Intrauterine growth restriction (IUGR) is associated with increased leptin synthesis and binding capability in neonates

Abstract

Objective: Animal studies suggest pathological foetal programming of hypothalamic circuits regulating food intake in the setting of leptin deficiency and intrauterine growth restriction (IUGR). We aimed to compare placental leptin synthesis and leptin-binding capability in venous cord blood between IUGR newborns and neonates born appropriate for gestational age (AGA).

Design: Prospective controlled multicentre study.

Patients: Twenty-one ultrasound-proven IUGR and 33 AGA neonates.

Measurements: The concentration of leptin and soluble leptin receptor (sOB-R) in venous cord blood at birth was determined. Moreover, placental gene and protein expression of leptin and placental mRNA expression of functional and total leptin receptor isoforms were measured.

Results: Whereas log-leptin concentration in venous cord blood did not differ between IUGR and AGA newborns, the concentration of log-sOB-R was elevated in IUGR neonates (p(confounder adjusted)=0·009). Placental leptin protein synthesis as well as leptin mRNA was significantly higher in IUGR than in AGA infants (log-transformed, relative gene expression, p(confounder adjusted)=0·004). Analysis of gene expression of functional and total leptin receptor isoforms did not show any difference between both groups.

Conclusions: Leptin-binding capability in venous cord blood is increased in IUGR newborns. Thus, via foetal programming, reduced biologically active leptin levels might contribute to a perturbed regulation of appetite.