37: The hypothalamo-pituitary-gonadal axis (HGPA) in children with precocious puberty

摘要

36 children with true precocious puberty (25 girls aged 2 to 8 years, and 11 boys aged 1 to 9 years) were studied. The study included plasma testosterone (T) or estradiol (E2) assay, LH and FSH measurement before and after LHRH (0.1 mg/m2), and determination of nycthemeral variations of plasma LH in 9 subjects, sleep being monitored by polygraphic recorder. In the girls a parallel increase of E2 and LH was observed, correlated to the clinical degree of sexual maturation. A sleep-induced rise of plasma LH was present in 3 girls at stage P3 and in 1 girl at stage P4, absent in a P2 girl. 2 boys exhibited a parallel increase of T, LH and FSH. In the 9 other boys a contrast was noted between pubertal levels of T (2.5 to 5.8 ng/ml) and prepubertal levels of LH and FSH after LHRH. In 4 of them T response to HCG (3 × 1500) was in the upper range of adult values. In 4 of them no sleep-induced peak of LH was detected. It appears that in precocious puberty of girls the whole maturation of the HGPA is similar to that of normal, while in boys the early increase of the testicular sensitivity to LH may be concomitant with an incomplete pubertal maturation of the hypothalamus.