Elevated circulating acylated and total ghrelin concentrations along with reduced appetite scores in infants with failure to thrive.

Failure to thrive (FTT) is a term used to describe inadequate growth in infants. The immediate cause is undernutrition. Ghrelin is a potent orexigenic hormone that induces a positive energy balance and enhances appetite. There is no information regarding the possible role of ghrelin in infants with FTT. The aim of this study was 2-fold: 1) to examine circulating ghrelin levels in FTT infants, compared with those of normally growing infants; and 2) to evaluate appetitive behaviors in the two groups. Plasma acylated and total ghrelin concentrations were measured in nine FTT and five normally growing infants (age range, 9-18 mo). Appetite was assessed using three novel appetite measures. Both acylated and total ghrelin levels were significantly elevated in FTT infants compared with controls (p = 0.03 or less). Infants with FTT scored significantly lower than control infants on all appetite measures (p = 0.002 or less). Ghrelin levels were inversely related to appetite, weight velocity, weight/length z-scores, and weight z-score. These findings provide the first evidence that infants with FTT have higher circulating ghrelin concentrations but paradoxically lower appetite scores. Increased ghrelin secretion may reflect an adaptive mechanism attempting to increase appetite and preserve energy balance in response to poor nutritional state.