Efficacy and safety of long-term continuous growth hormone treatment of children born small for gestational age

Twelve years of growth hormone (GH) therapy of short children born small for gestational age (SGA) have demonstrated that GH is an effective and well-tolerated therapy. Most children will reach a normal adult height (AH). AH of 55 SGA adolescents was comparable for those treated with a GH dose of 1 or 2 mg/m2 (approximately 0.033 or 0.066 mg/kg) per day, mean (SD) AH SDS being -1.2 (0.7) and -0.8 (0.7), respectively. GH therapy had no influence on the age at onset, the progression of puberty, duration of puberty and pubertal height gain. GH therapy induced higher fasting and glucose-stimulated insulin levels after 1 and 6 years, but 6 months after GH stop, all levels returned to normal. At baseline mean systolic blood pressure was significantly increased, but both systolic and diastolic blood pressure decreased significantly during 6 years of GH and remained so after GH stop. GH therapy demonstrated a beneficial effect on serum lipid profiles, body composition, bone mineral density and head growth. Treatment with 2 mg GH/m2 per day induced mean serum IGF-I levels of +2 SDS, whereas IGF-I levels remained within the normal range with 1 mg GH/m2 per day. In conclusion, long-term GH therapy of short SGA children with 1 mg/m2 per day appears to be effective and safe. Since the future consequences of high serum IGF-I levels during long-term GH therapy with 2 mg/m2 per day are as yet unknown, it seems safer to treat short prepubertal SGA children with a GH dose of 1 mg/m2 per day when children are to be treated continuously for many years.     

Final height data, body composition and glucose metabolism in growth hormone-treated short children born small for gestational age

Low birth weight has been associated with impaired insulin sensitivity, type 2 diabetes mellitus, hypertension and cardiovascular disease in later life. GH therapy is known to increase fasting and postprandial insulin levels. For this reason concern has been expressed regarding the possible detrimental effects of GH therapy in children born small for gestational age (SGA). To assess the effects of GH therapy on body composition, carbohydrate metabolism and final height in short SGA children, 165 prepubertal short children born SGA were enrolled in either a multicentre, double-blind, randomized, dose-response GH trial (n = 75) or in a GH controlled trial (n = 90). The inclusion criteria were: (1) birth length standard deviation score (SDS) below -2; (2) age 3-8 years; (3) height SDS below -2. The children's mean (SD) age was 7.3 (2.1) years (GH dose-response trial) and 6.0 (1.5) years (GH controlled trial), birth length SDS was -3.6 and height SDS was -3.0 (0.7). In the GH dose-response trial, children were randomly assigned to either 1 mg GH/m(2) per day (group A, n = 41) or 2 mg GH/m(2) per day (group B, n = 38) ( approximately 0.033 or 0.067 mg/kg per day, respectively). In the GH controlled trial, children were randomly assigned to 1 mg GH/m(2) per day (n = 60) or served as controls (n = 30). Subjects underwent standard oral glucose tolerance tests and measurement of body mass index, systolic and diastolic blood pressure and serum lipids at baseline and after 1 and 6 years of GH therapy and again 6 months after discontinuation of GH. Body composition was measured by dual energy x-ray absorptiometry at baseline and again after 3 years in the GH controlled trial. Mean (SD) final height SDS was not significantly different between the two GH dosage groups: -1.2 (0.7) in group A and -0.8 (0.7) in group B. At the start of GH therapy, 8% of children had impaired glucose tolerance (IGT). Systolic blood pressure was significantly higher in comparison with healthy peers. GH therapy induced considerably higher fasting and glucose-stimulated insulin levels after 1 and 6 years, regardless of GH dosage. After 6 years, 4% of children had IGT. Six months after discontinuation of GH, glucose levels remained normal, whereas fasting and glucose-stimulated insulin returned to levels comparable to those of healthy peers. None of the children developed diabetes. During 6 years of GH therapy both systolic and diastolic blood pressure decreased significantly and remained so after discontinuation of GH therapy. At baseline all children had reduced bone mineral content and lean body mass. Fat mass was not significantly lower than normal. Treatment with 1 mg GH/m(2) per day resulted in a significant increase in (and normalization of) bone mineral content and lean body mass in comparison with untreated short SGA controls. Fat mass decreased during the first year of GH but returned to values comparable to those at baseline in the following 2 years of GH therapy. We found that long-term, continuous GH therapy in short children born SGA leads to a normalization of height during childhood and to a normal final height in most children, regardless of GH dosage. Only very short or relatively older children may need a dosage of 2 mg GH/m(2) per day. Long-term GH therapy had no adverse effects on glucose levels and serum lipids and had a positive effect on blood pressure, even with GH dosages of up to 2 mg/m(2) per day. However, as has been reported in other patient groups, GH induced higher fasting and glucose-stimulated insulin levels, indicating insulin resistance. After discontinuation of GH serum insulin levels returned to normal age-reference levels. Short SGA children have a reduction in bone mineral content and lean body mass when compared with healthy controls, which significantly improved (normalized) with GH therapy at a dose of 1 mg/m(2) per day.     

