Eelco J. Schroor

Beneficial Effects of Growth Hormone Treatment on Cognition in Children with Prader-Willi Syndrome: A Randomized Controlled Trial and Longitudinal Study

BACKGROUND Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited. METHODS Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores. RESULTS During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores. CONCLUSIONS Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.

Efficacy and Safety of Long-Term Continuous Growth Hormone Treatment in Children with Prader-Willi Syndrome

BACKGROUND Children with Prader-Willi syndrome (PWS) have abnormal body composition and impaired growth. Short-term GH treatment has beneficial effects. OBJECTIVES The aim of the study was to investigate effects of long-term continuous GH treatment on body composition, growth, bone maturation, and safety parameters. SETTING We conducted a multicenter prospective trial. DESIGN Fifty-five children with a mean +/- sd age of 5.9 +/- 3.2 yr were followed during 4 yr of continuous GH treatment (1 mg/m(2) . d). Data were annually obtained in one center: fat percentage (fat%) and lean body mass (LBM) by dual-energy x-ray absorptiometry, height, weight, head circumference, bone age, blood pressure, and fasting IGF-I, IGF binding protein-3, glucose, insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, and low-density lipoprotein. sd scores (SDS) were calculated according to Dutch and PWS reference values (SDS and SDS(PWS)). RESULTS Fat%SDS was significantly lower after 4 yr of GH treatment (P < 0.0001). LBMSDS significantly increased during the first year (P = 0.02) but returned to baseline values the second year and remained unchanged thereafter. Mean +/- sd height normalized from -2.27 +/- 1.2 SDS to -0.24 +/- 1.2 SDS (P < 0.0001). Head circumference SDS increased from -0.79 +/- 1.0 at start to 0.07 +/- 1.1 SDS after 4 yr. BMISDS(PWS) significantly decreased. Mean +/- sd IGF-I and the IGF-I/IGF binding protein-3 ratio significantly increased to 2.08 +/- 1.1 and 2.32 +/- 0.9 SDS, respectively. GH treatment had no adverse effects on bone maturation, blood pressure, glucose homeostasis, and serum lipids. CONCLUSIONS Our study in children with PWS shows that 4 yr of continuous GH treatment (1 mg/m(2) . d) improves body composition by decreasing fat%SDS and stabilizing LBMSDS and head circumference SDS and normalizes heightSDS without adverse effects. Thus, long-term continuous GH treatment is an effective and safe therapy for children with PWS.

Eight Years of Growth Hormone Treatment in Children With Prader-Willi Syndrome : Maintaining the Positive Effects

BACKGROUND The most important reason for treating children with Prader-Willi syndrome (PWS) with GH is to optimize their body composition. OBJECTIVES The aim of this ongoing study was to determine whether long-term GH treatment can counteract the clinical course of increasing obesity in PWS by maintaining the improved body composition brought during early treatment. SETTING This was a multicenter prospective cohort study. METHODS We have been following 60 prepubertal children for 8 years of continuous GH treatment (1 mg/m(2)/d ≈ 0.035 mg/kg/d) and used the same dual-energy x-ray absorptiometry machine for annual measurements of lean body mass and percent fat. RESULTS After a significant increase during the first year of GH treatment (P < .0001), lean body mass remained stable for 7 years at a level above baseline (P < .0001). After a significant decrease in the first year, percent fat SD score (SDS) and body mass index SDS remained stable at a level not significantly higher than at baseline (P = .06, P = .14, resp.). However, body mass index SDSPWS was significantly lower after 8 years of GH treatment than at baseline (P < .0001). After 8 years of treatment, height SDS and head circumference SDS had completely normalized. IGF-1 SDS increased to +2.36 SDS during the first year of treatment (P < .0001) and remained stable since then. GH treatment did not adversely affect glucose homeostasis, serum lipids, blood pressure, and bone maturation. CONCLUSION This 8-year study demonstrates that GH treatment is a potent force for counteracting the clinical course of obesity in children with PWS.

