinical and clinical stress and fear paradigms have informed the neurobiological pathways mediating the production of insomnia by trauma. Elucidating the underlying neurobiological substrates can establish novel biological markers to identify persons at risk for the condition, and help optimize treatment of the trauma-insomnia interface. Early identification and treatment of trauma-induced insomnia may prevent the development of PTSD, as well as other important sequelae such as depression, substance dependence, and other medical conditions.

Poor sleep predicts symptoms of depression and disability retirement due to depression

BACKGROUND

Disturbed sleep is associated with mood disorders. Both depression and insomnia may increase the risk of disability retirement. The longitudinal links among insomnia, depression and work incapacity are poorly known.

METHODS

We examined association of self-reported sleep quality with incident symptoms of depression and disability retirement due to depressive disorders in a longitudinal population-based sample of twins (n=12,063 individuals). These adults were categorized by their sleep quality in 1975 and 1981, excluding individuals with depressed mood in 1975/1981. The outcomes were the Beck Depression Inventory (BDItot) and its subscale Negative Attitudes Towards Self (BDINATS) in 1990 as dichotomized measures, and the incidence of disability retirement due to depressive disorder during 1991-2004.

RESULTS

Onset of poor sleep between 1975 and 1981 predicted incident depression (BDItot OR=4.5, 95% CI: 2.7-7.4, BDINATS OR=2.0, 95% CI: 1.4-2.7), while persistent poor sleep showed somewhat weaker effects (BDItot; OR=2.5, 95% CI: 1.0-6.0, BDINATS OR=1.9, 95% CI: 1.1-3.3). Among those with few recent stressful life events, onset of poor sleep predicted strongly depression (BDINATS OR=9.5, 95% CI: 3.7-24.2). Likewise onset of poor sleep by 1981 increased the risk of disability retirement due to depression (OR=2.9, 95% CI: 1.8-4.9) with a similar risk among those with persistent poor sleep (OR=2.7, 95% CI: 1.3-5.7).

LIMITATIONS

Lack of baseline diagnostic interviews; sleep quality based on self-report.

CONCLUSIONS

Poor sleep is of importance in etiology of depression and disability retirement due to depression. This emphasizes the importance of early detection and treatment of sleep disturbances.

Interaction between 5-HTTLPR genotype and cognitive stress vulnerability on sleep quality: effects of sub-chronic tryptophan administration

BACKGROUND

Abundant evidence suggests that allelic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) influences susceptibility to stress and its affective consequences due to brain serotonergic vulnerability. Based on recent assumptions, the present study examined whether the 5-HTTLPR genotype may also interact with a vulnerability to chronic stress experience (conceptualized by trait neuroticism) in order to influence sleep quality and, additionally, whether this is influenced by brain serotonergic manipulations.

METHODS

In a well-balanced experimental design, homozygous S-allele (n = 57) and L-allele (n = 54) genotypes with high and low chronic stress vulnerability (neuroticism) were first assessed for general past sleep quality during a month before onset of the experiment. Then subjects were assessed for sleep quality following 7 days of tryptophan (3.0g/day) or placebo intake.

RESULTS

Although high neuroticism was significantly related to a higher frequency of stressful life events and daily hassles, it did not interact with the 5-HTTLPR genotype on general past sleep quality. However, as expected, a 7 day period of tryptophan administration was exclusively associated with better sleep quality scores in the S'/S' genotype with high trait neuroticism.

CONCLUSIONS

Current findings suggest that 5-HTTLPR does not directly interact with stress vulnerability in order to influence sleep quality. Instead, based on current and previous findings, it is suggested that the S'/S' 5-HTTLPR genotype promotes the risk for stress-related sleep disturbances because of an increased susceptibility to the depressogenic consequences of stress. Accordingly, by way of reducing depressive symptomatology, tryptophan augmentation may particularly improve sleep quality in stress-vulnerable individuals carrying the 5-HTTLPR S-allele.

