Unstandardized meal does not affect plasma concentrations of leptin, acylated and des-acylated ghrelin in humans

Introduction Leptin and both forms of ghrelin (acylated and unacylated) are peptide hormones involved in appetite control and food intake regulation in humans. Ghrelin is known as the only fast-acting orexigenic hormone, playing a substantial role in meal initiation, while leptin is a mediator of long-term regulation of energy balance, suppressing food intake and thereby protecting against pathological weight gain. It has been thought that circulating ghrelin concentrations are elevated by fasting and suppressed following a meal, whereas leptin concentrations change in the opposite direction[1]. Most human clinical studies only examined these changes after a standardized meal and in carefully selected probes. Assessing total ghrelin without separate measurement of acylated and unacylated hormone together with using different assay methods may also contribute to discrepancies between the studies’ results [2;3].