Adult Height in Short Children Born SGA Treated with Growth Hormone and Gonadotropin Releasing Hormone Analog: Results of a Randomized, Dose-Response GH Trial

CONTEXT GH treatment is effective in improving height in short children born small for gestational age (SGA). GH is thought to have limited effect when started during adolescence. OBJECTIVE The aim of this study was to investigate GH treatment efficacy in short SGA children when treatment was started during adolescence; to assess whether GH 2 mg/m(2) · d during puberty improves adult height (AH) compared with 1 mg/m(2) · d; and to assess whether an additional 2-yr postponement of puberty by GnRH analog (GnRHa) improves AH in children who are short at the start of puberty (<140 cm), with a poor AH expectation. PATIENTS AND DESIGN In this longitudinal, randomized, dose-response GH trial, we included 121 short SGA children (60 boys) at least 8 yr of age. We performed intention-to-treat analyses on all children and uncensored case analyses on 84 children who reached AH. Besides, we evaluated growth during 2 yr of combined GH/GnRHa and subsequent GH treatment until AH in a subgroup of 40 pubertal children with a height of less than 140 cm at the start. RESULTS Short SGA children started treatment at a median age of 11.2 yr, when 46% had already started puberty. Median height increased from -2.9 at start to -1.7 sd score (SDS) at AH (P < 0.001). Treatment with GH 2 vs. 1 mg/m(2) · d during puberty resulted in significantly better AH (P = 0.001), also after correction for gender, age at start, height SDS at start, treatment years before puberty, and target height SDS. AH was similar in children who started puberty at less than 140 cm and received GH/GnRHa, compared with children who started puberty greater than 140 cm and received GH only (P = 0.795). CONCLUSION When started in adolescence, GH treatment significantly improves AH in short SGA children, particularly with GH 2 mg/m(2) · d during puberty. When SGA children are short at the start of puberty, they can benefit from combined GH/GnRHa treatment.

The effect of prolonged administration of an anabolic steroid (oxandrolone) on growth in boys with constitutionally delayed growth and puberty.

Short-term oxandrolone treatment is used to stimulate growth in boys with constitutional delay of growth and puberty (CDGP). Oxandrolone stimulates growth, but a beneficial effect on final height has not been established. In our study, we report the effect of long-term treatment (30–57 months) with oxandrolone in 18 boys with CDGP, compared with nine puberty-matched, untreated controls (group 1). The oxandrolone-treated boys were divided into two groups: four boys who received oxandrolone before onset of puberty (group 2), and 14 boys who started oxandrolone therapy during Tanner stage 2 (group 3). Height standard deviation scores for calender age (HSDSCA) between the three groups of patients at Tanner stage 2 (G2) were not different: −2.86 (SD 0.56) in the controls and −2.60 (SD 0.52) in group 2 and −2.81 (SD 0.59) in group 3. Age at G2 was 15.1 (SD 1.4) years (controls), 14.6 (SD 0.5) years (group 2) and 14.0 (SD 0.9) years (group 3). Height velocity in the time span from G2 to G5 was more pronounced in the oxandrolone-treated boys: 7.7 (SD 0.5) cm/year in group 2 and 7.7 (SD 1.4) cm/year in group 3 versus 5.1 (SD 0.9) cm/year in the controls. Height gain was significantly increased in the oxandrolone treated groups: 25.8 (SD 3.8) in group 2 and 25.2 (SD 3.7) in group 3 versus 19.8 (SD 4.9) in the controls (P<0.05). Final height did not differ significantly among the three groups: 168.5 (SD 7.0) cm in the controls and 173.0 (SD 4.0) cm in group 2 and 167.8 (SD 5.3) cm in group 3. HSDSCA increased during puberty in all three groups. At final height, HSDSCA (calculated at age=20 years) was −2.01 (SD 1.05), −1.34 (SD 0.59) and −2.12 (SD 0.79) respectively in groups 1, 2 and 3. An effect of oxandrolone on HSDSCA was not found. Target height was neither reached by the controls nor by the treated groups. Tempo of pubertal development was not different in the three groups, and ΔBA/ΔCA did not alter after start of oxandrolone treatment in groups 2 and 3.ConclusionBoys with CDGP may benefit from oxandrolone treatment in terms of increased height gain. Starting treatment before the onset of puberty may be favourable.