Sleep problems in children with autism spectrum disorder: examining the contributions of sensory over-responsivity and anxiety

OBJECTIVES

Children with autism spectrum disorder (ASD) are at high risk for sleep problems. Previous research suggests that sensory problems and anxiety may be related to the development and maintenance of sleep problems in children with ASD. However, the relationships among these co-occurring conditions have not been previously studied. The current study examined the interrelations of these symptoms in a large well-characterized sample of children and adolescents with ASD.

METHODS

The current study examined the relationships among sleep problems, sensory over-responsivity, and anxiety in 1347 children enrolled in the Autism Speaks Autism Treatment Network. The primary measures included the Children's Sleep Habits Questionnaire, the Child Behavior Checklist, and the Short Sensory Profile.

RESULTS

In bivariate correlations and multivariate path analyses, anxiety was associated with all types of sleep problems (ie, bedtime resistance, sleep-onset delay, sleep duration, sleep anxiety, and night wakings; p < 0.01 to p < 0.001; small to medium effect sizes). Sensory over-responsivity (SOR) was correlated with all sleep problems in bivariate analyses (p < 0.01 to p < 0.001; small effect sizes). In multivariate path models, SOR remained significantly associated with all sleep problems except night awakenings for older children, while SOR was no longer significantly associated with bedtime resistance or sleep anxiety for younger children.

CONCLUSIONS

Children with ASD who have anxiety and SOR may be particularly predisposed to sleep problems. These findings suggest that some children with ASD and sleep disturbance may have difficulties with hyperarousal. Future research using physiological measures of arousal and objective measures of sleep are needed.

The effects of eight weeks selected aerobic exercises on sleep quality of middle-aged non-athlete females

Background:

Sleep is considered as one of the most important factors, directly influencing mental and physical health components. In the last decade, low sleep quality - i.e. poor sleep - has become one of the major problems of the individuals, especially in middle-aged women. Low quality sleep also directly influences memory, functional components, nutrition, and mood.

Objectives:

This study aims to detect the effect of selected aerobic exercises on sleep quality in non-athlete middle-aged women.

Materials and Methods:

Fifteen non-athlete middle-aged women participated in this study, all of them suffered from insomnia. Pittsburgh questionnaire was used for determining sleep quality in this sample. Four indices including sleep duration, sleep disturbance, sleep latency, and sleep efficiency have been investigated through this. The period of exercises included eight weeks, three one-hour sessions each week. The sample group was trained during eight weeks through performance of selected aerobic exercises including three groups: sequential movements equip mental movement and movements on the pad. The selected protocol included performance of exercises: 10 minutes for warm up, 10 minutes for sequential movements, 20 minutes for movements by using equipment, 15 minutes for movements performed on the pad, and 5 minutes for cooling down. The exercises during the first four weeks have been presented with 60% increase of the heart rate, and 75% increase during the second four weeks. The sample group was provided with Pittsburgh questionnaire at the beginning of the exercises and the end of each week. The information of each person was registered.

Results:

The results showed that the mean of sleep duration, sleep disturbance, sleep latency, and sleep efficiency indices significantly reduced 32%, 22%, 30%, 14% and 36%, respectively. The results also showed that the trend of changes in sleep duration, sleep disturbance, sleep latency, and sleep efficiency indices had significant descending trend.

Conclusions:

We concluded that eight weeks of aerobic exercises can significantly increase sleep quality in middle-aged women.

Hippocampal substructural vulnerability to sleep disturbance and cognitive impairment in patients with chronic primary insomnia: magnetic resonance imaging morphometry

STUDY OBJECTIVES

Despite compelling evidence from animal studies indicating hippocampal subfield-specific vulnerability to poor sleep quality and related cognitive impairment, there have been no human magnetic resonance imaging (MRI) studies investigating the relationship between hippocampal subfield volume and sleep disturbance. Our aim was to investigate the pattern of volume changes across hippocampal subfields in patients with primary insomnia relative to controls.

DESIGN

Pointwise morphometry allowed for volume measurements of hippocampal regions on T1-weighted MRI.

