Short stature in Noonan syndrome: response to growth hormone therapy.

BACKGROUND: Growth hormone (GH) has been used to promote growth in both the short and long term in a number of dysmorphic syndromes, including Turner syndrome. As this condition shares many clinical features with Noonan syndrome, it would seem logical to treat the latter group with GH. AIMS: To assess the short and long term response to GH therapy in patients with Noonan syndrome. METHODS: Analysis of patients with Noonan syndrome in the Pharmacia & Upjohn International Growth Study (this post-marketing database contains data on the majority of patients currently treated with GH in the UK). A questionnaire was also sent to participating clinicians. RESULTS: Data on 66 patients (54 males) were available for study. At the start of GH therapy children were short, compared with both normal and Noonan children. During the first year of GH therapy height velocity increased from a mean of 4.9 to 7.2 cm per year. For patients treated long term with GH, mean height SDS increased from -2.9 pretreatment to -2.6 after one year and -2.3 after five years. Of the 10 patients at near final height, only one had a height above the 3rd centile for normal adults and above the mean for untreated Noonan patients. The mean increment in final height was 3.1 cm (range -1.1 to 6.5 cm). CONCLUSIONS: GH therapy in patients with Noonan syndrome will improve height velocity in the short term. Longer-term therapy results in a waning of effect; initial indications are that final height is not improved substantially in most patients.     

Growth hormone testing in short children and their response to growth hormone therapy

Because current concepts of growth hormone (GH) testing and GH treatment have become controversial, we investigated the GH secretory patterns in children with normal and short stature. Twenty-four-hour serum GH levels were evaluated in three groups of children. Group 1 was composed of children with normal height (mean height = 0.02 SD, n = 33); group 2 was composed of short children (less than 5th percentile, n = 63) with normal results on provocative GH testing; and group 3 was composed of short children (less than 5th percentile, n = 7) with subnormal results on provocative GH testing. Mean +/- SD (range) GH levels during 24-hour studies of GH secretion were 1.6 +/- 1.1 (0.5 to 5.6), 1.8 +/- 1.2 (0.6 to 6.3), and 0.9 +/- 0.4 (0.5 to 1.7) ng/ml in groups 1, 2, and 3, respectively. No statistical difference existed in mean GH levels between groups 1 and 2 or between groups 1 and 3. The mean GH concentration from 24-hour studies in group 2 children did not correlate with chronologic age, height standard deviation, growth rates, or insulin-like growth factor 1 levels. The linear growth rate of 26 of 28 children in group 2 who received GH therapy for 6 months improved by 2 cm/yr or more; the mean +/- SD growth rate was 4.0 +/- 1.3 and 8.8 +/- 2.0 cm/yr during control and treatment periods, respectively, for these 28 children. Mean GH levels from testing did not predict response to GH during 6 months of therapy. Children with slower growth rates responded better to GH therapy (p less than 0.05). We conclude that (1) in 24-hour studies, GH levels in normal children overlapped with those of short children, including those with classic GH deficiency, (2) in 24-hour studies, GH levels did not predict responses of linear growth to short-term GH treatment, nor did they correlate with children's heights or growth velocities, and (3) the majority of short children in group 2 treated with GH for 6 months had an increase in linear growth velocity, the mean +/- SD change being 4.8 +/- 2.0 cm/yr.     

Defective Growth Hormone (GH) secretion and short-term treatment in Noonan syndrome

