Presented at the Neonatal Society 2013 Spring Meeting.

Andreas NJ, Parkinson JRC, Hyde MJ, Jeffries S, Xiong R, Fitz-Simon N, Modi N

1Section of Neonatal Medicine, Chelsea and Westminster campus, Imperial College London, UK

Background: Leptin plays a fundamental role in the development and subsequent control of key metabolic pathways. The aim of this study was to determine if there was a relationship between leptin concentration in breastmilk and key maternal characteristics.

Methods: This study was carried out under research ethics approval (REC: 12/LO/0203). Mothers were recruited to the study from the post-natal ward at Chelsea and Westminster Hospital. Breast milk samples (10ml) were collected seven days post-delivery from lactating mothers (n=37), with the aid of a breast pump. Timing of sample collection was standardised to the morning in order to reduce the influence of diurnal variations in breastmilk composition. Samples were stored at -20°C. 1ml of sample was sonicated using an ultrasound probe prior to analysis. Leptin was measured using commercially available leptin ELISA kit (Millipore, UK). Concentrations of leptin in breastmilk were correlated with maternal data (age, pre-pregnancy BMI, pre-pregnancy weight, duration of pregnancy, 28 week glucose tolerance test, weight and BMI at the time of sample collection). Linear regression was performed in SPSS 20.

Results: Correlation analysis revealed a significant association between leptin and both maternal weight at sample collection (r=0.4, R².15, p=0.015) (figure 1) and maternal BMI at sample collection (r: 0.34, R²=0.12, p=0.05). Linear regression analysis revealed the change in leptin per 1kg increase in maternal weight at sample collection was 0.003ng/ml (95% CI: 0.001-0.005). No association was observed between leptin and other maternal characteristics (age, pre-pregnancy BMI, pre-pregnancy weight, duration of pregnancy, 28 week glucose tolerance test).

Figure 1: Plot of maternal weight at sample collection (kg) and leptin concentration (ng/ml). Line of best fit (solid)
and 95% CI (hatched) are also shown.

Conclusion: These data indicate an association between foremilk leptin concentration with maternal weight and BMI, at the time of sample collection. Though the bioactivity of breastmilk leptin is unknown, we speculate that this may be part of a feedback mechanism serving to regulate infant milk intake.

Corresponding author: n.andreas11@imperial.ac.uk

References
1. Konstantinos M (2012) The complex interaction between obesity, metabolic syndrome and reproductive axis: A narrative review. Metabolism
2. Koo M et al. The effect of maternal BMI on the concentration of appetite regulating peptides in breast milk. Neonatal Society Autumn 2011.