SETTING

University hospital.

PATIENTS

Twenty-seven unmedicated patients (age: 51.2 ± 9.6 y) and 30 good sleepers as controls (50.4 ± 7.1 y).

INTERVENTIONS

N/A.

MEASUREMENTS

We compared hippocampal subfield volumes between patients and controls and correlated volume with clinical and neuropsychological features in patients.

RESULTS

Patients exhibited bilateral atrophy across all hippocampal subfields (P < 0.05 corrected). Cornu ammonis (CA) 1 subfield atrophy was associated with worse sleep quality (higher Pittsburgh Sleep Quality Index and higher arousal index of polysomnography) (r < -0.45, P < 0.005). The volume of the combined region, including the dentate gyrus (DG) and CA3-4, negatively correlated with verbal memory, verbal information processing, and verbal fluency in patients (|r| > 0.45, P < 0.05). Hemispheric volume asymmetry of this region (left smaller than right) was associated with impaired verbal domain functions (r = 0.50, P < 0.005).

CONCLUSION

Hippocampal subfield atrophy in chronic insomnia suggests reduced neurogenesis in the dentate gyrus (DG) and neuronal loss in the cornu ammonis (CA) subfields in conditions of sleep fragmentation and related chronic stress condition. Atrophy in the CA3-4-DG region was associated with impaired cognitive functions in patients. These observations may provide insight into pathophysiological mechanisms that make patients with chronic sleep disturbance vulnerable to cognitive impairment.

CITATION

Joo EY, Kim H, Suh S, Hong SB. Hippocampal substructural vulnerability to sleep disturbance and cognitive impairment in patients with chronic primary insomnia: magnetic resonance imaging morphometry.

A community-based study on the association between insomnia and hypothalamic-pituitary-adrenal axis: sex and pubertal influences

CONTEXT

The association between insomnia disorder and the hypothalamic-pituitary-adrenal (HPA) axis needs to be explored in both adults and adolescents.

OBJECTIVES

Our objective was to investigate the associations of the HPA axis (via serial salivary cortisol) with insomnia disorder and subjective and objective sleep quality in a community-based study.

DESIGN AND SETTING

This was a community-based case-control family study.

PARTICIPANTS

Participants included 205 adolescents (14.2 ± 2.8 years old, 51.7% females, and 57 with insomnia) and 244 adults (46.4 ± 4.1 years old, 52.8% females, and 69 with insomnia).

MAIN OUTCOME MEASURES

Outcome measures included a diagnostic interview for assessment of insomnia disorder, 3-day actigraphy and sleep diary, and serial salivary cortisol measurement.

RESULTS

Adults with insomnia had a significantly greater cortisol awakening response (CAR) reference to increase (CARi) but a comparable CAR reference to ground and a comparable cortisol level during afternoon and evening when compared with noninsomniac adults. The association between insomnia disorder and larger CARi was also found in adolescents at late/post puberty but not in pre/early pubertal adolescents. There was an interaction effect between sex and insomnia disorder on CARi level with adult females having larger CARi than adult males. Among subjects with insomnia disorder, those with lower subjective sleep efficiency had higher cortisol levels in the late evening (10:00 pm) in both adults and adolescents.

CONCLUSIONS

Our study suggests that a series of insomniac indices at both syndromal and symptomatic levels including clinical diagnosis and poor sleep quality are associated with dysfunction of the HPA axis. The association between insomnia and increased CARi emerges at late puberty, and the sex difference in this association occurs in adulthood but not in adolescence.

Insomnia symptoms, objective sleep duration and hypothalamic-pituitary-adrenal activity in children

BACKGROUND

Insomnia symptoms are the most common parent-reported sleep complaints in children; however, little is known about the pathophysiology of childhood insomnia symptoms, including their association with hypothalamic-pituitary-adrenal (HPA) axis activation. The objective of this study is to examine the association between parent-reported insomnia symptoms, objective short sleep duration and cortisol levels in a population-based sample of school-aged children.

