Age of thelarche and menarche in contemporary US females: a cross-sectional analysis.

AIM: A recent secular trend towards earlier thelarche has been suggested. The aim of this study is to examine normative ages of thelarche and menarche in contemporary US females. METHODS: Trained physicians documented Tanner breast stage by observation in a cross-sectional cohort. Age of menarche was self-reported. The subjects were healthy female children and adolescents. The mean age of thelarche was determined by probit analysis and the mean age of menarche was determined by using a normal time-to-event model. RESULTS: Mean age of thelarche was 9.7 years among 610 females aged 3.0-17.9 years (70% non-Hispanic Caucasian (NHC), 14% African-Americans, 7% Hispanic, 9% "other"). The mean age of menarche was 12.8 years for NHC, with African-Americans having menarche 0.6 years earlier. CONCLUSIONS: Thelarche occurred earlier than recently reported, while age of menarche remained unchanged, this supported a persistent secular trend towards earlier thelarche but stable age of menarche. This suggests that the observed thelarche is gonadotropin-independent or the tempo of pubertal advancement has slowed.

An overview of the GHMonitor, a registry of children treated with Saizen somatropin [recombinant hGH for injection].

The GHMonitor, introduced in 1998, monitors demographics and outcomes in children treated with Saizen (somatropin [recombinant hGH for injection]). Follow-up data are available on 697 patients. The proportion of male to female patients receiving growth hormone (GH) treatment was 67:33. Severity of the height deficit present at enrollment varied by diagnosis with patients with Turner syndrome being shortest [height standard deviation score (SDS)=-3.7+/-1.7] and those with organic GH deficiency the least severely stunted (height SDS=-1.9+/-1.5). Forty-eight patients (6.9%) discontinued participation in the registry. The most common reason for discontinuing GH was completion of growth; the second was family relocation. There were 53 adverse events reported in 33 patients in 1977 patient-years of followup. Most were self-limited but 13 were serious, and 5 resulted in discontinuation of treatment. Data from The GHMonitor provide a real world glimpse of current North American GH treatment practices.

Neonatal hypoglycemia in a growth hormone registry: incidence and pathogenesis.

OBJECTIVE: To examine the characteristics of infants with neonatal hypoglycemia treated with growth hormone (GH) in order to gain insights into factors aiding in the identification of and timely treatment of hypopituitary neonates. STUDY DESIGN: The National Cooperative Growth Study (NCGS) database was examined to identify infants with neonatal hypoglycemia started on GH by 6 months of age. 169 infants (100 males, 69 females) were found and their data analyzed for physical characteristics, the presence of other hormone deficits, and the diagnostic methods used. RESULTS: Mean +/- SD baseline length standard deviation score (SDS) was -1.5 +/- 1.8. 148/169 infants had hypopituitarism. Twelve had isolated GH deficiency (GHD). Nine had hypoglycemia without hypothalamic or pituitary pathology. Structural central nervous system (CNS) lesions and/or midline facial defects were present in 66/169. 55/100 males had micropenis. Although 158 infants had GHD, only 90 infants had it documented by stimulation testing (80) or a critical sample when hypoglycemic (10). Multiple hormone replacement therapy was necessary in 89% of the hypoglycemic infants. CONCLUSIONS: The great majority of these hypoglycemic infants had GHD, usually secondary to hypopituitarism. Over 1/3 had structural lesions of the hypothalamic-pituitary area or midline facial defects. Although lengths may be normal in these infants, physical features such as micropenis or cleft lip and/or palate should suggest pituitary dysfunction as the etiology of their hypoglycemia. A critical blood sample for GH taken during hypoglycemia is a quick and definitive diagnostic tool.

Screening girls with Turner syndrome: the National Cooperative Growth Study experience.

The National Cooperative Growth Study (NCGS) database was examined to determine whether the availability of expert guidelines affected the clinical management of 955 patients with Turner syndrome (TS). Although cardiac and renal evaluations increased in frequency after guideline publication, hearing screenings declined. Although girls with TS show significant cardiac, renal, and hearing problems, screening for these disorders remains inadequate.