Auxological and endocrine data from 12 prepubertal children (3 males, 9 females) with Noonan syndrome (NS) were compared with those of 15 children with constitutional short stature (CSS), 20 children with partial GH deficiency (GHD), and 6 children with Turner syndrome (TS). Four children With NS were treated with human growth hormone (hGH) (n=4) (25 units/m² week, divided on daily s.c. doses). In children with NS, the peak serum GH response to clonidine (5.4 ± 2.7 ug/L) and glucagon (7.4 ± 3.4 ug/L) were significantly lower than those for children with CSS (14.8 ±3.4 and 12.8 ± 2.8 ug/L respectively). Nine out of the 12 (75%) children with NS did not mount normal GH peak (10 ug/L or more) after provocation. The 12-h integrated GH secretion in the 3 children With NS who had normal GH response to provocation (2.7 ± 0.7 ug/L) was markedly lower compared to that for children with CSS (6.7 ±1.2 ug/L). The serum insulin-like growth factor-1 (IGF-l) concentrations were lower in children with NS (67 ± 32 ng/ml) vs CSS (165 ±35 ng/ml), but not different from those for GHD children (59 ± 33 ng/ml). In 4 children with NS, hGH therapy for a year increased height growth velocity from 4.1 ± 0.3 cm/yr to 7.4 ±0.6 cm/yr and height standard deviation score (Ht SDS) from -2.2 ± 0.6 to -1.45 ±0.3. This growth acceleration was accompanied by an increase in IGF-I concentration (from 52 ±21 ng/ml to 89 ± 25 ng/ml). In summary, these results prove a defect of the GH secretion in children with NS and suggest that GH therapy has an important role in the management of their short stature.     

Growth Hormone Secretion and Growth Hormone Treatment in Children with Intrauterine Growth Retardation

Albertsson-Wikland, K. (Departments of Paediatrics II and Physiology, University of Gothenburg, Gothenburg, Sweden). Growth hormone secretion and growth hormone treatment in children with intrauterine growth retardation. Acta Paediatr Scand [Suppl] 349: 35, 1989.
Few children with intrauterine growth retardation (IUGR) fail to show catch-up growth during the first year of life. There may he many reasons for this, ranging from disturbances of hormone production to hormonal unresponsiveness of target cells. This report presents preliminary data on growth hormone (GH) secretion and responses to GH treatment in 16 children with IUGR and poor catch-up growth, six of whom had Silver-Russell stigmata. GH secretion was assessed by measurement of the GH response to an arginine-insulin test and determination of spontaneous GH secretion over 24 hours. GH production was heterogeneous hut, more often than expected, children showed both a low response to GH provocation and low spontaneous secretion of GH. Five out of six of the children with Silver-Russell syndrome and seven out of 10 of the children with non-Silver-Russell IUGR gained more than 2 cm in height during 1 year of treatment with GH at a dose of 0.1 IU/kg/day. These results clearly demonstrate that some children with IUGR and poor catch-up growth secrete insufficient amounts of GH, and that many of these very short children show an improvement in growth rate during treatment with physiological doses of GH.     

Improved final height with long-term growth hormone treatment in Noonan syndrome

Aim: To assess whether children with Noonan syndrome on long-term growth hormone (GH) therapy improve their final height to near mid-parental height. Methods: Twenty-five prepubertal children (13 girls) with Noonan syndrome (NS) were studied. A single clinician made the diagnosis based on clinical criteria. GH treatment started at an age ranging from 3.1 to 13.8 y and was continued for at least 2 y. Improvement or “gain” in final height (FH) was defined as either the difference between adult height SD scores (SDS) and pre-treatment height SDS (the childhood component of the Swedish reference) or height SDS compared to the Noonan reference. Results: Ten children received a GH dose of 33 μg/kg/d (mean age at start 7.7±2.1 y, mean age at stop 17.6±1.7 y) and 15 received a dose of 66 μg/kg/d (mean age at start 8.6±3.3 y, mean age at stop 18.4±2.1 y). Eighteen out of 25 patients reached FH. A substantial improvement in FH of 1.7 SDS, equivalent to 10.4 cm compared to pre-treatment height, was observed. No significant difference was seen between the two GH doses. Females gained a mean height of 9.8 cm and males 1-13 cm (FH 174.5±7.8 cm vs mean adult height of 162.5±5.4 cm for males with NS) at final height. Moreover, 60% reached a mid-parental height of±1 SD.

Conclusion: GH treatment improves final height in patients with Noonan syndrome, with a mean gain of 1.7 SDS. The prepubertal height gain is maintained to final height and the children achieve a height close to their mid-parental height.     

