NOCTURNAL RISE OF LEPTIN IN NORMAL PREPUBERTAL AND PUBERTAL CHILDREN AND IN PATIENTS WITH PERINATAL STALK-TRANSECTION SYNDROME

We studied 24-h profiles of circulating leptin levels using a sensitiv e and specific radioimmunoassay in healthy pre- (Tanner 1) and puberta l boys and girls (Tanner 3-4) as well as in a group of patients with p erinatal stalk-transection syndrome. Similar nyctohemeral rhythm in se rum leptin levels were found in prepubertal (MESOR: 2.34+/-0.2 ng/ml; amplitude 0.32+/-0.1 ng/ml) and pubertal boys (MESOR 2.2+/-0.2 ng/ml; amplitude 0.38+/-0.07 ng/ml). Likewise, no differences were found betw een prepubertal (MESOR 6.6+/-1.07 ng/ml; amplitude 1.67+/-0.4 ng/ml) a nd pubertal girls (MESOR 4.05+/-0.5 ng/ml; amplitude 0.95+/-0.2 ng/ml) . In contrast, higher MESOR (p<0.002) and amplitude values (p<0.005) m ere found in prepubertal and pubertal girls than in prepubertal and pu bertal boys. Finally a significant nyctohemeral rhythm in serum leptin levels was found in patients with perinatal stalk-transection syndrom e (MESOR: 9.3+/-2.3 ng/ml; amplitude 1.46+/-0.4 ng/ml). This data show s the existence of sexual dimorphism in the nyctohemeral rhythm in ser um leptin levels that are not influenced by the pubertal stage or by p ulsatile anterior pituitary hormone secretion.