Ghrelin Activation and Neuropeptide Y Elevation in Response to Medium Chain Triglyceride Administration in Anorexia Nervosa Patients

Background & Aims: Ghrelin, a peptide found in the stomach, increases appetite and fat-free mass while suppressing energy expenditure. Ghrelin requires modification by medium-chain triglycerides (MCTs) to exert its physiological effects. In this study, we investigated ghrelin activation and the resulting physiological changes following MCT administration.

Methods: Thirty participants were selected from among inpatients diagnosed with anorexia nervosa (AN). The patients were randomly divided into three groups by the MCT content of their nutritional supplement: (1) 'MCT high' (>6 g/day), (2) 'MCT moderate' (1-6 g/day), and (3) 'MCT low' (<1 g/day). Physical factors such as body weight and composition, as well as levels of nutrition-related serum factors such as acylated (active form) and desacyl (inactive form) ghrelin, leptin, growth hormone, insulin-like growth factor, and neuropeptide Y (NPY) were measured at weeks 0, 2, 4, and 6 of the treatment protocol.

Results: Significantly higher ghrelin activation was found in the 'MCT high' than in the 'MCT low' group (P < 0.05). The amount of consumed MCT had a curvilinear relationship with the active ghrelin level (P = 0.00). NPY levels in the 'MCT high' group were significantly more elevated than in the 'MCT low' group (P < 0.05). MCT administration did not significantly affect the remaining factors.

Conclusions: This study clearly demonstrated that MCT activates ghrelin and increases NPY, suggesting that nutritional supplementation with MCT may be effective for the treatment of AN patients in an emaciated state.