Ullrich-Turner-Syndrom und Noonan-Syndrom

Some of the phenotypic features of Noonan syndrome (NS) resemble those of Ullrich-Turner syndrome (UTS), but on the other hand there are striking differences between these two syndromes. The incidence of UTS is 1:2000–2500 in liveborn females, the incidence of NS is 1:1000–2500 live births. Patients with UTS are females and have gonadal dysgenesis, short stature, characteristic physical features, and a complete or partial X monosomy in some or all cells. Short stature and hypogonadism are the main problems in this syndrome. Mean final height in UTS is 20 cm below normal female adult height. Growth hormone (GH) treatment can increase adult height markedly if started early. Only some girls with UTS undergo spontaneous pubertal development. Boys and girls with NS have distinctive dysmorphic features, short stature, and congenital heart defects, while the karyotype is normal. The main problems are congenital heart disease and short stature. Patients with NS seem to benefit from GH treatment, but so far it is unclear whether adult height is increased, too. GH treatment for short stature in NS is not yet officially approved.     

Response to growth hormone treatment and final height in Noonan syndrome in a large cohort of patients in the KIGS database

BACKGROUND: Noonan syndrome (NS) is an autosomal dominant inherited disease, characterized by a distinctive facial appearance, congenital heart defects, and short stature. Treatment with growth hormone (GH) is an option to enhance height, but long-term effects are still unclear. PATIENTS AND METHODS: A cohort of 402 patients (269 males, 133 females), mean age 9.7 years at start with GH, was studied within the KIGS International growth database with respect to long-term response to GH therapy and final height after GH therapy. RESULTS: At the start of GH therapy median height was -2.61 SDS (Tanner 1966 standards). Seventy-three patients who were followed longitudinally for 3 years had an increment in height SDS (Ht SDS) over the first 3 successive years of 0.54, 0.13 and 0.13, respectively. Twenty-four patients had reached their final height after 4-12 years of GH treatment. Their Ht SDS increased from a median of -3.28 to a median of -2.41 at final height. CONCLUSION: This group of patients with NS showed an early response to GH treatment, with an attenuation of this effect thereafter. At final height the median increment of final height was 0.61 SDS according to Tanner standards and 0.97 SDS according to Noonan standards. No serious side effects were reported.     

Growth hormone treatment in 35 prepubertal children with achondroplasia: a five-year dose-response trial

BACKGROUND: Achondroplasia is a skeletal dysplasia with extreme, disproportionate, short stature. AIM: In a 5-y growth hormone (GH) treatment study including 1 y without treatment, we investigated growth and body proportion response in 35 children with achondroplasia. METHODS: Patients were randomized to either 0.1 IU/kg (n = 18) or 0.2 IU/kg (n = 17) per day. GH treatment was interrupted for 12 mo after 2 y of treatment in prepubertal patients to study catch-down growth. Mean height SDS (HSDS) at start was -5.6 and -5.2 for the low- and high-dose groups, respectively, and mean age 7.3 and 6.6 y. RESULTS: Mean growth velocity (baseline 4.5/4.6 cm/y for the groups) increased significantly by 1.9/3.6 cm/y during the first year and by 0.5/1.5 cm/y during the second year. During the third year, a decrease of growth velocity was observed at 1.9/1.3 cm/y below baseline values. HSDS increased significantly by 0.6/0.8 during the first year of treatment and in total by 1.3/1.6 during the 5 y of study. Sitting height SDS improved significantly from -2.1/-1.7 to -0.8/0.2 during the study. Body proportion (sitting height/total height) or arm span did not show any significant change. CONCLUSION: GH treatment of children with achondroplasia improves height during 4 y of therapy without adverse effect on trunk-leg disproportion. The short-term effect is comparable to that reported in Turner and Noonan syndrome and in idiopathic short stature.     

Anabolic steroid and gonadotropin releasing hormone analog combined treatment increased pubertal height gain and adult height in two children who entered puberty with short stature

We studied the effect of gonadal suppression treatment in combination with anabolic steroid on pubertal height gain and adult height in two children who entered puberty with short stature. Patient 1 was a female with idiopathic short stature. She received combined treatment with an anabolic steroid (stanozolol) and a gonadotropin releasing hormone analog (leuprorelin acetate). Her pubertal height gain was 28.5 cm, which is greater than that in normal height girls (20-25 cm). Patient 2 was a male with Aarskog syndrome. Although his growth hormone (GH) secretion was normal, he received GH treatment. Since GH administration did not accelerate his growth, he received combined treatment with stanozolol and leuprorelin acetate. His pubertal height gain was 27.0 cm, which is greater than that observed in GH deficient boys treated with GH alone (21.9 cm). Combined treatment with stanozolol and leuprorelin acetate appears to be effective in increasing pubertal height gain and adult height in children who enter puberty with short stature.     

