Combined use of growth hormone and gonadotropin-releasing hormone analogues: the national cooperative growth study experience.

Gonadotropin-releasing hormone ana-logues (GnRHa) are used to treat central precocious puberty. They also are used to delay puberty in short children with a prognosis for impaired adult height. In both cases, growth hormone (GH) treatment is sometimes added. To determine how North American pediatric endocrinologists are using the combination of GH and GnRHa, we searched the National Cooperative Growth Study (NCGS) database and identified 509 patients who were treated with both. Among them were 139 patients with a diagnosis of precocious puberty. Most of these (82%) also had GH deficiency (GHD). Of the 370 patients who did not have precocious puberty, 71% had GHD. There were 200 patients with precocious puberty who were treated with GH but not with GnRHa. The children who were given GH alone (77% of whom had GHD) were much younger than the children who were given both GH and GnRHa (5.7 +/- 2.9 years for those who were not treated with GnRHa vs 9.1 +/- 2.7 years for those who were). Data on both predicted adult height before GH treatment and near- adult height were available for 141 of the patients who were given both GH and GnRHa. There was a statistically significant increase in near-adult height over pre-GH predicted adult height in girls with precocious puberty (5.4 +/- 4.3 cm) and without precocious puberty (3.0 +/- 6.1 cm). There was no statistically significant gain in height for boys who did not have precocious puberty (1.3 +/- 6.8 cm). There were too few boys with precocious puberty (n = 7) to enable meaningful conclusions. In a multiple regression analysis of data on girls who did not have precocious puberty, duration of GH treatment was the most important variable predictive of height gain.gonadotropin-releasing hormone, growth hormone, precocious puberty, idiopathic growth hormone deficiency, organic growth deficiency, idiopathic short stature.

Growth hormone stimulation test results as predictors of recombinant human growth hormone treatment outcomes: preliminary analysis of the national cooperative growth study database.

Growth hormone (GH) stimulation tests are considered a prerequisite to clinical trials of recombinant human GH (rhGH) therapy, but the test results may not be predictive of the treatment outcomes with rhGH. We examined the GH stimulation test results as a predictor of the treatment outcome in a cohort of prepubertal subjects in the National Cooperative Growth Study. A standard is proposed in which a diagnosis of GH deficiency is considered appropriate when a patient has significant first-year catch-up growth and that a positive stimulation test result predicts this outcome. With this construct, a traditional interpretation of GH stimulation test results correctly identifies 64% of the rhGH treatment outcomes. The analysis shows an upper limit of diagnostic sensitivity of 82% and a lower limit of specificity of 25% in our study population. The results of our recent studies suggest that the sensitivity and specificity of the current GH stimulation tests are attributable in part to broad intersubject variation in GH clearance, rates of GH elimination, and GH volume of distribution. The combined studies suggest that the use of subject-specific pharmacokinetic parameters will improve the diagnostic interpretation of GH stimulation test results and improve rhGH treatment outcomes.growth hormone stimulation tests, recombinant human growth hormone, pharmacokinetic parameters, maximal stimulated growth hormone concentration.

Patterns of medical practice in cystic fibrosis: part I. Evaluation and monitoring of health status of patients. Investigators and Coordinators of the Epidemiologic Study of Cystic Fibrosis.

This report characterizes patterns of evaluation and monitoring of the health status of patients with cystic fibrosis (CF) as observed in the Epidemiologic Study of Cystic Fibrosis (ESCF), and compares these practices to published guidelines. All patients (18,411) who enrolled in ESCF at 194 study sites in the United States and Canada from December 1, 1993 to December 31, 1995 were considered for study. Patients enrolled before January 1, 1995 with >/=1 healthcare encounters during 1995 (12,631) were included in the analysis. Patients enrolled after January 1, 1995 (5,266), or who died (354), withdrew from the study (128), or were lost to follow-up (21) were excluded. Frequency of encounters (outpatient and hospital), spirometry, respiratory tract cultures, and chest radiographs were recorded during a 1-year period (1995) and analyzed by gender, age, severity of lung disease, and presence of any Pseudomonas species in the respiratory tract. The 12,631 patients had 53,024 outpatient visits. In 57.5% of patients, the recommended criteria of >/=4 total visits per year were met. Only 27.4% of all patients had >/=4 routine visits; 3.1% had only sick visits, and 59.0% had no sick visits. One third (34.6%) were hospitalized at least once, for a total of 8,561 hospitalizations. Older patients with lower pulmonary function and Pseudomonas in their respiratory tract had fewer routine visits and more sick visits, and were hospitalized more than were younger patients. In three fourths (75.8%) of patients the recommended criterion of two spirometry assessments per year was met, whereas in 79.3% the criterion of one culture was met, and in 68.3% the criterion of one radiograph/year was met. We conclude that in the majority of CF patients, the recommended criteria for routine evaluation and monitoring were met. However, in a rather substantial number they were not. An increase in the utilization of healthcare resources was observed in patients with more severe disease. This information will help to establish benchmarks for future quality assessment programs.

