To determine the most useful index of pubertal gonadotropin secretion we measured spontaneous LH and FSH levels every 20 min for 24 h and the LH and FSH responses to LHRH in a total of 37 girls and 30 boys representing each of the 5 stages of puberty. Mean 24-h LH and FSH levels rose significantly with increasing pubertal stage in both girls and boys. LH peak amplitude increased significantly with increasing pubertal stage for both sexes, whereas FSH peak amplitude did not. LH and FSH peaks were present throughout the 24-h period in all children, but the frequency did not change significantly with increasing pubertal stage. Mean gonadotropin levels, peak amplitudes, and peak frequencies tended to be higher at night from pubertal stages 1-4 of puberty. There were no significant sex differences in mean LH, LH peak amplitude, or LH peak frequency. The LHRH-stimulated peak LH to peak FSH ratio was greater in boys than girls during pubertal stages 1-3 and was less useful in distinguishing pubertal from prepubertal boys. For girls, the most accurate index of pubertal gonadotropin secretion was a LHRH-stimulated peak LH to peak FSH ratio greater than 0.66, which detected 96% of the pubertal girls with no false positives. For boys, the most accurate index was a maximum spontaneous nighttime LH level of 12 IU/L or more, which detected 90% of the pubertal boys with no false positives. We conclude that there are important sex differences in the gonadotropin responses to LHRH during puberty, and that criteria for the onset of pubertal gonadotropin secretion should be sex specific.

No abstract

Precocious puberty often leads to short adult height. Since the introduction of luteinizing hormone-releasing hormone (LHRH) agonist treatment for LHRH-dependent precocious hormone (LHRH) agonist treatment for LHRH-dependent precocious puberty in 1979, several reports have shown increased predicted height among LHRH agonist-treated children. To determine whether the LHRH agonist deslorelin can normalize the adult height of children with precocious puberty, we are conducting a long-term pilot study involving 161 children. This report describes the first 44 children to have attained final or proximate adult height. These children were 7.1 +/- 1.2 (mean +/- SD) yr old (bone age 11.8 +/- 1.5 yr) and had been in puberty for 3.1 +/- 0.3 yr at the start of treatment. They were treated with deslorelin (4 micrograms/kg/day sc) for 4.1 +/- 1.3 yr and had been withdrawn from treatment for an average of 2.4 yr at the time of this study (age 13.6 +/- 0.9 yr). Fourteen of the 44 children, who had grown less than 0.5 cm during the previous year, were considered to have attained adult height. The other 30 children had achieved 98.6% of predicted mature height (Bayley-Pinneau method) and were considered to be at proximate adult height. The final or proximate adult height of these 44 children averaged -1.1 SD compared to the adult height of the normal population. This height was significantly greater than the pretreatment height (-1.1 vs. -2.0 SD, P less than 0.01), but significantly less than both the predicted height at the end of treatment (-1.1 vs. -0.5 SD, P less than 0.01) and the target height derived from the mean height of the parents adjusted for the sex of the child (-1.1 vs. 0.1 SD, P less than 0.01). The observation that the Bayley-Pinneau height prediction at the end of treatment overestimated the actual adult height emphasizes the importance of using final height data to assess the ultimate impact of LHRH agonist treatment. It also indicates the need for caution when predicting the adult height of children who are still receiving treatment. We conclude that deslorelin has improved the adult height of these patients but has not fully restored height to the patients' genetic potential. We hypothesize that further improvement will be seen in patients who are treated with less delay and at a younger bone age.