Hypothalamic-pituitary dysfunction in primary empty sella syndrome in childhood

In a series of 37 consecutive CT scans performed in children referred to our pediatric endocrine unit, an empty (eight) or partially empty (one) sella turcica was found in nine (24%) patients with short stature or delay in sexual maturation, precocious puberty, or hypoparathyroidism. The size and contour of the sella were abnormal in only three patients. Five of the nine children had evidence of decreased growth hormone secretion as determined by subnormal GH secretory responses to provocative tests (peak GH concentration less than 7 ng/ml) or assessment of endogenous 24-hour GH secretion (mean 24-hour GH concentration less than 3 ng/ml). Two children had multiple pituitary hormone deficiencies. Although primary empty sella syndrome was often associated with hypothalamic-pituitary dysfunction in this series, the prevalence of an empty sella in normal children is unknown. Further identification and evaluation of children with empty sella may provide new information regarding the cause of pituitary dysfunction in childhood.     

Modulation of glucocorticoid secretion by growth hormone

We measured the cortisol and corticosterone responses to insulin-induced hypoglycemia in 13 growth hormone (GH)-deficient children and 30 short children without GH deficiency. Although there was no difference between the two groups in degree of hypoglycemia attained, baseline cortisol, baseline corticosterone, or cortisol 40 min after insulin injection, GH-deficient children had a significantly greater corticosterone response to this stress (3.6 +/- 0.4 versus 1.9 +/- 0.2 micrograms/dl). (All data are presented as mean +/- SEM.) In order to explore the effect of GH on corticosterone secretion, we measured cortisol and corticosterone responses to synthetic (1-24) ACTH before and after 3 days of exogenous GH (0.2 unit/kg/day). In 13 GH-deficient children, GH treatment caused a significant decrease in the corticosterone response to ACTH (2.2 +/- 0.2 micrograms/dl before GH to 1.6 +/- 0.2 micrograms/dl; t = 5.22, p less than 0.001; paired t test) despite the fact that there was no significant change in the cortisol response to ACTH (18 +/- 2 micrograms/dl before and 16 +/- 2 micrograms/dl after). When seven short children who were not GH deficient underwent a similar 3-day course of GH, the decrease in their corticosterone response was much less although still statistically significant (2.0 +/- 0.5 to 1.8 +/- 0.5 micrograms/dl; paired t test, p less than 0.05). Again, the stimulated levels of cortisol were not affected by GH treatment (19 +/- 4 versus 18 +/- 3 micrograms/dl) These results indicate that GH modulates the adrenal response to ACTH by suppressing corticosterone secretion without affecting cortisol secretion. In summary, this study presents two new findings.(ABSTRACT TRUNCATED AT 250 WORDS)     

Growth hormone for short stature not due to classic growth hormone deficiency

The advent of recombinant DNA technology has resulted in potentially unlimited supplies of growth hormone. Sufficient quantities are now available not only for the long-term, uninterrupted treatment of GH-deficient children but potentially for the treatment of non-GH-deficient patients with other short stature or growth attenuating disorders. Short-term studies have demonstrated an improvement in the growth rates of subjects with isolated short stature, Turner syndrome, and chronic renal failure; and additional studies are under way to assess the efficacy of GH therapy of other short stature syndromes. However, the long-term efficacy and possible adverse effects of GH treatment in these situations is not known. Until there has been more experience, GH deficiency should remain the primary indication for GH treatment. Growth hormone should not be considered routine therapy for other conditions associated with or resulting in short stature. However, research should continue in these areas to define which children may benefit from GH treatment.     

Predictors of growth response to growth hormone in otherwise normal short children.