Adult height in patients treated for isolated growth hormone deficiency: role of birth weight

To evaluate the effect of growth hormone (GH) administration on adult height (AH) in two groups of isolated GH-deficient (IGHD) children born either small (birth weight below -2 SD) or appropriate (birth weight above -2 SD) for gestational age (GA). Out of 35 prepubertal IGHD children, 14 small for GA (SGA, group A) and 21 appropriate for GA (AGA, group B) were examined. All patients received continuous GH treatment at a median dose of 0.028 mg/kg/day (range 0.023-0.032) in group A and 0.024 (range 0.023-0.028) in group B. GH treatment was administered for a period of 67.0 months (range 42.37-96.05) in group A and 54.31 months (range 47.14-69.31) in group B. All children were measured using a Harpenden stadiometer every 6 months until they reached AH (growth velocity <1 cm/year). The patients underwent a retesting a few months after stopping GH therapy. A significant difference was found between group A and B as expected for birth weight SD, -2.70 (range -2.87 to -2.29) and -0.73 (range -1.30 to 0.14) respectively (p < 0.000001) and interestingly also for body mass index SDS (BMI SDS) at retesting, 0.08 (range 0.30 to -1.51) and 0.61 (range 0.73 to -1.10) respectively (p < 0.04). We observed no significant differences between groups A and B in height (expressed as the SDS for chronological age, height SDS) at diagnosis (p = 0.75), height SDS at start of puberty (p = 0.51), height SDS at retesting (p = 0.50), target height SDS (TH SDS) (p = 0.47), AH SDS (p = 0.92), corrected height SDS (height SDS - TH SDS) (p = 0.60), BMI SDS at diagnosis (p = 0.25), GH dosage (p = 0.34) and therapy duration (p = 0.52). GH treatment with a standard dose in short IGHD children leads to a normalization of AH without any significant difference between SGA and AGA patients.     

Growth hormone treatment strategy for short children born small for gestational age

Several studies performed in the last 15 years have shown that growth hormone (GH) induces a profound catch-up in height in short children born small for gestational age (SGA). We know from more recent studies that final height can be normalized through GH treatment. In Europe, GH is now a recognized indication, enabling treatment of short children born SGA. Treatment is given to the most severe growth-retarded children after the age of 4 years. A dose of 0.035 mg/kg per day is recommended. However, in our opinion a higher dose would be more efficient in very short children, especially if they are treated later in childhood.     

