Longitudinal measures of ghrelin and leptin are associated with growth of Peruvian infants 6–14 months of age

Abstract

Ghrelin and leptin are hormonal regulators of energy balance and therefore may be related to growth during infancy. As part of a zinc intervention trial, we measured plasma ghrelin, leptin, weight, length, and energy intake 3 times at 3-month intervals (T1,T2,T3) among 105 breast-fed infants aged 6–8 months initially who were at risk of stunting (length-for-age Z-score, LAZ <-0.5). Children were randomly assigned to receive 3 mg additional zinc/d, either as a supplement or in a fortified food, or a placebo. Separate regression analyses were conducted to determine if changes in weight-for-age Z-score (WAZ) were predictive of hormone levels or vice versa, controlling for the respective initial values and infant sex. There was no effect of zinc treatment on hormone levels. Ghrelin levels at T2 and T3 were negatively associated with changes in WAZ during the previous time periods, and leptin levels were positively associated with changes in WAZ during the previous time periods (p<0.01). Females had significantly higher leptin levels than males at T2 and T3 (p<0.05), even after controlling for BMI. Hormone levels were not related to subsequent changes in WAZ, changes in LAZ, or daily energy intake at any time. In conclusion, zinc intake did not affect plasma leptin and ghrelin levels in this population. It appears that ghrelin and leptin levels may respond to prior weight gain in late infancy, although these hormones do not predict subsequent growth. Supported by Bill & Melinda Gates Foundation