Do growth hormone (GH) serial sampling, insulin-like growth factor-I (IGF-I) or auxological measurements have an advantage over GH stimulation testing in predicting the linear growth response to GH therapy?

OBJECTIVE: To compare the relative utility of GH secretion via pharmacological stimulation, overnight serial sampling, IGF-I levels and auxological variables as predictors of change in height standard deviation score (deltaHt SDS) during GH treatment. DESIGN: A multicentre observational study. PATIENTS: Prepubertal children (n = 825) with idiopathic growth failure who were subsequently treated with GH were divided into two groups, based on their maximum GH response to pharmacological stimulation testing: (1) idiopathic GH deficiency (IGHD), defined by a maximum GH response < 10 microg/l (n = 300); and (2) idiopathic short stature (ISS), with a maximum GH response > or = 10 microg/l (n = 525) (GH conversion factor: 3 IU = 1 mg). MEASUREMENTS: Overnight spontaneous GH secretion was measured in all patients. The following characteristics of spontaneous GH secretion were studied: maximum or peak GH, mean peak GH, number of GH peaks, pooled GH, mean GH, and approximate entropy of GH secretion. RESULTS: Although children with IGHD had lower indices of spontaneous GH secretion, there were no differences between IGHD and ISS groups in baseline Ht SDS, growth rate or IGF-I level. The dose and duration of GH therapy were similar. There was no statistically significant difference in the mean (+/- SD) change in Ht SDS (deltaHt SDS) in the two groups (IGHD 1.3 +/- 0.9 and ISS 1.2 +/- 0.8). Measures of spontaneous secretion, such as peak GH, mean of GH peaks, mean area under GH peaks, and mean GH, as well as IGF-I concentrations, were all statistically significantly correlated with deltaHt SDS in IGHD children (P < 0.0001). A significant correlation was also observed for pooled GH (P = 0.002) and approximate entropy (P = 0.01). Children with the most severe ISS (Ht SDS < -3.33) demonstrated a more disorganized pattern of GH secretion compared to children who were not as short (Ht SDS -2.33 to -1.64), as indicated by a higher approximate entropy (0.673 +/- 0.193 vs. 0.607 +/- 0.161, P < 0.004). This increased disorder in GH secretion was accompanied by lower IGF-I levels (104 +/- 99 microg/l vs. 137 +/- 74 microg/l, P < 0.001), even though pooled GH concentrations were indistinguishable between the two groups (2.2 +/- 1.3 microg/l vs. 2.0 +/- 1.0 microg/l). Children with IGHD demonstrated lower approximate entropy than did those with ISS (0.551 +/- 0.235 vs. 0.631 +/- 0.182, P < 0.0001). Duration of GH treatment, height deficit and genetic potential (midparental Ht SDS) were the most important variables influencing deltaHt SDS in children receiving GH therapy. Maximum stimulated GH, IGF-I and indices of spontaneous GH secretion also correlated with deltaHt SDS, but their relative importance varied among diagnostic groups. CONCLUSIONS: Patients with GH deficiency demonstrate a reduced capacity for GH secretion, while those with idiopathic short stature exhibit a more disorderly and less functional secretory pattern. Although effective in predicting a response to GH treatment in patients with severe GH deficiency, overnight serial sampling is less practical than other methods currently available. In addition, serial sampling was less useful as a predictor of growth response to exogenous GH in patients with idiopathic short stature.

Use of magnetic resonance imaging in short stature: data from National Cooperative Growth Study (NCGS) Substudy 8.

