夜间进食综合征的研究进展

Overview on Research of Night Eating Syndrome

夜间进食综合征(夜食症)是一种表现为早晨没有食欲、晚饭后过量进食或夜间醒来进食的进食障碍,并且与睡眠问题相关。在对国内外文献进行分析研究的基础上,本文先后介绍了夜食症的概念、发病的神经生理机制及主要的干预措施和治疗手段,并对现有研究的不足进行总结,提出了未来研究的方向,旨在为研究者在此领域的进一步探索提供参考。

Night eating syndrome(NES) is characterized by morning loss of appetite, evening hyperphagia or nocturnal awakening to eat, and is associated with sleep problems. NES has been described as a unique combination of an eating disorder, a sleep disorder and a mood disorder which is now included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition(DSM-V) as an Other Specified Feeding or Eating Disorder. With the development of the national economy, the pace of life of Chinese is becoming quicker and quicker. However, the growing pressure of life and competition may result in an unhealthy lifestyle, which might further lead to an irregular diet. It is estimated that the prevalence of NES is approximately 1.5% in the general population and is even up to 50% in selected clinical populations with obesity and diabetes. The prevalence is also high among patients with various psychiatric disorders(12~35%). According to studies available, NES is associated with life stress, psychoneurotocism, low mood, and adverse reactions to weight loss and its comorbidities include eating disorders, overweight and obesity, sleep disorders, depression, anxiety, and substance abuse. Therefore, NES is of importance clinically, of which development and maintenance is likely to be influenced by physiological, psychological, and social factors. Although the disorder has gained a great deal of attention in recent years, neural mechanisms of NES remain understudied in contrast to other eating disorders. Stunkard et al.(2009) proposed a biobehavioral model for NES, which was based on the function of the serotonin system and supported by a one single photon emission computed tomography(SPECT) study. It predicted that the interaction of stress and genetic vulnerability might elevate the serotonin transporters(SERT) levels in the midbrain, leading circadian delay and decreased satiety through the serotonin system. Notably, the role of prefrontal and limbic system dysregulation in the development and maintenance of NES was plausible. The model suggested that the decrease of cognitive and behavioral self-regulation could be produced by the prefrontal and limbic brain, which could further increase reward sensitivity to palatable food in the evening and night in persons with NES. To sum up, this study summarized neural physiological mechanisms of NES and discussed inadequacies of these models. Additionally, the review of the literature on the treatment of NES in the last 10 years shows a variety of strategies including pharmacologic treatments such as sertraline and other SSRIs, topiramate, agomelatine, psychological treatments such as cognitive behavior therapy(CBT), progressive muscle relaxation(PMR), and several other treatment alternatives such as phototherapy(PT), exercise and lifestyle interventions. However, the treatment of the syndrome is still in its infancy. For instance, the long-term therapeutic effects and internal mechanism of topiramate and agomelatine have not been determined and justify further studies involving these substances and similar medications. To conclude, future research should focus on the following aspects:(a) To explore the diagnosis of NES and enrich its measurement,(b) To further explore the pathogenesis of NES,(c) To develop the treatment of NES, including alternative pharmacological and combination therapies(pharmacological, phototherapy, weight loss and dietary, and psychological interventions),(d) To increase localization studies in China.