Insulin, but not ghrelin, in human milk is related to maternal BMI and infant gain in fat mass (623.16)

Abstract

Excess infant weight and fat gain incur risk of later obesity. We investigated whether insulin or the orexigenic hormone, ghrelin, in human milk (HM) differed by maternal BMI and whether these hormones associated with infant adipose deposition.26 normal weight (NW) and 23 overweight (OW) breastfeeding women provided fasted HM samples at 2‐wks (T1), 2‐mos (T2), and 4‐mos (T3) for analysis of insulin, ghrelin, and milk fat. Fasting maternal blood was collected at T3 for insulin and ghrelin. Infant body composition was measured (by PeaPodTM) at T1 and T3.OW mothers exhibited higher insulin (p=0.04) and lower ghrelin (p<0.01) at T3 (n=18). HM insulin was positively associated with maternal pre‐pregnancy BMI at T1 (n=38; p<0.05) and T3 (n=18; p<0.05). Neither HM fat nor ghrelin differed between groups. Controlling for sex, infants of OW mothers weighed more at birth and remained larger until 1 mo (p<0.05). Neither infant %body fat nor fat mass (FM) differed between groups at T1 or T3, but infants of OW mothers had more fat‐free mass at both time points (p<0.03). Infant gain in FM (from T1 to T3) did not differ between groups. HM fat at T3 and insulin at T2 were predictive of infant gain in FM per day (p<0.03, R2=0.18, n=30; p<0.01, R2=0.52, n=17).Differences between NW and OW mothers in circulating insulin, but not ghrelin were evident in HM. HM fat and insulin may play a role in early infant fat gain and contribute to later obesity risk.Grant Funding Source: Supported by NIH T32 DK007658‐21, 5K24DK083772; Thrasher Research Fund; University of Colorado CCTSI