Bioactivity of Luteinizing Hormone during Normal Puberty in Girls and Boys

In order to evaluate the in vitro bioactivity of LH during normal puberty compared to LH immunoactivity measured in a highly sensitive immunoassay, blood plasma samples from healthy children were analyzed in a mouse Leydig cell assay (MLCA). Blood samples were obtained from 60 healthy girls and boys during normal pubertal development. Samples were taken on two occasions with a 1-year interval. Three daytime samples and three nighttime samples were analyzed. The correlation of the LH immunoradiometric assay (IRMA) activity with the LH activity in the MLCA varied from 0.60 to 0.96 in the different pubertal stages. During pubertal development, a gradually increase in the activity of LH in both the IRMA and MLCA was found. The ratio of the in vitro bioactivity compared to the immunoreactivity (B/I ratio) did not change significantly during puberty: it was 0.84 (SD 0.58) and 0.66 (SD 0.40) during the first and second sampling period in girls and 0.88 (SD 0.38) and 0.91 (SD 0.46, NS) in the boys. The B/I ratio of LH does not change during puberty. With a high sensitivity and specificity, measurement of LH by IRMA gives representative measurements of the LH in vitro bioactivity in children during pubertal development.

Metabolic Health in Short Children Born Small for Gestational Age Treated With Growth Hormone and Gonadotropin-Releasing Hormone Analog : Results of a Randomized, Dose-Response Trial

CONTEXT Previously we showed that pubertal children born small for gestational age (SGA) with a poor adult height (AH) expectation can benefit from treatment with GH 1 mg/m(2) per day (∼ 0.033 mg/kg/d) in combination with 2 years of GnRH analog (GnRHa) and even more so with a double GH dose. GnRHa treatment is thought to have negative effects on body composition and blood pressure. Long-term effects and GH-dose effects on metabolic health in children treated with combined GH/GnRHa are unknown. OBJECTIVE This study aimed to investigate body composition, blood pressure, and lipid profile during GH treatment, either with or without 2 years of additional GnRHa. To assess whether GH 2 mg/m(2) per day (∼ 0.067 mg/kg/d) results in a similar or even more favorable metabolic health at AH than GH 1 mg/m(2) per day. METHODS This was a longitudinal, randomized, dose-response GH trial involving 107 short SGA children (58 girls) treated with GH until AH (GH randomized 1 or 2 mg/m(2)/d during puberty). Sixty-four children received additional GnRHa. At AH, metabolic parameters were compared between children treated with combined GH/GnRHa and those with only GH. The GH dose effect on metabolic health was evaluated in a subgroup of 47 children who started GH treatment in early puberty (randomized 1 or 2 mg/m(2)/d) with 2 years of GnRHa. RESULTS At AH, fat mass percentage (FM%) SD score (SDS), lean body mass (LBM) SDS, blood pressure SDS, and lipid profile were similar between children treated with combined GH/GnRHa and those with only GH. In the pubertal subgroup, FM% SDS was lower during treatment with GH 2 mg/m(2) per day. There was no GH dose-dependent effect on LBM SDS, blood pressure, and lipid profile. CONCLUSIONS Combined GH/GnRHa treatment has no long-term negative effects on metabolic health compared with only GH. Started in early puberty, a GH dose of 2 mg/m(2) per day results in a similar metabolic health at AH and a more favorable FM% than GH 1 mg/m(2) per day.

