Associations Among Maternal Adiposity, Insulin, and Adipokines in Circulation and Human Milk

Background Insulin, leptin, and adiponectin regulate energy balance and may influence infant growth via their presence in human milk. Maternal body mass index has been associated with human milk insulin, leptin, and adiponectin concentrations, but results are inconsistent. Maternal serum hormone concentrations and fat mass may better characterize human phenotype and be more appropriate predictors of human milk insulin, leptin, and adiponectin. Research aim To examine the associations of human milk insulin, leptin, and adiponectin with their concentrations in maternal circulation and with maternal fat mass. Methods Insulin, leptin, and adiponectin were measured in serum and human milk at 1 month postpartum in 25 women. Total body fat mass and fat-free mass were measured using bioelectrical impedance analysis. Linear regression modeling was used to examine associations of serum hormone concentrations or fat mass with human milk insulin, leptin, and adiponectin after adjusting for covariates. Results Serum insulin (p= .007), leptin (p< .001), and adiponectin (p< .001) were each associated with their respective concentrations in human milk. Fat mass was positively associated with insulin (p= .005) and leptin (p< .001), but not with adiponectin (p= .65), in human milk. Conclusions Human milk insulin, leptin, and adiponectin were positively associated with their concentrations in serum, and human milk insulin and leptin were associated with maternal fat mass. Future research is needed to elucidate the role of human milk hormones in infant energy balance and growth.

Automated summary

The study showed that concentrations of insulin, leptin, and adiponectin in human milk were positively associated with their concentrations in maternal serum, and human milk insulin and leptin were associated with maternal fat mass, indicating the potential influence of maternal factors on human milk composition and its impact on infant growth.