Final height in children with idiopathic growth hormone deficiency treated with a fixed dose of recombinant growth hormone

There is no consensus regarding the optimal dosing of recombinant human growth hormone (rhGH) for children with growth hormone deficiency (GHD). Our objective was to evaluate the final adult height (FAH) in children with idiopathic GHD treated with a fixed rhGH dose of 0.18 mg/kg/week. We reviewed all charts of patients with idiopathic GHD treated with rhGH since 1985 who reached FAH. Ninety-six patients were treated for an average of 5.4 years. The mean age was 11.9 years, the mean height -2.87 standard deviation score (SDS) and the mean FAH was -1.04 SDS. Females had a lower predicted adult height than males at the initiation of therapy (-2.0 vs. -1.01 SDS; p = 0.0087) but a higher FAH - predicted adult height (1.08 vs. 0.04 SDS; p = 0.0026). In multiple regression analysis, the FAH SDS was positively related to the midparental height SDS, the height SDS at GH initiation and growth velocity during the first year of therapy, and negatively correlated with peak GH and bone age at initiation (r(2) = 0.51; p < 0.005). Treatment of children with idiopathic GHD with a fixed dose of 0.18 mg/kg/week rhGH is sufficient to reach FAH within 2 SDS of the normal population range (84%) with an average FAH within -0.5 SDS of midparental height.     

Final height in children with idiopathic growth hormone deficiency treated with recombinant human growth hormone: the Belgian experience

BACKGROUND: The growth response to recombinant hGH (rhGH) treatment and final height of 61 Belgian children (32 boys) with idiopathic growth hormone deficiency (GHD) were studied. PATIENTS/METHODS: Two patient groups were compared: Group 1 with spontaneous puberty (n = 49), Group 2 with induced puberty (n = 12). The patients were treated with daily subcutaneous injections of rhGH in a dose of 0.5-0.7 IU/kg/week (0.17-0.23 mg/kg/week) from the mean +/- SD age of 11.9 +/- 3.1 years during 5.1 +/- 2.1 years. RESULTS: rhGH treatment induced a doubling of the height velocity during the first year and resulted in a normalisation of height in 53 (87%) patients. Final height was -0.7 +/- 1.1 SDS, being 170.4 +/- 7.2 cm in boys and 158.0 +/- 6.4 cm in girls. Corrected for mid-parental height, final height was 0.0 +/- 1.1 SDS. Ninety-two percent of the patients attained an adult height within the genetically determined target height range. Although height gain during puberty was smaller in the patients with induced puberty (boys: 17.1 +/- 7.0 cm vs. 27.5 +/- 6.6 cm (p < 0.005); girls: 9.6 +/- 7.4 cm vs. 22.2 +/- 6.1 cm (p < 0.005)), no differences in final height after adjustment for mid-parental height were found between patients with spontaneous or induced puberty. CONCLUSIONS: We conclude that patients with idiopathic GHD treated with rhGH administered as daily subcutaneous injections in a dose of 0.5-0.7 IU/kg/week reach their genetic growth potential, resulting in a normalisation of height in the majority of them, irrespective of spontaneous or induced puberty.     

Intermittent recombinant growth hormone treatment in short children born small for gestational age: four-year results of a randomized trial of two different treatment regimens

BACKGROUND: Treatment of short children born small for gestational age SGA with recombinant human growth hormone r-hGH increases growth velocity during childhood. As in other indications, the growth velocity in these patients is more marked during the first year of treatment and then decreases. This study was undertaken to evaluate the efficacy of different r-hGH treatment schedules (67 microg/kg/day in a discontinuous or continuous regimen) during the second year of r-hGH treatment by comparing height velocity changes and total gain of height over a 4-year period. METHODS: 58 growth-retarded SGA children aged 2-5 years were randomized to a TOTO regimen (4 years alternating treatment (T) and observation (O), n = 30) or a TTOO regimen (2 years' treatment, followed by 2 years' observation, n = 28). Height velocity HV and total height gain were assessed during the 4-year study. RESULTS: In both groups, HV and HV standard deviation score HV-SDSCA increased during treatment and decreased during observation periods. Interruption of treatment in the TOTO group did not result in a better gain in height standard deviation score H-SDSCA when compared with the TTOO group. After 4 years of study, the gain in H-SDSCA was 1.4 + or - 01 in the TOTO group and 1.6 + or - 0.2 in the TTOO group leading to a mean height of -2.0 + or - 1.0 SDS and -2.0 + or - 0.8 SDS, respectively. The rate of bone maturation was similar in the two groups. CONCLUSIONS: In short SGA children, TOTO and TTOO regimens produced significant improvements in growth during r-hGH treatment. However, treatment interruption after 1 year did not influence the overall gain in height SDS when compared with 2 years' continuous treatment.     

