LH AND FSH RESPONSE TO LH-RH IN 27 GIRLS WITH PRECOCIOUS PUBERTY

Abstract

An LH-RH test was done in 27 girls with precocious puberty (PP), 26 idiopathic and one with a brain tumor, and in 47 girls with normal puberty (pubertal staging according to Tanner). In 10 girls with PP tested before the age of 8 at an early pubertal stage (P2) basal LH (0.58±0.22 mIU/ml) and peak LH (2.10±1.05 mIU/ml) were within the normal prepubertal range (basal LH 0.43±0.12, peak 3.03±0.3). However, basal FSH (1.71±0.79) and peak releasable FSH (9.26±5.98) were significantly higher than in pre-pubertal controls (basal FSH 0.6±0.2, peak 2.0±0.88). Peak FSH was also higher than peak values obtained from controls of the same pubertal stage (basal FSH 2.2±0.8, peak FSH 6.2±2.3). 17 girls were tested after age 8(8–11) in a later pubertal stage (P3). Basal LH (1.23±0.66) and peak releasable LH (15.05±6.2) were not only higher for chronological age but peak LH was higher than the values observed in normal girls with a later pubertal stage (P4 - basal LH 1.6±0.2, peak 13.5±1.97). Similar results were observed with plasma FSH in more advanced PP; basal FSH was 1.84±0.8 and the peak was 5.4±2.7, corresponding with the values of more advanced pubertal stages in normal girls (P4 - basal FSH 2.0±0.7, peak FSH 4.5±1.6). It is concluded that in central PP gonado-trophins are secreted by a pattern similar to that in normal puberty at an earlier age, but that the intensity of individual secretion is greater than in controls both for age and stage.