Ghrelin and eating disorders

Background Ghrelin is a potent hormone with central and peripheral action. This hormone plays an important role in the regulation of appetite, food intake, and energy balance. Studies have suggested that ghrelin is involved with eating disorders (ED), particularly bingeing and purging. Genetic variants have also been studied to explain changes in eating behavior. Methods We conducted a literature review; we searched PubMed, Scientific Electronic Library Online (SciELO), and LILACS databases using the keywords “eating disorder”, “ghrelin”, “polymorphism”, “anorexia nervosa”, “bulimia nervosa”, “binge eating disorder”, and their combinations. We found 319 articles. Thirty-nine articles met the inclusion criteria. Results High levels of ghrelin were found in patients with anorexia nervosa (AN), especially in the purging subtype (AN-P). There was also a positive correlation between fasting ghrelin level and frequency of episodes of bingeing/purging in bulimia nervosa (BN) and the frequency of bingeing in periodic binge eating disorder (BED). Some polymorphisms were associated with AN and BN. Conclusion Changes in ghrelin levels and its polymorphism may be involved in the pathogenesis of EDs; however, further studies should be conducted to clarify the associations.

背景 饥饿素（ghrelin）是一类兼具中枢与外周生物学活性的强效激素。该激素在食欲调控、食物摄入及能量平衡维持中发挥关键作用。已有研究提示，饥饿素与进食障碍（eating disorder, ED）存在密切关联，尤其与暴食及导泻行为相关。学界亦通过研究遗传变异来阐释进食行为的改变机制。
方法 本研究开展了系统文献综述：以“进食障碍”“饥饿素”“多态性”“神经性厌食症”“神经性贪食症”“暴食障碍”及其组合作为检索词，在PubMed、在线科学电子图书馆（Scientific Electronic Library Online, SciELO）及LILACS数据库中进行检索。最终共检索得到319篇文献，其中39篇符合纳入标准。
结果 神经性厌食症（anorexia nervosa, AN）患者体内饥饿素水平升高，尤以导泻亚型神经性厌食症（AN-P）为显著。在神经性贪食症（bulimia nervosa, BN）患者中，空腹饥饿素水平与暴食/导泻发作频率呈正相关；在周期性暴食障碍（periodic binge eating disorder, BED）患者中，空腹饥饿素水平亦与暴食发作频率呈正相关。部分遗传多态性与神经性厌食症及神经性贪食症存在关联。
结论 饥饿素水平异常及其遗传多态性可能参与进食障碍的发病机制，但仍需开展进一步研究以明确二者间的具体关联。