Searching food during the night: the role of video-polysomnography in the characterization of the night eating syndrome

Abstract

ObjectivesTo describe the video-polysomnographic (VPSG) features of the night eating syndrome (NES), exploring the existence of potential subtypes. MethodsIn this study, 20 consecutive patients with NES according to the most recent diagnostic criteria underwent an overnight VPSG. None of them presented with a sleep-related eating disorder (SRED). VPSG recordings were reviewed identifying all eating episodes. For each episode, eating latency (time delay from awakening to food intake), eating duration (time between eating onset to eating offset) and sleep latency after eating offset (time delay from eating offset to sleep) were calculated. Total episode duration was considered as the time between awakening and sleep latency after eating offset. ResultsTen patients fulfilled the A1 core criterion for NES (evening hyperphagia with consumption of at least 25% of the daily caloric intake after the evening meal); within this group, eight patients also fulfilled the A2 criterion (at least two episodes of nocturnal eating per week) and were thus included in the evening hyperphagia (EH) subgroup. The remaining 10 patients satisfied only the A2 core criterion for NES, constituting the nocturnal ingestion (NI) subgroup. We recorded 20 eating episodes, seven in the EH group and 13 in the NI group. In the EH subgroup, three eating episodes occurred before sleep onset, one after an awakening from non-rapid eye movement (NREM) stage 1 sleep, two from NREM stage 2 and one from REM sleep. All 13 NI episodes occurred after an awakening from sleep (1 from NREM stage 1 sleep, 8 from NREM stage 2 and four from NREM stage 3). In EH patients, eating latency, total episode duration and sleep latency after eating offset were significantly longer than in NI patients. ConclusionOur VPSG data from a case series of 20 patients referred to our center for nocturnal eating indicate potential different NES subtypes. This distinction may have an impact on patients’ treatment and follow-up.