Hormonal Changes in Puberty II. Correlation of Serum Luteinizing Hormone and Follicle Stimulating Hormone With Stages of Puberty and Bone Age in Normal Girls

Abstract

The concentration of serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) was determined using a double antibody radioimmunoassay in 129 normal girls. Of this group, 48 were prepubertal (PjJ and 81 girls were at varying stages of pubertal development from P 2 to P 5 . The mean serum LH concentration was similar in the prepubertal (Pj) and nonmenstruating girls (P2-4) (3.8-4.2 ng/ml) (table I, fig. 1). A difference was observed in the serum FSH levels that increased steadily from 1.70 ng/ml at P x to 3.4 ng/ml at stage P 3 of puberty. No further change in the concentration of serum FSH was seen in girls from P s to P 4 . The LH/FSH ratio was lower in girls at stage P 2 than in the prepubertal girls.In the menstruating girls (P 6 ), mean concentration of serum LH was within the same range (5.1-4.6 ng/ml) during the three phases of the menstrual cycle. Changes in the concentration of serum FSH was observed in menstruating girls: phase I (days 1-12), 3.99 ng/ml; phase II (days 13-18), 3.59 ng/ml; and phase III (days 19-30), 2.51 ng/ml.The relation of the serum LH and FSH levels and LH/FSH ratio to chronologic age was studied (table III). The concentration of LH was not significantly different in girls of 8-12 years. Serum FSH increased from 9 to 13 years. The LH/FSH ratio decreased at 9 years of age with no further change from 10 to 15 years. In addition, serum LH and FSH levels and LH/FSH ratio were compared with bone age (table IV). Serum LH was slightly but significantly less in girls with a bone age of 8 years than in those with a bone age of 6 years. A significant increase in FSH and LH levels was observed in girls with a bone age of 12 years compared with those with a bone age of 8 years.In 14 children with multiple pituitary hormone deficiencies, the serum LH concentration was 2.2 ng/ml and the serum FSH concentration was 1.5 ng/ml. In 12 patients with XO gonadal dysgenesis of pubertal age, the mean concentration of serum LH was 11.2 ng/ml and mean concentration of serum FSH was 54.5 ng/ml. In two patients with XO gonadal dysgenesis, aged 6.5 and 9 years, the serum LH values were 2-5 and 4.5 ng/ml, and the serum FSH values were 1.5 and 2.75 ng/ml, respectively.The serum values described are of relative not absolute significance. Although the results indicate that small amounts of gonadotropins are secreted prior to the onset of signs of puberty, it is important to emphasize the necessity of better defining the lower limits of sensitivity of the assays for serum samples. SIZONENKO, BURR, KAPLAN and GRUMBACH 37The detection of serum FSH and LH in prepubertal children suggests that the hypothalamic-pituitary gonadal axis is at a low level of activity and already operative at this stage of development. The precise time of initiation of cyclical secretion of LH and FSH (the FSH and LH ovulatory surge) in pubertal girls and its relation to maturational changes in the ovary is not known but it seems likely that the increase in estrogen secretion by the ovary as puberty advances acts as a positive fe...

Pituitary-Gonadal Relations in Female Children and Adolescents

“…The earliest hormonal event of female puberty, as in the male, appears to be increased FSH secretion, with increased LH levels being delayed until secondary sexual development is moderately advanced. This is in general agreement with the cross-sectional data of Jenner et al [6], Penny et al [7], Sizonenko et al [10], Yen and Vicic [18], and Yen et al [19]. However, Boyar et al [1] have recently described sleep-associated bursts of LH release as an early phenomenon of puberty, before wakinglevels of LH are increased; the sequence of these early hormonal events requires further study.…”

Responsivity of Pituitary Gonadotropes to Luteinizing Hormone-releasing Factor in Idiopathic Precocious Puberty, Precocious Thelarche, Precocious Adrenarche, and in Patients Treated with Medroxyprogesterone Acetate

“…In normal children, basal FSH levels rise dramatically between stages 1 and 2 of puberty in girls (38), in contrast to the greater LH rise during the same time period in boys (6). The rise in plasma estradiol which entrains is evidence of the importance of FSH in the initiation of ovarian steroid synthesis during early puberty.…”

Hormonal Changes in Puberty I. Correlation of Serum Luteinizing Hormone and Follicle Stimulating Hormone with Stages of Puberty, Testicular Size, and Bone Age in Normal Boys

“…The FSH assay was conducted in a similar manner and full details are given in the accompanying paper [46]. Human FSH, LER-869-2 [55] (1 ng, was equivalent to 1.79 mlU, 2nd IRP by immunoassay; 2,782 IU/mg 2nd IRP by bioassay) was used for iodination and standards.…”