The primary use of magnetic resonance imaging (MRI) in the evaluation of children with short stature (SS) is to discover lesions in the central nervous system (CNS), particularly tumors that may require intervention. MRI has a secondary role in identifying structural abnormalities responsible for growth hormone deficiency (GHD). We examined data from the National Cooperative Growth Study (NCGS) Substudy 8 to determine how American physicians are using MRI in evaluating children with SS. Of the 21,738 short children enrolled in NCGS, 5% underwent MRI during their follow-up. Children who had GH stimulation testing were more likely to have had an MRI than those in whom no GH stimulation test was performed (19% vs 2%, p <0.0001). Moreover, children diagnosed with severe GHD (maximum GH <5 ng/ml) were more likely to have an abnormal finding on MRI. Of these patients, 27% demonstrated an abnormality as compared to 12% and 12.5% in patients with partial GHD and normal GH stimulation test results (>10 ng/ml), respectively. Abnormalities unrelated to the hypothalamus or pituitary represented 30% of these findings, while disorders in pituitary anatomy, including pituitary hypoplasia, pituitary stalk interruption, and ectopic posterior pituitary, represented an additional 30% of abnormal MRI examinations. CNS tumors comprised 23% of abnormal findings in these patients. We conclude that MRI provides significant value in the evaluation of children with SS, by identifying CNS tumors associated with growth failure as well as anatomical abnormalities of the pituitary. These findings are useful in confirming the diagnosis of GHD in children and identifying potential candidates for continued GH replacement in adulthood.

Septo-optic dysplasia/optic nerve hypoplasia: data from the National Cooperative Growth Study (NCGS).

We analyzed data from 65 children with septo-optic dysplasia (SOD) referred for evaluation and followed in the National Cooperative Growth Study (NCGS) Substudy 8 and from 758 children treated with growth hormone (GH) and followed in the NCGS core study. Compared to other children referred for evaluation of short stature, children with SOD were younger (mean age 3.7 +/- 3.6 vs 8.6 +/- 4.9 years), had less severe short stature (mean +/- SD height SDS -1.80 +/- 1.64 vs -2.17 +/- 0.95), and were more likely to be female (46% F vs 31% M). Children with SOD who received GH were older and shorter than those referred and untreated, but the gender distribution was similar. Other pituitary hormone deficits were reported in untreated patients, including thyroid hormone deficiencies (8%) and adrenocorticotropic hormone (ACTH) deficiency (3%), as compared to 27% and 24%, respectively, in GH-treated children. Data on adult height were available for 71 patients, who showed an average gain in height SDS of 1.17 +/- 1.49. GH therapy was well tolerated in children with SOD.

A long-acting human growth hormone (Nutropin Depot): efficacy and safety following two years of treatment in children with growth hormone deficiency.

BACKGROUND: Nutropin Depots [somatropin (rDNA origin) for injectable suspension] is a long-acting form of human growth hormone (GH) to be administered by subcutaneous (s.c.) injection. The availability of this formulation offers the opportunity for greater convenience and compliance by decreasing the number of injections and frequency of administration required. OBJECTIVE: To determine the efficacy and safety of a long-acting formulation of GH administered in children with GH deficiency (GHD) once or twice monthly for 2 years. PATIENTS: Fifty-six previously untreated, prepubertal children with GHD received Nutropin Depot 1.5 mg/kg once monthly (1x/mo), or 0.75 mg/kg twice monthly (2x/mo) for 24 months. The mean pretreatment growth rate was 5.0 +/- 2.4 cm/yr. RESULTS: The 0-12 mo growth rate (mean +/- SD) was 8.3 +/- 1.5 cm/yr in the 1x/mo group and 8.2 +/- 2.0 cm/yr in the 2x/mo group. The 12-24 month growth rate was 7.2 +/- 1.5 cm/yr in the 1x/mo group and 6.9 +/- 1.5 cm/yr in the 2x/mo group. During the 24 months of treatment, height standard deviation score (SDS) increased by 1.0 +/- 0.5 SD in the two groups combined (p <0.0001). The corresponding advancement in bone age was 2.2 +/- 0.7 yr, resulting in a gain in Bayley-Pinneau predicted adult height (PAH) SDS of 0.6 +/- 0.9 SD in the 1x/mo group and 0.6 +/- 1.0 SD in the 2x/mo group. No serious adverse events attributable to the study drug were reported. Injection site reactions were common, but resolved without intervention. Pre-dose fasting and postprandial glucose and insulin levels, as well as hemoglobin A1c levels, were unchanged from baseline values. CONCLUSIONS: Treatment with Nutropin Depot is associated with catch-up growth and normal skeletal maturation and is a viable alternative to daily injections of GH in children with GHD.