Serum leptin in short children born small for gestational age: dose-dependent effect of growth hormone treatment

OBJECTIVE: To study the effects of different regimens of growth hormone (GH) treatment on serum leptin levels in 78 short prepubertal children born small for gestational age (SGA). METHODS: The children were originally included in two independent multicenter trials, one in Belgium and one in the Nordic countries. SGA children were randomized either to remain untreated or to be treated with GH at a daily dose of 0.1, 0.2 or 0.3 IU/kg for 2 years. Thereafter, treatment was continued for another 2 years in the Nordic children, whereas it was discontinued in the Belgian children. RESULTS: In the GH treatment groups, a significant dose-dependent decrease in leptin levels was found during the first year of therapy, with a mean decrease of 13, 23 and 32% in the groups receiving GH at 0.1, 0.2 and 0.3 IU/kg, respectively. When high-dose treatment was interrupted, serum leptin increased within 1 year to pretreatment levels. CONCLUSION: Serum leptin levels in short children born SGA are transiently reduced by GH treatment in a dose-dependent fashion. The most pronounced changes in serum leptin were documented within the first year after initiation and withdrawal of high-dose GH treatment.     

Effects of growth hormone treatment on cognitive function and head circumference in children born small for gestational age

Short stature is not the only problem faced by children born small for gestational age (SGA). Being born SGA has also been associated with lowered intelligence, poor academic performance, low social competence and behavioural problems. This paper summarizes the results of a randomized, double-blind, growth hormone (GH) dose-response study (1 or 2 mg/m2/day [ approximately 0.035 or 0.07 mg/kg/day]) on growth, intelligence quotient (IQ) and psychosocial functioning in 79 children born SGA at the start, and after 2 and 8 years of GH therapy, and addresses the associations with head circumference. Mean age at start of therapy was 7.4 years; mean duration of GH treatment was 8.0 years. In 2001, 91% of children born SGA had reached a normal height (> -2.0 standard deviation score [SDS]). Block-design s-score (Performal IQ) and Total IQ score increased (p < 0.001 for both indices) from scores significantly lower than those of Dutch peers at the start of therapy (p < 0.001) to scores that were comparable to those of Dutch peers in 2001. Vocabulary s-score (Verbal IQ) was normal at the start of therapy and remained so over time. Externalizing Problem Behaviour SDS and Total Problem Behaviour SDS improved during GH therapy (p < 0.01-0.05) to scores comparable to those of Dutch peers. Internalizing Problem Behaviour SDS was comparable to that of Dutch peers at the start of therapy and remained so, whereas Self-Perception improved from the start of GH therapy until 2001 (p < 0.001), when it reached normal scores. Head circumference SDS at the start of GH therapy and head growth during GH therapy were positively related to all IQ scores (p < 0.01), whereas neither were related to height SDS at the start of, or to its improvement during, GH therapy. A significant improvement in height and head circumference in children born SGA was seen after only 3 years of GH therapy, in contrast to randomized SGA controls. In conclusion, most children born SGA showed a normalization of height during GH therapy and, in parallel to this, a significant improvement in Performal IQ and Total IQ. In addition, problem behaviour and self-perception improved significantly. Interestingly, Performal, Verbal and Total IQ scores were positively related to head circumference, both at the start of, and during, GH therapy; head circumference increased in GH-treated children born SGA, but not in untreated SGA controls. These results are encouraging but also warrant confirmational studies and further investigations into the effects of GH on the central nervous system.     

