Human milk hormone intake in the first month of life and physical growth outcomes in preterm infants.

Context. Human milk contains hormones that regulate metabolism. Extrauterine growth restriction remains common among preterm infants, but the effect of ingesting milk hormones on preterm infant growth is poorly understood. Objective. To quantify associations of longitudinal exposure to leptin, adiponectin, and insulin in milk with physical growth of preterm infants. Design/Methods. In 50 preterm neonates (median gestational age 29.4 weeks), we sampled maternal milk on day-of-life 7, 14, 21, and 28 and measured hormone levels in whole milk by ELISA. Milk leptin levels were available for a subset of 18 infants. We calculated milk hormone doses by multiplying the hormone level by the milk volume ingested on each day and estimated the area under the curve (AUC) to reflect longitudinal exposure. We analyzed associations of milk hormone exposure with growth outcomes in generalized estimated equations. Main Outcome Measures. Weight gain velocity and z-scores in weight, length, head circumference, and body...