Patterns of medical practice in cystic fibrosis: part II. Use of therapies. Investigators and Coordinators of the Epidemiologic Study of Cystic Fibrosis.

This report describes the prescribing pattern of therapeutic interventions in the management of patients with cystic fibrosis (CF), as observed in the Epidemiologic Study of Cystic Fibrosis (ESCF). Use of 20 therapies by 12,622 patients was recorded from each health care encounter (53,024 outpatient visits and 8,561 hospitalizations) during a 1-year period (1995), and analyzed by gender, age, severity of lung disease, and presence of any Pseudomonas species in the respiratory tract. The percentage of patients using the following pulmonary therapies was observed (in descending order): airway clearance techniques (88.2%); inhaled bronchodilators (82.2%); oral antibiotics (excluding quinolones) (68. 2%); dornase alfa (52.9%); intravenous antibiotics (34.4%); oral quinolones (34.4%); inhaled antibiotics (34.3%); mast cell stabilizers (29.5%); inhaled corticosteroids (25.9%); oral corticosteroids (17.1%); oral bronchodilators (16.2%); oxygen (8. 1%); inhaled mucolytic agent acetyl cysteine (6.5%); and diuretics (1.4%). The percentage of patients using nutritional therapies was: pancreatic enzymes (96%); oral nutritional supplements (31.1%); enteral nutrition (7.3%); and parenteral nutrition (0.7%). The percentage of patients using other therapies was: nonsteroidal anti-inflammatory drugs (7.9%); and insulin or oral hypoglycemic agents (6.1%). The general trend was for therapies to be used more by older patients, those with lower pulmonary function, and by those with Pseudomonas in their respiratory tract. Exceptions to this trend occurred for airway clearance, oral antibiotics, mast cell stabilizers, and pancreatic enzymes. Four therapies (oral nutritional supplements, parenteral nutrition, diuretics, and pancreatic enzymes) were used more by males than females. However, there was no gender difference for this group of therapies on pulmonary or nutritional status.

Response to growth hormone in attention deficit hyperactivity disorder: effects of methylphenidate and pemoline therapy.

OBJECTIVE: To determine whether treatment of attention deficit hyperactivity disorder (ADHD) with methylphenidate hydrochloride or pemoline diminishes the response to growth hormone (GH) therapy in patients with idiopathic GH deficiency (IGHD) or idiopathic short stature (ISS). METHODS: The National Cooperative Growth Study database was used to identify patients between 3 and 20 years of age with IGHD or ISS and those within these groups who were treated with methylphenidate or pemoline for ADHD. Their growth in response to GH treatment (change in height standard deviation score [SDS]) was compared with that of patients with IGHD or ISS who were not treated for ADHD, by using a stepwise multiple regression analysis. RESULTS: In the IGHD cohort, there were 184 patients who were being treated for ADHD and 2313 who were not. In the ISS cohort there were 117 patients who were being treated for ADHD and 1283 who were not. There was a higher percentage of males being treated for ADHD in both cohorts. In the IGHD cohort, the change in height SDS was positively associated with the number of years of GH treatment, parents' heights, body mass index, and GH injection schedule, and was negatively associated with height SDS at the initiation of GH therapy, age, and maximum stimulated GH level. The use of methylphenidate or pemoline had a negative effect on the change in height SDS, but the magnitude of the effect was small. Similar effects were noted in the ISS cohort, but body mass index and the use of methylphenidate or pemoline had no effect on the change in height SDS. CONCLUSIONS: Concurrent ADHD therapy is associated with a slight decrease in the change in height SDS during GH treatment in patients with IGHD but not in those with ISS. Even in IGHD, the magnitude of the effect is small and should not deter the use of such concurrent therapy.

Adult height in children with growth hormone deficiency who are treated with biosynthetic growth hormone: the National Cooperative Growth Study experience.

