Weight gain and all-night EEG-sleep in anorexia nervosa

Sleep quality in eating disorders: A systematic review and meta-analysis

Eating disorders (ED) are psychological disorders characterized by dangerous eating behaviours, including protracted fasting and binge eating. Mental disorders comorbidities (e.g., anxiety and depression), as well as sleep difficulties, are common and might interfere with treatment response. This work investigated sleep quality, circadian preferences, and sleep disorders in ED patients compared to healthy controls (HC) and the impact of ED treatment on patients' sleep. A literature search on Pubmed, Web of Science, Medline, and PsychInfo included 27 studies. Random effect analyses were performed (sample eating disorders = 711; sample healthy controls = 653) and subgroup analyses were calculated based on the ED subgroups: Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder. Whole sample analyses showed poorer physiological and subjective sleep quality in patients. Subgroup analyses showed that poorer physiological sleep was present only in anorexia nervosa. Two studies reporting circadian preferences and sleep disorders showed higher evening preference in patients and no differences in apnea prevalence between patients and healthy controls, respectively. Some studies suggested that specialized eating disorder treatments (e.g., Cognitive Behavioural Therapy for ED) can improve sleep quality in patients. Although these findings highlight poorer sleep in patients with ED compared to healthy controls, the mechanisms underlying sleep alterations in eating disorders remain to be identified.

The Role of Leptin in Rodent and Human Sleep: A Transdiagnostic Approach with a Particular Focus on Anorexia Nervosa

This narrative review addressed to both clinicians and researchers aims to assess the role of hypoleptinemia in disordered sleep with a particular focus on patients with anorexia nervosa (AN). After introducing circadian rhythms and the regulation of circulating leptin, we summarize the literature on disordered sleep in patients with AN and in fasting subjects in general. We highlight novel single-case reports of substantially improved sleep within days after initiation of off-label metreleptin treatment. These beneficial effects are set in relationship to current knowledge of disordered sleep in animal models of an impaired leptin signaling. Specifically, both absolute and relative hypoleptinemia play a major role in animal models for insomnia, obstructive sleep apnea and obesity hypoventilation syndrome. We pinpoint future research required to complement our understanding of the role of leptin in sleep in patients with acute AN. Moreover, within the section clinical applications we speculate that human recombinant leptin may be useful for the treatment of treatment-resistant sleep-wake disorders, which are associated with (relative) hypoleptinemia. Overall, we stress the role of the hormone leptin in sleep.

Physical activity and sleep during the first week of anorexia nervosa inpatient care

BACKGROUND

Individuals with Anorexia Nervosa are often described as restless, hyperactive and having disturbed sleep. The result reproducibility and generalisability of these results are low due to the use of unreliable methods, different measurement methods and outcome measures. A reliable method to measure both physical activity and sleep is through accelerometry. The main purpose of the study was to quantify the physical activity and sleeping behaviour of anorexia nervosa patients. Another purpose was to increase result reproducibility and generalisability of the study.

MATERIAL AND METHODS

Accelerometer data were collected from the first week of treatment of anorexia nervosa at an inpatient ward. Raw data from the Axivity AX3© accelerometer was used with the open-source package GGIR for analysis, in the free statistical software R. Accelerometer measurements were transformed into euclidean norm minus one with negative values rounded to zero (ENMO). Physical activity measurements of interest were 24h average ENMO, daytime average ENMO, inactivity, light activity, moderate activity, and vigorous activity. Sleep parameters of interest were sleep duration, sleep efficiency, awakenings, and wake after sleep onset. The sleep duration of different age groups was compared to recommendations by the National Sleep Foundation using a Fisher's exact test.

RESULTS

Of 67 patients, due to data quality 58 (93% female) were included in the analysis. Average age of participants was 17.8 (±6.9) years and body mass index was 15.5 (±1.9) kg/m2. Daytime average ENMO was 17.4 (±5.1) mg. Participants spent 862.6 (±66.2) min per day inactive, 88.4 (±22.6) min with light activities, 25.8 (±16.7) min with moderate activities and 0.5 (±1.8) min with vigorous activities. Participants slept for 461.0 (±68.4) min, waking up 1.45 (±1.25) times per night for 54.6 (±35.8) min, having an average sleep quality of 0.88 (±0.10). 31% of participants met sleep recommendations, with a significantly higher number of 6-13 year old patients failing to reach recommendations compared to 14-25 year old patients.

CONCLUSION

The patient group spent most of their time inactive at the beginning of treatment. Most patients failed to reach sleep recommendations. The use of raw data and opensource software should ensure result reproducibility, enable comparison across points in treatment and comparison with healthy individuals.

Sleep and mental disorders: A meta-analysis of polysomnographic research

Investigating sleep in mental disorders has the potential to reveal both disorder-specific and transdiagnostic psychophysiological mechanisms. This meta-analysis aimed at determining the polysomnographic (PSG) characteristics of several mental disorders. Relevant studies were searched through standard strategies. Controlled PSG studies evaluating sleep in affective, anxiety, eating, pervasive developmental, borderline and antisocial personality disorders, attention-deficit-hyperactivity disorder (ADHD), and schizophrenia were included. PSG variables of sleep continuity, depth, and architecture, as well as rapid-eye movement (REM) sleep were considered. Calculations were performed with the "Comprehensive Meta-Analysis" and "R" software. Using random effects modeling, for each disorder and each variable, a separate meta-analysis was conducted if at least 3 studies were available for calculation of effect sizes as standardized means (Hedges' g). Sources of variability, that is, sex, age, and mental disorders comorbidity, were evaluated in subgroup analyses. Sleep alterations were evidenced in all disorders, with the exception of ADHD and seasonal affective disorders. Sleep continuity problems were observed in most mental disorders. Sleep depth and REM pressure alterations were associated with affective, anxiety, autism and schizophrenia disorders. Comorbidity was associated with enhanced REM sleep pressure and more inhibition of sleep depth. No sleep parameter was exclusively altered in 1 condition; however, no 2 conditions shared the same PSG profile. Sleep continuity disturbances imply a transdiagnostic imbalance in the arousal system likely representing a basic dimension of mental health. Sleep depth and REM variables might play a key role in psychiatric comorbidity processes. Constellations of sleep alterations may define distinct disorders better than alterations in 1 single variable. (PsycINFO Database Record

