Ghrelin activation and neuropeptide Y elevation in response to medium chain triglyceride administration in anorexia nervosa patients.

OBJECTIVE

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.