Sixty prepubertal short children (39 boys) with heights less than 2 SD for age and gender were treated daily for 1 year with recombinant human growth hormone (GH), either 0.1 IU/kg (group 0.1, n = 32) or 0.05 IU/kg (group 0.05, n = 28). Reserve of GH was determined by at least one GH provocative stimulus and 24-hour continuous blood withdrawal to determine the integrated concentration of GH (IC-GH). All participants had a GH response to provocative tests greater than 10 micrograms/L. The height velocity (mean +/- SD) of the group as a whole increased from 4.46 +/- 1.02 to 7.59 +/- 1.65 cm/yr (p less than 0.001). The growth velocity of group 0.1 was significantly greater than that of group 0.05 (8.1 +/- 1.5 vs 7.0 +/- 1.65 cm/yr; p less than 0.01). Bone age did not advance more than 1 year during the treatment period. Growth velocity after 1 year of GH therapy was inversely correlated with the IC-GH in both groups, as was the pretreatment height velocity. We found no correlation of growth velocity during GH therapy with other measures such as parental heights, bone age/chronologic age ratio, maximal GH response to provocative tests, chronologic age, or pretreatment insulin-like growth factor I levels. We conclude that the best predictors for the 1-year growth outcome of short children with a normal GH response to provocative tests are the pretreatment growth velocity and the IC-GH. The short-term benefit from GH therapy in children with a normal growth velocity and a normal IC-GH is poor, whereas marked growth acceleration is noted in children with a low growth velocity and a low 24-hour IC-GH.     

Therapeutic Efficacy and Safety of GH in Japanese Children with Down Syndrome Short Stature Accompanied by GH Deficiency

In this study, we investigated the effects of GH treatment in children with Down syndrome who had been diagnosed with GH deficiency (GHD). A total of 20 subjects were investigated in this study. Fourteen Down syndrome children (5 boys and 9 girls) with short stature due to GHD were treated with GH at Okayama Red Cross General Hospital, and 6 Down syndrome children (4 boys and 2 girls) with short stature due to GHD were registered in the Pfizer International Growth Database (KIGS). Height SD score (SDS) increased throughout the three-year GH treatment period. The overall mean height SDS increased from –3.5 at baseline to –2.5 after 3 yr of treatment. The mean change in height SDS during these 3 yr was 1.1. In addition, height assessment of SD score based on Down syndrome-specific growth data in the Japanese population revealed that the height SDS (Down syndrome) also increased across the 3-yr GH treatment period. The mean change in height SDS (Down syndrome) during these three years was 1.3. GH therapy was effective for Down syndrome short stature accompanied by GHD, and no new safety concerns were found in this study.     

Twelve-hour spontaneous nocturnal growth hormone secretion in growth retarded patients

Twelve-hour nocturnal GH secretion was studied in 30 children with familial short stature (FSS), constitutional growth delay (CGD), total growth hormone deficiency (TGHD), partial growth hormone deficiency (PGHD), or idiopathic short stature (ISS). No difference was observed between subjects with FSS and children with CGD. The mean 12-hour serum GH concentration was significantly lower in patients with TGHD (p less than 0.001), children with PGHD (p less than 0.01), and subjects with ISS (p less than 0.01) than in subjects with FSS and CGD. No overlap was observed between the range of mean concentration values of children with TGHD and that of subjects with FSS. A significant correlation was found between growth velocity expressed as SD from the mean for bone age and GH concentration (p less than 0.001). All patients with a growth velocity less than 3rd percentile for bone age showed a mean nocturnal concentration less than 4 ng/ml. These data suggest that evaluation of 12-hour spontaneous nocturnal GH secretion with GH sampling every 30 minutes can be usefully employed in the diagnosis of GH deficiency.     

Effect of growth hormone therapy on feeding problems and food intake in children with growth disorders

To assess the effect of therapeutic doses of growth hormone (GH) on the feeding problems, food intake, body fat and mealtime interactions of children with growth disorders, an age-matched group of 46 children with Turner syndrome (TS) or Silver Russell syndrome (SRS) was examined using questionnaire measures and direct observation. The children's body fat was measured using bio-electrical impedance analysis and skinfold thickness measurements. Children receiving GH consumed significantly more energy, protein, fat and carbohydrate than did the children who were not receiving GH, independent of the extent of the child's feeding problems. Children receiving GH had less body fat than did children who were not receiving GH. Children who were not receiving GH distracted their parents from the mealtime significantly more often and received more negative prompting and coaxing from their parents to eat than did children who were receiving GH. This study provides evidence to support the theory that appetite and intake is determined in part by growth and growth potential. Feeding problems seen in children with growth disorders are partly due to parental attempts to impose control over their child's intake, when their child consumes less than the parent believes to be adequate. Conclusion: GH has a significant impact on both the food intake and parent-child interaction at mealtimes of children with SRS and TS.     

