Subjective and Objective Actigraphic Sleep Monitoring and Psychopathology in a Clinical Sample of Patients with Night Eating Syndrome, With and Without Binge Eating Behaviors

Introduction: Night Eating Syndrome (NES) is a phenomenon combining aspects of both sleeping disorders and Eating Disorders (EDs). To the best of our knowledge, few studies to date have examined NES among patients with EDs. None examined ED patients with and without NES in clinical settings by comparing their sleep disturbances using the new NES diagnostic criteria (1). This study aimed to compare subjective and objective sleep patterns and ED-related psychopathology among NES patients with and without binge eating (BE) behavior. Method: The sample included 71 women, ages 19-62, referred for assessment to a hospital Eating Disorders Clinic. Measures included self-report questionnaires, psychiatric evaluation and actigraph recording for one week. Participants were divided into three subgroups: those with NES without BE behavior (NES-only, n = 17), with both NES and BE behavior (NES-BE, n = 22), and with BE behavior without NES (BE-only, n = 32). Results: Regarding objective sleep monitoring, only one group difference emerged: significantly longer sleep duration for the NES-only group than the other groups. Subjectively, both NES-only and NES-BE groups described significantly more sleep disturbances than the BE-only group. Moreover, only one intergroup difference emerged in ED-related psychopathology: According to new NES diagnostic criteria, the NESonly and NES-BE groups reported significantly higher levels of NES symptoms than the BE-only group. Conclusions: Groups' similarities in sleeping disturbances and psychopathology level and differences between objective and subjective sleep disturbances raise the question of whether NES should be considered part of the BE-only subgroup, calling for further research. DOI : 10.14302/issn.2574-4518jsdr-14-554 Correspondence: Yael Latzer, DSc Faculty of Social Welfare and Health Sciences University of Haifa, Haifa, 31905, Israel Tel: +972-54-4736673. Fax: +972-4-8543533. Email: latzery@gmail.com

For the current study, we used all proposed criteria published in 2010 (1), which include: significantly increased food intake in the evening (Evening Hyperphagia) and/or at night time (night ingestion) of at least 25% of daily food intake; at least two episodes like this per week; and awareness and recall of evening and nocturnal eating episodes. In addition, the daily pattern is manifested by at least three of the following features: morning anorexia; a strong urge to eat between dinner and sleep onset and/or during the night; insomnia; a belief that one must eat in order to sleep; and depressed or worsening mood in the evening. This syndrome is associated with significant distress, is maintained for at least 3 months, and is not secondary to any other medical or psychiatric disorder. These new criteria currently represent the most updated instrument for diagnosing NES.
Although few significant studies have investigated the prevalence of NES, all reports show that the syndrome is common among individuals who are overweight and/or obese. In the general population, approximately 1.5% of adults are affected by NES (4,5), but among individuals seeking weight loss treatment, the syndrome is significantly more prevalent (e.g., 8.9% in an obesity clinic) (4,5). Among patients seeking treatment for EDs, such as bulimia nervosa (BN), binge eating disorders (BED), and AN, the prevalence rates for NES were 9%, 16%, and 0%, respectively (6). In a psychiatric population, the prevalence rate is 12.3% for NES (7).
In addition, these conditions may be differentiated by the nature of their binge episodes, concerns about weight, and loss of control over eating. During BE episodes, individuals with BED are more likely to consume a higher number of calories than individuals with NES and to report a greater sense of loss of control (11,(26)(27)(28)(29)(30). Individuals with NES report fewer concerns about their body weight or shape than those with BED (24,31) and fewer instances of compensatory behaviors.
The few prior studies that documented the similarities and differences of individuals with BN versus NES mostly examined patients seeking treatment for sleep disorders at a sleep laboratory (6,9,10). Two case studies from the late 1980s provided initial reports on the clinical and psychological characteristics of patients with BN who also suffer from NES (17,18
Participents rated each items to their experience on the

Objective and Subjective Sleep Measures
As seen in With regard to subjective sleep data, as seen on Table 2, the mean score on the MSQ self-report indicated a significant group difference (F=5.75, df=2,70, p < .005). Duncan post hoc test revealed that the BE-only group showed significantly lower subjective sleep pathology than the other two groups. Of the 10 items on the MSQ questionnaire, 3 items revealed significant group differences, as shown on Table 2: taking sleeping pills, waking up during the night, and restless sleep.

Block Multiple Linear Regressions
As seen in Table 3     However, these measurements cannot describe all disturbances; hence, further study in a sleep laboratory setting is necessary to understand similarities and differences in sleep-wake cycles between groups.