The Influence of Appetite-Related Central and Gut Hormones in Modulating Binge Eating Behaviour in Obese and Overweight Healthy Subjects

Malaysia has increasing challenges in lifestyle related diseases, which is related to eating habits and disorders. According to the National Health & Morbidity Survey in 2011; it was reported the prevalence of obesity is 15.1% in 2011; or 2.5 million of the population,; an increase of 7/9% when compared to the 14% prevalence in 2006. Binge eating is a symptom described in various eating disorders. It is an under-diagnosed medical condition closely linked to higher body mass index (BMI) or obesity as well as personality psychopathology, psychiatric and psychological disturbances. Meta-analysis has demonstrated that extremely strict restriction in dietary calorie and fat intake is needed to achieve meaningful weight loss. Appetite and satiety are influenced by extremely complex central and gut-related hormonal systems which modulate the regulation of food intake Centrally acting hormones include Neuropeptide Y (NPY), agouti gene-related peptide, orexin which are appetite-stimulating, melanocortins and alpha-melanocortin-stimulating hormone which promote satiety.

Gut-related peptides include ghrelin secreted by the stomach and the duodenum has orexigenic (appetite stimulating) effect; leptin secreted by adipose tissue has anorexic (appetite inhibiting) effect, cholecystokinin, glucagon-like peptide-1 (GLP-1) secreted by the proximal gastrointestinal tract which has slight anorexic effect, and peptide YY (PYY).

Appetite and obesity have also been commonly related to stress and may influence binge-eating episodes. Previous studies have demonstrated that high stress hormone cortisol is associated with increased appetite and cravings, with preference for high carbohydrate content, thus leading to weight gain.

In the previous study performed by our group on 738 normal subjects who were staffs of the Ministry of Health, Putrajaya, we found a prevalence of 19% binge eating behaviour, 83% of whom were either obese or overweight.

GLP-1 analogue used for the treatment of type 2 diabetes and is also shown to produce and maintain weight loss. Liraglutide, which provides a supra physiological amount of GLP-1 may cause appetite inhibition thus may benefit in reducing binge eating. The aim of this study is to closely observe the extensive profile of neuropeptide Y, ghrelin, leptin and GLP-1, influenced by a standard meal in binge eaters in comparison to non-binge eating controls. In addition, we aim to determine the association between binging and the respective appetite-related hormones and also cortisol. Finally we will also be assessing the efficacy of novel hormonal treatment of Liraglutide in reducing binge eating.