DESIGN

A sample of 327 children from the Penn State Child Cohort (5-12 years old) underwent 9-h overnight polysomnography and provided evening and morning saliva samples to assay for cortisol. Objective short sleep duration was defined based on the median total sleep time (i.e., <7·7 h). Parent-reported insomnia symptoms of difficulty initiating and/or maintaining sleep were ascertained with the Pediatric Behavior Scale.

RESULTS

Children with parent-reported insomnia symptoms and objective short sleep duration showed significantly increased evening (0·33±0·03 μg/dL) and morning (1·38±0·08 μg/dL) cortisol levels. In contrast, children with parent-reported insomnia symptoms and 'normal' sleep duration showed similar evening and morning cortisol levels (0·23±0·03 μg/dL and 1·13±0·08 μg/dL) compared with controls with 'normal' (0·28±0·02 μg/dL and 1·10±0·04 μg/dL) or short (0·28±0·02 μg/dL and 1·13±0·04 μg/dL) sleep duration.

CONCLUSIONS

Our findings suggest that insomnia symptoms with short sleep duration in children may be related to 24-h basal or responsive physiological hyperarousal. Future studies should explore the association of insomnia symptoms with short sleep duration with physical and mental health morbidity.

Disturbed dreaming during the third trimester of pregnancy

OBJECTIVE

The majority of women develop sleep impairments during pregnancy, but alterations in dream experiences remain poorly understood. This study aimed to assess prospectively and comparatively the recall of dreaming and of disturbed dreaming in late pregnancy.

METHODS

Fifty-seven nulliparous, third-trimester pregnant women (mean age±SD, 28.7±4.06 years) and 59 non-pregnant controls (mean age±SD, 26.8±4.21 years) completed demographics and psychological questionnaires. A 14-day prospective home log assessed sleep and dream characteristics and the Sleep Disorders Questionnaire measured retrospective dream and disturbed dream recall.

RESULTS

Even though pregnant and non-pregnant women showed similar prospective dream recall (P=0.47), pregnant women reported prospectively more bad dreams (P=0.004). More pregnant women (21%) than non-pregnant women (7%) reported a nightmare incidence exceeding moderately severe pathology (>1/week) (P=0.03). Pregnant women also reported overall lower sleep quality (P=0.007) and more night awakenings (P=0.003). Higher prospective recall of bad dreams (r = -0.40, P=0.002) and nightmares (r = -0.32, P=0.001) both correlated with lower sleep quality in pregnant women.

CONCLUSIONS

Late pregnancy is a period of markedly increased dysphoric dream imagery that may be a major contributor to impaired sleep at this time. Further polysomnographic assessments of pregnant women are needed to clarify relationships between sleep and disturbed dream production in this population.

Hypertension and sleep: overview of a tight relationship

Autonomic cardiovascular control changes across sleep stages. Thus, blood pressure (BP), heart rate and peripheral vascular resistance progressively decrease in non-rapid eye movement sleep. Any deterioration in sleep quality or quantity may be associated with an increase in nocturnal BP which could participate in the development or poor control of hypertension. In the present report, sleep problems/disorders, which impact either the quality or quantity of sleep, are reviewed for their interaction with BP regulation and their potential association with prevalent or incident hypertension. Obstructive sleep apnea syndrome, sleep duration/deprivation, insomnia, restless legs syndrome and narcolepsy are successively reviewed. Obstructive sleep apnea is clearly associated with the development of hypertension that is only slightly reduced by continuous positive airway pressure treatment. Shorter and longer sleep durations are associated with prevalent or incident hypertension but age, gender, environmental exposures and ethnic differences are clear confounders. Insomnia with objective short sleep duration, restless legs syndrome and narcolepsy may impact BP control, needing additional studies to establish their impact in the development of permanent hypertension. Addressing sleep disorders or sleep habits seems a relevant issue when considering the risk of developing hypertension or the control of pre-existent hypertension. Combined sleep problems may have potential synergistic deleterious effects.