Cord blood leptin concentrations in relation to intrauterine growth

OBJECTIVE Leptin, a hormone that signals the amount of energy stores to the brain, has recently been shown to play a role in the regulation of several hypothalamic pituitary axes, including the growth hormone axis. To investi gate a potential association between cord blood leptin concentrations and i ntrauterine growth we measured leptin concentrations in the cord blood of s mall for gestational age (SGA), appropriate for gestational age (AGA) and l arge for gestational age (LGA) healthy newborns. PATIENTS AND MEASUREMENTS Cord blood leptin concentrations were evaluated i n 25 SGA,100 AGA, and 45 LGA, neonates, RESULTS Leptin was detectable in all newborns in concentrations comparable with those found in adults. Moreover, SGA newborns had lower leptin concent rations (3.70 +/- 1.81 mu g/l) than AGA (5.65 +/- 4.98 mu g/l) and LGA newb orns (11.99 +/- 7.06 mu g/l) (P< 0.01). Cord blood leptin concentrations were significantly associated with pondera l index, cord blood insulin concentrations, placental weight and maternal s erum leptin concentrations. Importantly, the association between cord blood leptin concentrations and intrauterine growth status persisted after adjus ting for adiposity, placental weight, maternal serum leptin concentrations and cord blood concentrations. CONCLUSIONS Cord blood leptin concentrations are independently associated w ith intrauterine growth. Future studies are needed to elucidate the underly ing mechanism and clarify the role of leptin in regulating growth and contr olling appetite in newborns.