The pattern of gonadotropin and estradiol secretion in exaggerated thelarche.
OBJECTIVE
To assess the dynamics of the pituitary-ovarian axis in exaggerated thelarche, defined as premature thelarche associated with signs of systemic estrogen effects (advanced bone age and/or growth acceleration) without progression to complete puberty.


METHODS
Seven girls (age < 2.5 years) with exaggerated thelarche, 6 girls with inactive pituitary-ovarian axis (premature adrenarche) and 21 girls with activated axis (central precocious puberty) had serum FSH, LH and E2 measured serially before and 1 to 24 h after gonadotropin-releasing hormone agonist (GnRHa) administration (leuprolide, 20 micrograms/kg sc), used as a test of combined pituitary-ovarian stimulation.


RESULTS
Although girls in the exaggerated thelarche and adrenarche group had similar [mean (SEM)] baseline FSH [3.2 (0.9) vs 1.4 (0.3) IU/l], LH [0.36 (0.1) vs 0.27 (0.02) IU/l] and E2 [20 (1.2) vs 21 (2) pmol/l] concentrations, and similar peak post-GnRHa LH concentrations [5.5 (1.1) vs 2.4 (0.5) IU/l], girls with exaggerated thelarche achieved higher peak FSH [41 (9) vs 14 (3) IU/l, p < 0.01] and E2 [243 (40) vs 37 (6) pmol/l, p < 0.001] concentrations after GnRHa. In comparison to patients with exaggerated thelarche, girls with precocious puberty had higher (p < 0.01-0.001) baseline LH [3.6 (0.8) IU/l], baseline E2 [69(11) pmol/l], GnRHa-stimulated peak LH [68 (17) IU/l] and peak E2 [648 (58) pmol/l] concentrations, but similar FSH parameters.


CONCLUSIONS
Girls with exaggerated thelarche exhibit substantial E2 secretory potential that can be demonstrated by GnRHa stimulation, is predominantly FSH-driven, and probably accounts for the manifestations of estrogen effect seen in these girls.
Garibaldi
L R
LR
Department of Pediatrics, St Louis University, MO.
Aceto
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T
Weber
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D000704:Analysis of Variance; D001846:Bone Development; D001940:Breast / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D003687:Dehydroepiandrosterone / Q000031:analogs & derivatives / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006065:Gonadotropins, Pituitary / Q000378:metabolism*; D006801:Humans; D007223:Infant; D016729:Leuprolide / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood; D010902:Pituitary Gland / Q000378:metabolism; D011629:Puberty, Precocious / Q000097:blood* / Q000188:drug therapy
D006065:Gonadotropins, Pituitary; D003687:Dehydroepiandrosterone; D004958:Estradiol; D019314:Dehydroepiandrosterone Sulfate; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D016729:Leuprolide