Breastfeeding, IGF‐I, adiposity rebound and childhood obesity in the Danish SKOT cohort

Abstract

High IGF-I concentrations in infancy has been associated with later obesity but the interactions between diet, IGF-I and growth in early life are complex as it also include early programming of the IGF-I axis. The objective was to examine diet, IGF-I, and growth in a cohort of healthy term infants in the Danish SKOT cohort. 252 infants were included at age 9 mo and followed up at age 18 mo. Plasma IGF-I was measured at 9 mo and anthropometry at 9 and 18 mo. Infants not being breastfed at 9 mo of age (46%) had higher median IGF-I concentration than breastfed infants (51.6 vs. 44.2 ng/mL) and there was a strong negative dose response effect of daily number of breastfeeding's on IGF-I concentration. IGF-I was negatively associated with birth weight and positively with increase in weight, length and BMI between birth and 9 mo. Between 9 and 18 mo IGF-I was positively related to increase in length, but negatively to change in BMI. Although infants with high IGF-I at 9 mo thus became thinner during the following 9 mo we speculate that this could reflect an early adiposity rebound and thereby an increased risk of obesity later in life.