Randomized GH trial with two different dosages in combination with a GnRH analogue in short small for gestational age children: effects on metabolic profile and serum GH, IGF1, and IGFBP3 levels

BACKGROUND GnRH analogue (GnRHa) combined with GH treatment has been proposed to increase adult height. Effect on metabolic profile and GH, IGF1, and IGFBP3 levels in short small for gestational age (SGA) children is unknown. OBJECTIVE To assess fat mass and lean body mass SDS, percentage trunk fat, blood pressure (BP), insulin sensitivity (Si), beta-cell function (disposition index, DI), lipid profile, and GH, IGF1, and IGFBP3 levels during 2 years of combined treatment. SUBJECTS Forty-one pubertal short SGA children with a mean (+/-S.D.) age of 12.1 (+/-1.0) years. DESIGN Children received 3.75 mg of leuprolide acetate depot subcutaneously every 4 weeks, and they were randomly assigned to receive 1 mg (group A) or 2 mg (group B) of GH/m(2) per day. RESULTS Percentage trunk fat increased in both groups, but to a lower extent in group B. Lean body mass SDS increased only in group B. Changes in BP, Si, DI, and lipids were similar in both groups. Si significantly decreased, but DI remained unchanged. Lipids remained normal. GH and IGF1 levels were significantly higher in group B. CONCLUSION Our study is the first to report that 2 years of combined treatment with a GnRHa and either 1 or 2 mg GH/m(2) per day does not adversely affect body composition and metabolic profile of short SGA children who come under medical attention at the onset of puberty. There was a dose-dependent effect on fat mass SDS(height), percentage trunk fat, lean body mass SDS(height), and GH and IGF1 levels in favor of treatment with GnRHa and the higher GH dose of 2 mg/m(2) per day.

THE RELATION BETWEEN BIOACTIVE AND IMMUNOACTIVE LH DURING PUBERTY

During puberty an Increase In LH secretion, as measured by RIA, Is observed. Other studies have reported an increasing ratio of bioactivity over Immunoactivity of LH during puberty. In order to study the relationship between In-vitro biological (bLH) and immunological (ILH) LH secretion during normal pubertal development, bLH and ILH was measured in 62 normal children (31 boys, 31 girls) in different stages of puberty. Plasma samples were derived at 1 hour intervals during 3 hours daytime and 3 hours nighttime. BLH was measured by the Mouse Leydig Cell Assay (MLCA) and ILH was measured by IRMA.Results: Boys: mean bLH and mean ILH significantly increased during puberty, with a maximum at G4 (G1: day + night bLH <0.3 U/l and day + night ILH <0.3 U/l; G4: day bLH 1.36 U/l sd 0.63, night 3.57 U/l sd 1.43; day ILH 1.14 U/l sd 0.62, night 4.33 U/l sd 1.29; Kruskai-Wallls oneway anova.p<0.01). A correlation is found between bLH and ILH, in all samples studied during daytime and nighttime (R = 0.85. p<0.01). At daytime, the ratio of the In-vitro bioactivity and the Immunoactivity (B/l ratio) Is 1.3 sd 0.2 in stages G2-G4, significantly higher compared to B/l 0.7 sd 0.2 In G5 (K-W oneway anova, p<0.05). During night B/l ratio is <1 and does not differ in all stages. Girls: for both bLH and ILH a significant increase during puberty is seen, with a maximum at M4 (M1: day + night bLH. day + night ILH <0.3 U/l; M4: day bLH 1.87 U/l sd 1.03, night 2.63 U/l sd 1.29; day ILH 2.45 U/l sd 1.73, night 5.03 U/l sd 2.37; K-W oneway ANOVA, p<0.01). BLH significantly correlates with ILH (R = 0.87, p<0.01). In contrast to boys, no significant changes In B/l ratio are detected in girls during puberty. In conclusion: during normal puberty, the changing LH In-vitro bioactlvity significantly correlates with ILH. In girls the LH B/l ratio does not change. In boys an Increased B/l ratio is found in stages G2-G4 during the day, which may be due to the low daytime testosterone levels, associated with the day-night rhythm.