Effect of growth hormone dose on bone maturation and puberty in children with idiopathic short stature.

CONTEXT: GH at 0.22 mg/kg.wk has been shown to have no effect on pubertal onset or pace, whereas GH at 0.5 mg/kg x wk has been shown to advance pubertal onset and bone maturation. OBJECTIVES: Our objectives were to determine whether 0.37 mg/kg x wk GH advanced pubertal onset, pace, or bone maturation relative to 0.24 mg/kg x wk GH; whether 0.37 mg/kg x wk GH led to pubertal onset at an inappropriately early age; and whether age at start of GH therapy influenced pubertal onset. DESIGN: We conducted a randomized, open-label study to final height. PATIENTS: We studied children with idiopathic short stature. INTERVENTION: Patients were treated with 0.24 mg/kg x wk, 0.24 increasing to 0.37 mg/kg x wk, or 0.37 mg/kg x wk. MAIN OUTCOME MEASURES: We assessed age at pubertal onset and rates of bone maturation, Tanner stage development, and increase in testicular volume (boys only). RESULTS: For the primary comparison between the 0.24 and 0.37 mg/kg x wk dose groups, median ages of pubertal onset (in years) were similar (13.7 vs. 13.5 for boys and 11.7 vs. 11.4 for girls) and were greater than those for the general population for each sex. Age at start of GH therapy did not appear to influence pubertal onset for either sex. Rates of pubertal pace and bone maturation were not significantly different between the 0.24 and 0.37 mg/kg x wk dose groups for either sex. CONCLUSION: GH at 0.37 mg/kg x wk does not appear to accelerate pubertal onset, pace, or bone maturation compared with GH at 0.24 mg/kg x wk in patients with idiopathic short stature. From a clinical standpoint, our results suggest that the approved dose range of up to 0.37 mg/kg x wk GH does not lead to pubertal onset at an inappropriately early age.

Safety of growth hormone treatment in pediatric patients with idiopathic short stature.

CONTEXT: Recombinant human GH was approved by the United States Food and Drug Administration in 2003 for the treatment of idiopathic short stature (ISS). However, to date, the safety of GH in this patient population has not been rigorously studied. OBJECTIVE: The objective of this study was to address the safety of GH treatment in children with ISS compared with GH safety in patient populations for which GH has been approved previously: Turner syndrome (TS) and GH deficiency (GHD). DESIGN/SETTING: The rates of serious adverse events (SAEs) and adverse events (AEs) of particular relevance to GH-treated populations were compared across the three patient populations among five multicenter GH registration studies. PATIENTS: Children with ISS, TS, or GHD were studied. INTERVENTION: Treatment consisted of GH doses ranging from 0.18-0.37 mg/kg.wk. MAIN OUTCOME MEASURES: The main outcome measures were rates of SAEs and AEs of special relevance to patients receiving GH. Laboratory measures of carbohydrate metabolism were used as outcome measures for the ISS studies. RESULTS: Within the ISS studies, comprising one double-blind, placebo-controlled study and one open-label, dose-response study, SAEs (mainly hospitalizations for accidental injury or acute illness unrelated to GH exposure) were reported for 13-14% of GH-treated patients. Overall AE rates (serious and nonserious) as well as rates of potentially GH-related AEs were similar in the GHD, TS, and ISS studies (for ISS studies combined: otitis media, 8%; scoliosis, 3%; hypothyroidism, 0.7%; changes in carbohydrate metabolism, 0.7%; hypertension, 0.4%). Measures of carbohydrate metabolism were not affected by GH treatment in patients with ISS. There was no significant GH effect on fasting blood glucose in either study (GH dose range, 0.22-0.37 mg/kg.wk) or on insulin sensitivity (placebo-controlled study only). CONCLUSION: GH appears safe in ISS; however, the studies were not powered to assess the frequency of rare GH-related events, and longer-term follow-up studies of GH-treated patients with ISS are warranted.

Growth hormone (GH) treatment to final height in children with idiopathic short stature: evidence for a dose effect.

OBJECTIVES: To investigate in an open-label randomized study, the effect of two doses of growth hormone (GH) on final height and height velocity during the first 2 years of treatment of children with idiopathic short stature (mean baseline height standard deviation score [SDS] -3.2). STUDY DESIGN: Patients were treated with GH at 0.24 mg/kg/week, 0.24 mg/kg/week for the first year and at 0.37 mg/kg/week thereafter (0.24-->0.37), or 0.37 mg/kg/week. Final height was evaluated in 50 patients at study completion (mean treatment duration, 6.5 years). RESULTS: Patients who received 0.37 mg/kg/week (n = 72) experienced a significantly greater increase in height velocity than those who received 0.24 mg/kg/week (n = 70) (treatment difference = 0.8 cm/year; P = .003) or 0.24-->0.37 mg/kg/week (n = 67) (treatment difference = 0.9 cm/year; P = .001). For the 50 patients for whom final height measurements were available, mean height SDS increased by 1.55, 1.52, and 1.85 SDS, respectively, for the three dose groups. For the primary comparison between the 0.37 mg/kg/week and 0.24 mg/kg/week dose groups, the mean treatment difference (adjusted for differences in baseline predicted height SDS) was 0.57 SDS (3.6 cm; P = .025). Mean overall height gains (final height minus baseline predicted height) were 7.2 cm and 5.4 cm for the 0.37 mg/kg/week and 0.24 mg/kg/week dose groups, respectively, without dose effects on safety parameters. Final height measurements were within the normal adult height range for 94% of patients randomized to 0.37 mg/kg/week who continued to final height. CONCLUSION: GH treatment dose-dependently increases height velocity and final height in children with idiopathic short stature.

Aging women with polycystic ovary syndrome who achieve regular menstrual cycles have a smaller follicle cohort than those who continue to have irregular cycles.

OBJECTIVE: To examine whether follicle loss due to ovarian aging is responsible for the occurrence of regular menstrual cycles in aging women with polycystic ovary syndrome (PCOS), the size of the FSH-sensitive follicle cohort was estimated by the exogenous follicle-stimulating hormone ovarian reserve test (EFORT) and related to the follicle count as measured by ultrasound. DESIGN: Prospective study. SETTING: Reproductive endocrinology unit of an academic medical center. PATIENT(S): Twenty-seven aging women with PCOS (35.8-49.4 years): 20 with regular menstrual cycles and 7 with oligomenorrhea or amenorrhea. INTERVENTION(S): EFORT and transvaginal ultrasound. MAIN OUTCOME MEASURE(S): Baseline (cycle day 2, 3, or 4) FSH, androstenedione (A), T, E(2), and inhibin B levels, the E(2) and inhibin B increment after the EFORT, and the follicle count. RESULT(S): After correction for the body mass index (BMI), the inhibin B increment was higher in the irregular menstrual group, but the E(2) increment did not differ significantly between the two groups. Ultrasound showed a median follicle count of 8.5 (4.0-18.0) in women with regular menstrual cycles (n = 16), compared with 18.0 (8.0-35.0) in irregularly menstruating women (n = 7). The follicle count was significantly correlated to the FSH-induced E(2) increment (r = 0.656) as well as to the inhibin B increment (r = 0.654). The regularly menstruating group was significantly older, had a higher basal FSH concentration, and had lower androgens than the irregularly menstruating group. CONCLUSION(S): The smaller follicle count, the older age, the higher FSH concentration, and the lower FSH-induced inhibin B increment found in women with PCOS and a regular menstrual cycle confirm that a decrease in the size of the follicle cohort due to ovarian aging is largely responsible for the regular menstrual cycles in aging PCOS women.