Methylphenidate and the Response to Growth Hormone Treatment in Short Children Born Small for Gestational Age

Background

Growth hormone (GH) treatment has become a frequently applied growth promoting therapy in short children born small for gestational age (SGA). Children born SGA have a higher risk of developing attention deficit hyperactivity disorder (ADHD). Treatment of ADHD with methylphenidate (MP) has greatly increased in recent years, therefore more children are being treated with GH and MP simultaneously. Some studies have found an association between MP treatment and growth deceleration, but data are contradictory.

Objective

To explore the effects of MP treatment on growth in GH-treated short SGA children

Methods

Anthropometric measurements were performed in 78 GH-treated short SGA children (mean age 10.6 yr), 39 of whom were also treated with MP (SGA-GH/MP). The SGA-GH/MP group was compared to 39 SGA-GH treated subjects. They were matched for sex, age and height at start of GH, height SDS at start of MP treatment and target height SDS. Serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) levels were yearly determined. Growth, serum IGF-I and IGFBP-3 levels during the first three years of treatment were analyzed using repeated measures regression analysis.

Results

The SGA-GH/MP group had a lower height gain during the first 3 years than the SGA-GH subjects, only significant between 6 and 12 months of MP treatment. After 3 years of MP treatment, the height gain was 0.2 SDS (±0.1 SD) lower in the SGA-GH/MP group (P = 0.17). Adult height was not significantly different between the SGA-GH/MP and SGA-GH group (−1.9 SDS and −1.9 SDS respectively, P = 0.46). Moreover, during the first 3 years of MP treatment IGF-I and IGFBP-3 measurements were similar in both groups.

Conclusion

MP has some negative effect on growth during the first years in short SGA children treated with GH, but adult height is not affected.     

Effects of growth hormone treatment on left ventricular dimensions in children with Noonan's syndrome

OBJECTIVE: To study the effects of long-term growth hormone (GH) treatment on left ventricular (LV) dimensions in children with Noonan's syndrome (NS). METHODS: Echocardiographic measurements of LV dimensions were performed before and during GH treatment in 27 participants (21 boys, 6 girls) in a partly controlled 3-year trial of high-dose GH treatment (0.15 IU/kg/day). Nineteen children had a congenital heart defect, 1 of them had hypertrophic obstructive cardiomyopathy. In the first 3 years, the children were assigned to 1 of 2 groups: group A with discontinuation of GH treatment in the 3rd year, or group B without GH treatment in the 1st year. After the 3rd year, 12 of the 27 children were followed up for 2 additional years to evaluate the long-term effects of GH treatment on the heart. RESULTS: At baseline, LV internal diameters were smaller, while posterior wall thickness were thicker than normal. Over the 1st year, changes in LV dimensions were comparable between the 2 groups. No significant differences were found in LV dimensions between the situation at baseline and after 4 years of GH treatment. CONCLUSION: Long-term high-dose GH treatment does not have clinically significant adverse effects on LV dimensions in children with NS.     

Growth response to growth-hormone administration during the decelerating phase of the pubertal growth spurt in short normal children

