Leptin in Human Milk and Child Body Mass Index: Results of the Ulm Birth Cohort Studies

Abstract

The objective of the study was to investigate the potential association of human milk leptin concentrations with child body mass index (BMI) and BMI trajectory patterns up to two years of age among children in the Ulm SPATZ Health Study. Leptin concentration was measured in skimmed human milk by ELISA (R&D System). Child BMI was determined at two to three days, three to four weeks, four to five months, one year, and two years of age. In SPATZ, leptin concentration at six weeks was inversely associated with child BMI at four to five weeks [beta –0.13, 95%CI –0.21;–0.05)] and at three to four months –0.12 –0.21;–0.03)]. Among infants of average BMI shortly after delivery, six week leptin was positively associated with greater increase in BMI from four to five weeks up to two years of age [0.16 (0.04;0.27)]. No associations were observed for six month leptin. Direction of association was the same in the Ulm Birth Cohort Study (UBCS), but statistically insignificant as the point estimate included the null effect value. Our results from SPATZ suggest human milk leptin may play a role in early infant growth. However, it is plausible that the lack of associations in UBCS suggest that these differences of human milk leptin composition between populations could have an impact in infant growth and development in a given population.

Potential sex differences in human milk leptin and their association with asthma and wheeze phenotypes: Results of the Ulm Birth Cohorts

“…However, these differences were not no longer visible following standardization. 8 Nonetheless, we cannot rule out the effect of differences in other exposures, which include but are not limited to differences in the genetic makeup in other human milk components between the two studies. Still, there is no clearly defined recommendation for what constitutes an adequate supply of leptin through human milk to ensure the most benefit for infants.…”

“…Child BMI measurements were also converted to z-scores based on the respective study population (UBCS or SPATZ) using separate linear models for each measurement period and adjusted for the precise age at assessment (days) and child's sex. 8 The derivation of child BMI z-scores was based on the relative study population rather than from standardized growth charts in order to ensure that the associations reported were reflective of the source population. 32 Logistic regression was used to assess associations between standardized leptin and wheeze phenotypes as well as doctor-diagnosed asthma.…”

“…3,4 Interest has spiked in human milk leptin, a hormone widely supposed to play a role in metabolic programming during early infancy. [5][6][7] Leptin in human milk has been studied extensively in relation to short-term regulation of food intake, infant growth, and adiposity [7][8][9] but also maternal adiposity. [10][11][12] However, emerging evidence suggests that circulating leptin also plays a potential role in the respiratory and immune systems.…”

Metabolic Hormone Profiles in Breast Milk From Mothers of Moderate-Late Preterm Infants Are Associated With Growth From Birth to 4 Months in a Sex-Specific Manner

“…Hence, together with the current available literature detailing conflicting associations between HM leptin and infant growth trajectories, our findings cannot secure any definitive conclusions around this linkage. As previous studies have already noted (51), accounting for the interactions that leptin has with other hormones, including glucocorticoids (52) and other metabolic hormones (53,54) might be necessary to fully understand the role of leptin in relation to infant growth trajectories. Additionally, taking into consideration the possibility that HM leptin may signal maternal nutritional and metabolic status and perhaps the food availability in the environment the infant will face after weaning might also be important in order to fully understand the programming role of this metabolic hormone.…”

Obesogenic Programming Effects during Lactation: A Narrative Review and Conceptual Model Focusing on Underlying Mechanisms and Promising Future Research Avenues

“…Insulin and leptin are actively transported from the mother to the infant through human milk more consistently from the beginning on [ 13 , 14 ]. Notably, while leptin concentrations in human milk were positively associated with lower child weight outcomes shortly after birth (i.e., first weeks to months) [ 15 , 16 ], positive associations of leptin with accelerated increases in child weight outcomes have been found later on [ 16 ]. Leptin is a well-known satiety hormone that suppresses appetite, which might explain why exogenous leptin from human milk may initially be associated with lower infant weight.…”