Activity-based anorexia in C57/BL6 mice: effects of the phytocannabinoid, Delta9-tetrahydrocannabinol (THC) and the anandamide analogue, OMDM-2

The activity-based anorexia (ABA) paradigm is one of the few animal models of human anorexia nervosa. We present here the translation of this approach to C57/BL6 mice, a common background for genetically modified mice, and investigate the effects of the cannabinoid agonist, Delta(9)-tetrahydrocannabinol (THC) and the endocannabinoid uptake inhibitor, OMDM-2 in this model. The ABA paradigm was optimised so that food-restricted wheel-running mice displayed anorexia, reduced body weight and disrupted activity and circadian cycles. These conditions produced a murine ABA model with a defined stage and stability to allow for pharmacological intervention. Daily Delta(9)-THC (0.5 mg/kg) decreased survival in the ABA animals but increased feeding in the survivors, OMDM-2 (3 mg/kg) increased food intake, but not sufficiently to reverse weight loss. The effects of this model on endocannabinoid tone in the brain remain to be determined. Since the endocannabinoid system may be implicated in anorexia nervosa and in view of the positive modulation by cannabinoids of some aspects of ABA in this study, further investigation of the effects of cannabinoids in ABA is warranted.

Sleep in eating disorders

Sleep research on eating disorders has addressed two major questions: (1) the effects of chronic starvation in anorexia nervosa and of rapidly fluctuating eating patterns in bulimia nervosa on the sleep regulating processes and (2) the search for a significant neurobiological relationship between eating disorders and major depression. At present, the latter question appears to be resolved, since most of the available evidences clearly underline the notion that eating disorders (such as anorexia and bulimia nervosa) and affective disorders are two distinct entities. Regarding the effects of starvation on sleep regulation, recent research in healthy humans and in animals demonstrates that such a condition results in a fragmentation of sleep and a reduction of slow wave sleep. Although several peptides are supposed to be involved in these regulatory processes (i.e. CCK, orexin, leptin), their mode of action is still poorly understood. In opposite to these experimentally induced sleep disturbances are the findings that the sleep patterns in eating disorder patients per se do not markedly differ from those in healthy subjects. However, when focusing on the so-called restricting anorexics, who maintain their chronic underweight by strictly dieting, the expected effects of malnutrition on sleep can be ascertained. Furthermore, at least partial weight restoration results in a 'deepening' of nocturnal sleep in the anorexic patients. However, our knowledge about the neurobiological systems (as well as their circadian pattern of activity) that transmit the effects of starvation and of weight restoration on sleep is still limited and should be extended to metabolic signals mediating sleep.

Sleep variables in anorexia nervosa: evolution with weight restoration

OBJECTIVE

Studies on sleep patterns in anorexia nervosa (AN) have yielded inconsistent results. Therefore, we have studied the evolution of subjective and objective sleep characteristics in AN patients before and after weight restoration.

METHOD

Thirty-four severely underweight AN inpatients of the restrictive subtype had a polysomnographic sleep registration at the time of admission and after weight restoration. Subjective sleep quality was also measured with self-report instruments.

RESULTS

Objective sleep variables did not change with weight restoration, whereas subjective quality of sleep did improve. Percentage of underweight at admission and amount of slow wave sleep were predictors of the length of time required for weight restoration.

DISCUSSION

The finding that weight restoration does not affect polysomnographic sleep variables in AN patients seems to contradict previous studies.

Growth hormone-insulin-like growth factor-1 axis, leptin and sleep in anorexia nervosa patients

The present study characterizes the relationships between severe malnutrition, sleep, growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis, and leptin levels in anorexia nervosa (AN) patients before and after weight gain. Eleven restricting-type anorectic females (mean age = 19.7 years) with severe starvation state [mean body mass index (BMI) = 13.3] were studied using polysomnography and spectral power analysis. The hormone levels were measured in the morning after sleep recording. Eleven normal-weight, age- and gender-matched healthy volunteers without a history of any eating disorder served as controls. After nutritional treatment for about 2 months (65.7 +/- 6.4 days), sleep examinations and blood tests were repeated. At this stage, the study group consisted of 5 patients (mean BMI = 15.6). Higher IGF-1 and leptin levels were associated with longer and deeper sleep among anorectics. The sleep parameters including the percentages of stage 1 sleep and SWS as well as IGF-1 tended to normalize after only limited weight gain. Sleep disturbances in anorectics may be mediated through changes in the levels of the GH-IGF-1 axis hormones, as well as the levels of leptin.

All-night electroencephalographic sleep and cranial computed tomography in depression. A study of unipolar and bipolar patients

All-night electroencephalographic (EEG) sleep recording and cranial computed tomography were performed in 24 inpatients with major depression (14 unipolar, 10 bipolar). The patients showed the characteristic "depression-like" EEG sleep alterations and their ventricular brain ratio (VBR) was increased compared with the control subjects. No major differences were found between the unipolar and the bipolar groups. There was a close and positive association between the VBR values and several measures of slow wave sleep. It is hypothesized that this relationship is due to an altered function of the limbic-hypothalamic-pituitary-adrenocortical axis in depression that affects both EEG sleep and brain morphology.