Adult height in girls with idiopathic true precocious puberty

GnRH analogs are used to suppress pituitary-gonadal activity in children with true precocious puberty. The indications for therapy in this situation are not established, as some girls have a slow evolutive form, and the capacity of GnRH analogs to preserve the adult height has not been evaluated. This study analyzes the growth and adult heights of 2 groups of girls with idiopathic true precocious puberty, 1 with a predicted height of 155 cm or less (group 1, 19 cases) and the other with a predicted height of more than 155 cm (group 2, 15 cases). Group 1 patients were treated with a long-acting GnRH analog (D-Trp6-GnRH), and group 2 patients were followed without therapy. Group 1 showed greater clinical signs of estrogenization, vaginal maturation index (P < 0.03), plasma estradiol (P < 0.0004), and ratio of LH/FSH peaks (P < 0.01) at the initial evaluation than did group 2. The mean target heights were similar (difference, 0.9 cm). In group 1, the adult height (159 +/- 1.1 cm) was greater than the predicted height before therapy (152 +/- 1.4 cm; P < 0.0001). The difference between the adult height and the predicted height before therapy (mean, 6.5 cm) correlated positively with the bone age advance (P < 0.01), negatively with the predicted height (P < 0.05), and positively with the difference between the target and predicted heights (P < 0.001) before therapy. In group 2, the adult height (162 +/- 1.4 cm) was similar to the predicted height at the initial evaluation (162.5 +/- 1.4 cm). Adult heights correlated with target height in group 1 and with predicted height at the initial evaluation in group 2. In conclusion, some girls with true precocious puberty and poor adult height prediction who are treated with GnRH analog achieve an adult height more comparable to their target height. However, the lack of effect on height in girls with predicted height at the onset of therapy similar to their target height and preservation of the growth potential in the slow evolutive forms suggest that these forms might not require immediate therapy. Careful follow-up before therapy may be a better way of evaluating their natural course.

Growth response to growth hormone during the first year as a diagnosis criterion of growth hormone deficiency

Idiopathic growth hormone (GH) deficiency is a clinically and biologically heterogeneous condition. This study evaluates the capacity of the initial growth response to hGH therapy to distinguish certain from transient GH deficiency. Twenty-five patients having a GH peak < 10 micrograms/l after 2 pharmacological stimulation tests were classified according to the accuracy of the diagnosis of GH deficiency. Group 1 (n = 17) had certain GH deficiency because of pituitary stalk interruption syndrome and/or familial form. Group 2 (n = 8) had a transient GH deficiency. The mean increase in height standard deviation (SD) was 1.3 +/- 0.1 (mean +/- SE) and 0.5 +/- 0.1 during the first and second years in group 1 and 0.4 +/- 0.1 (p < 0.0005, compared to group 1) and 0.1 +/- 0.2 (p < 0.025 compared to group 1) during the first and second years in group 2. During the first year of therapy, the increase in height was > or = 1 SD in 14 patients of group 1 and in 1 patient of group 2. In group 1, this increase was positively correlated with an increase in body mass index (r = 0.80, p < 0.01) during the first year and with target height (r = 0.60, p < 0.02) during the second year. Growth rate (SD for age) during the first year in this group was negatively correlated with the height prior to therapy (r = -0.72, p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence of hypothalamic-pituitary thyroid abnormalities in children with end-stage renal disease

Patients with end-stage renal disease may have abnormalities of growth and of gonadal and thyroid hormones, so we attempted to determine the mechanisms that may be involved in the altered thyroid function. We evaluated serum thyroid hormone levels, their changes immediately after hemodialysis, the serum thyrotropin (thyroid-stimulating hormone (TSH) response to thyrotropin releasing hormone, and the circadian pattern of serum TSH in nine children with end-stage renal disease who were between 7 1/2 years and 17 years 1 month of age. Seven patients had been receiving hemodialysis for a median of 3.3 years; the other two were receiving continuous ambulatory peritoneal dialysis. Four patients had low serum total thyroxine (T4) values, and all nine had low free T4 values. Mean concentrations of total T4, free T4, and total triiodothyronine (T3), which were significantly less than normal before hemodialysis, returned to normal levels immediately after dialysis. Postdialysis thyroid hormone increases did not correlate with the decrease in weight or the increase in hematocrit observed immediately after dialysis. All but one patient had basal TSH levels within the normal range. Three patients had a deficient TSH response to thyrotropin releasing hormone, and the TSH response was prolonged in all of them. The mean (+/- SD) nocturnal TSH surge was 50 +/- 68%. Five of the eight patients studied had a nocturnal TSH surge below the normal range (95% confidence limits 47% to 300%). Serum free T4 values correlated with the TSH nocturnal surge (r, 0.73; p less than 0.05). Our findings support the hypothesis that some patients with end-stage renal disease have central hypothyroidism.