Prediction of the growth response in children with various growth disorders treated with growth hormone: analyses of data from the Kabi Pharmacia International Growth Study

Analyses to predict the growth response to recombinant human growth hormone (GH) in prepubertal children during the first year of treatment were performed on data from 472 patients with idiopathic GH deficiency (IGHD), 202 children with Turner's syndrome, 327 children with idiopathic short stature (ISS) and 135 children with intrauterine growth retardation (IUGR). In IGHD, 56% of the variability of the response could be predicted from a model based on six variables. These variables could be ranked in order of importance as follows: target height SDS minus height SDS, chronological age, frequency of GH injections, dose of GH, weight-for-height index, and birth weight SDS. When the model for IGHD was applied to Turner's syndrome, ISS and IUGR, there was a high degree of similarity between the predicted and achieved growth response in ISS and IUGR. However, an uneven distribution within the plot of Studentized residuals in ISS and IUGR suggested heterogeneity within these populations. Prediction of growth in Turner's syndrome was greatly exaggerated by the model for IGHD, suggesting a different pathogenesis as the basis of the growth disorder. Specific prediction models were therefore developed for Turner's syndrome, ISS and IUGR. In all three disorders, the dose of GH was found to be the most important predictor, suggesting that, in contrast to IGHD, first-year growth is governed less by the difference between height and the presumed genetically determined target height. Again, in contrast to IGHD, this suggests that catch-up phenomena are not involved. As the predictability of the variation in growth response in Turner's syndrome, ISS and IUGR did not exceed 32% (for ISS), the search for new predictors should continue in these disorders.     

Growth hormone therapy in pre-pubertal children with Noonan syndrome: first year growth response and comparison with Turner syndrome

We studied the growth-promoting effect of treatment with recombinant human growth hormone in 23 prepubertal children with Noonan syndrome, aged between 5. 4 and 14. 3 y, and all with a height < 1. 4 SD for Tanner standards. The growth response and skeletal maturation after 1 y of recombinant human growth hormone treatment (0. 15 U/kg/day given by daily injection) in the Noonan syndrome patients was compared with the auxological changes observed in a group of 17 girls with Turner syndrome with a comparable age and height deficit who were treated with recombinant human growth hormone in a similar way. During 1 y of treatment, the mean ± SD height velocity increased by 4. 0 ± 1. 6 cm/y in the Noonan syndrome group and by 3. 6 ± 1. 3 cm/y in the Turner syndrome group. Height SDS for chronological age in the Noonan syndrome group increased by 0. 53 ± 0. 46 ( p < 0. 001). In the Noonan syndrome patients the changes in height velocity were positively related to birthweight ( r = 0. 48, p < 0. 05). The changes in height velocity or height SDS were not related to the age, height deficit or a delay in bone age maturation at start of treatment. In neither the patients with Noonan syndrome nor Turner syndrome was an acceleration of bone maturation found. We conclude that treatment with recombinant human growth hormone in pre-pubertal NS patients induces an increase in height velocity and height SDS comparable to that observed in Turner syndrome girls.     

Evaluation of growth hormone release in children using arginine and L-dopa in combination.

L-Dopa in a dose ranging from 125-500 mg and arginine monochloride in a dose of 0.5 gm/kg were given simultaneously to 56 children with short stature (height less than third percentile). Sixteen of these children were subsequently diagnosed as having growth hormone deficiency. The diagnosis of hyposomatotropism was based on clinical findings and on responses to the combination test and to arginine and L-dopa administered as separate tests. All of the remaining 40 children had a normal GH response of greater than 6 ng/ml to the combination test. However, in this group, nine children were identified who responded to the combination test but who failed to respond to arginine and L-dopa in individual tests. The data suggest that a positive response to arginine and L-dopa in combination in children, who do not respond to the usual provocative tests when administered individually, may fail to identify children with partial GH deficiency who would benefit from treatment. The integrated stimulated GH response in the 31 children in whom a normal GH response to all three tests occurred suggests that the effects of L-dopa and arginine are additive.