OBJECTIVE: To determine whether the height gain during puberty in children with growth hormone deficiency (GHD) who are treated with biosynthetic growth hormone (GH) is similar to that in otherwise healthy children with delayed bone ages and whether the height standard deviation score (SDS), which began to increase before puberty, continues to increase during puberty. METHODS: The inclusion criteria included a diagnosis of idiopathic GHD, prepubertal on enrollment in the National Cooperative Growth Study, and spontaneous onset of puberty, as defined by Tanner stage 2 breast development in girls and a testicular volume of at least 3 mL in boys. Near-adult height was judged to have been attained in the subjects who had reached a chronologic age of at least 18 years (females) or 20 years (males) or had reached at least pubertal stage 4 and a chronologic age of at least 14 years (females) or 16 years (males). These subjects constituted group 1. Group 2 was a subgroup of these subjects who met a more stringent criterion for near-adult height; in addition to meeting the above criteria, they had to have attained a bone age of at least 14 years (females) or 16 years (males). RESULTS: Group 1 consisted of 480 males and 194 females. Group 2 consisted of 153 males and 105 females. In the subjects in group 1, the Tanner pubertal stage 2 was 14.1 +/- 1.5 years in males and 12.6 +/- 1.6 years in females; the bone age at this stage was 11. 9 +/- 1.5 years in males and 10.6 +/- 1.5 years in females; and the height SDS was -2.1 +/- 0.9 in males and -2.4 +/- 0.9 in females. The total height gained during puberty was 22.4 +/- 7.9 cm in males and 17.4 +/- 6.3 cm in females; the percentage of adult height gained during puberty was 13.3% +/- 4.6% in males and 11.3% +/- 4.0% in females; the near-adult height SDS was -1.3 +/- 1.0 in males and -1.6 +/- 0.9 in females; and the target adult height SDS was -0.4 +/- 0.8 in males and -0.5 +/- 0.7 in females. The growth characteristics in the subjects in group 2 were of similar magnitude. In both groups, there was a significant negative correlation between age at the onset of Tanner stage 2 and both the total height gained during puberty and the percentage of adult height gained. CONCLUSIONS: The growth characteristics of these subjects were similar to those reported in normal children and in previous reports of the pubertal growth in smaller populations of children with GHD. The height SDS increased in these subjects during puberty, but the target adult height SDS was not attained. This is a strong argument for early diagnosis and treatment in children with GHD to optimize prepubertal growth.

Treatment of glucocorticoid-induced growth suppression with growth hormone. National Cooperative Growth Study.

Growth failure is common during long term treatment with glucocorticoids (GC) due to blunting of GH release, insulin-like growth factor I (IGF-I) bioactivity, and collagen synthesis. These effects could theoretically be reversed with GH therapy. The National Cooperative Growth Study database (n = 22,005) was searched for children meeting the following criteria: 1) pharmacological treatment with GC and GH for more than 12 months, 2) known type and dose of GC, and 3) height measurements for more than 12 months. A total of 83 patients were identified. Monitoring of glucose, insulin, IGF-I, IGF-binding protein-3, type 1 procollagen, osteocalcin, and glycosylated hemoglobin levels was performed in a subset of patients. Stimulated endogenous GH levels were less than 10 microg/L in 51% of patients and less than 7 microg/L in 37% of patients. The mean GC dose, expressed as prednisone equivalents, was 0.5 +/- 0.6 mg/kg day. Baseline evaluation revealed extreme short stature (mean height SD score = -3.7 +/- 1.2), delayed skeletal maturation (mean delay, 3.1 yr), and slowed growth rates (mean, 3.0 +/- 2.5 cm/yr). After 12 months of GH therapy (mean dose, 0.29 mg/kg x weeks), mean growth rate increased to 6.3 +/- 2.6 cm/yr, and height SD score improved by 0.21 +/- 0.4 (P < 0.01). During the second year of GH therapy (n = 44), the mean growth rate was 6.3 +/- 2.0 cm/yr. Prednisone equivalent dose and growth response to GH therapy were negatively correlated (r = -0.264; P < 0.05). Plasma concentrations of IGF-I, IGF-binding protein-3, procollagen, osteocalcin, and glycosylated hemoglobin increased with GH therapy, whereas glucose and insulin levels did not change. The following conclusions were reached. The growth-suppressing effects of GC are counterbalanced by GH therapy; the mean response is a doubling of baseline growth rate. Responsiveness to GH is negatively correlated with GC dose. Glycosylated hemoglobin levels increased slightly, but glucose and insulin levels were not altered by GH therapy.

National Cooperative Growth Study substudy VI: the clinical utility of growth-hormone-binding protein, insulin-like growth factor I, and insulin-like growth factor-binding protein 3 measurements.

OBJECTIVE: To assess the clinical utility of growth-hormone-binding protein (GHBP), along with growth hormone (GH), insulin-like growth factor I (IGF-I), and insulin-like growth factor-binding protein 3 (IGFBP-3), levels in the evaluation of short stature. STUDY DESIGN: Prospective substudy of the National Cooperative Growth Study, a multicenter observational study. RESULTS: A total of 6447 assessable subjects undergoing workup for short stature were enrolled at 197 sites. At baseline the cause of short stature was undefined in 77% of subjects. Mean GHBP levels were lowest in subjects with renal disease and highest in those with Turner syndrome. No cases of complete GH insensitivity syndrome (Laron syndrome) were identified. Subjects with low GHBP levels were among those tested for GH receptor mutations. IGF-I standard deviation scores (SDS) and IGFBP-3 SDS were positively correlated; both increased during GH therapy. There was a weak positive correlation between log peak GH levels and both IGF-I SDS and IGFBP-3 SDS and a weak negative correlation between log peak GH levels and GHBP SDS. Mean changes in GHBP SDS in subjects treated with GH and untreated subjects were not significant. Change in height SDS in subjects treated with GH was negatively correlated with age and IGF-I level but not correlated with baseline GHBP SDS. CONCLUSION: GHBP levels are GH independent and not predictive of responses to GH therapy, although low GHBP levels may indicate GH receptor abnormalities and partial GH insensitivity.