In order to investigate the value of growth hormone (GH) treatment during late puberty, we studied the effect of human GH (hGH) administration (0.85 +/- 0.30 IU/kg/week; range: 0.44-1.28) on height velocity (HV) after the peak of the pubertal growth spurt in a group of 10 (4 girls and 6 boys) short normal children (GH peak after pharmacological stimulation: 15.5 +/- 2.3 ng/ml) with growth retardation (height: 2.6 +/- 0.3 SD) and puberty Tanner stage 4. A group of 10 untreated children, observed prior to the study, served as controls. The children were regularly measured during their pubertal growth spurt, and HV (cm/year) was calculated every 6 months. The pretreatment evaluation consisted of 2 consecutive 6-month periods characterized by a decrease in HV of at least 25%. In the group of selected children, hGH administration was then initiated and growth variables were evaluated after 6 and 12 months of therapy. Skeletal maturation was evaluated at the beginning as well as after 6 months and 12 months of hGH therapy. In the controls, HV (mean +/- SD) had decreased from 8.8 +/- 1.8 to 4.9 +/- 1.4 cm/year during the pretreatment period (in girls from 7.9 +/- 1.4 to 4.1 +/- 0.6 cm/year and in boys from 9.6 +/- 1.6 to 5.8 +/- 1.2 cm/year). During the following semester, HV was 3.3 +/- 0.8 cm/year (girls: 3.4 +/- 1.0 and boys: 3.2 +/- 0.2 cm/year).(ABSTRACT TRUNCATED AT 250 WORDS)     

Food intake of children with short stature born small for gestational age before and during a randomized GH trial

Parents of short children born SGA often report that their children have a serious lack of appetite and a low food intake. In this study we investigated food intake, by using a standardized 7-day food questionnaire, in 88 short SGA children before start of GH treatment. The intake was compared with the recommended daily intake (RDI) of age-matched children. We also compared the food intake of GH-treated children (n=62) with randomized controls (n=26) after 1 year of GH treatment. In addition, we evaluated the effect of food intake and GH treatment on body composition and serum levels of IGF-I, IGFBP-3 and leptin. Our study shows that caloric intake, fat and carbohydrate intake of short SGA children aged 5.9 (1.6) years was significantly lower compared to the RDI for age-matched children. One year of GH treatment resulted in a significant increase of caloric, fat, carbohydrate and protein intake compared to baseline. Compared to randomized controls, caloric, carbohydrate and protein intake increased significantly after 1 year of GH treatment. Short SGA children had significantly lower SDS scores for LBM, fat mass, skinfold (SF) and BMI compared to age-matched references. They also had significantly lower serum IGF-I, IGFBP-3 and leptin levels. GH treatment resulted in a significant increase of height, LBM, BMI, IGF-I and IGFBP-3 SDS and a significant decrease of SF SDS and leptin SDS. In conclusion, our study shows that short SGA children have indeed a lower food intake than age-matched controls. During GH treatment the food intake increased significantly compared to baseline in contrast to the randomized control group.     

Effect of different growth hormone dosages on the growth velocity in children born small for gestational age

To assess whether short-term growth hormone (GH) treatment can improve the linear growth in children who were born small for gestational age (SGA), we started a randomized multicenter trial in 26 age- and sex-matched prepubertal children born SGA. During the 1st year of GH therapy, all children received GH 0.23 mg/kg/week, then during the 2nd year, 13 children received the same dose (group A), and in the other 13 children, the dose of GH was doubled, i.e., 0.46 mg/kg/week (group B). During the 1st year of therapy, the growth velocity significantly (p<0.0001) increased in all patients. During the 2nd year, group A showed a significant decrease of the growth velocity (p<0.015), whereas group B maintained the growth rate. The height in group A children significantly increased during the 1st and the 2nd year of GH therapy (p<0.000002 and p<0.000001, respectively), reaching the normal range in 8 out of 13 children at the end of 2 years of GH therapy. The height in group B children significantly increased during the 1st and the 2nd year of GH therapy (p<0.000001 and p<0.000001, respectively), reaching the normal range in all 11 children who completed the GH therapy. The height gain was similar in groups A and B treated with the same GH dosage during the 1st year of therapy. A greater increase in height gain was found in children of group B treated with the higher GH dosage during the 2nd year of therapy as compared with group A (p<0.02). Significant increases in insulin-like growth factor I (p<0.0001), acid-labile subunit (p<0.0002), and bone/chronological age ratio (p<0.0001) were found after the 1st year of GH therapy, but no significant changes were observed during the 2nd year, independently of the GH dose. In conclusion, the height velocity of children born SGA significantly increases during the 1st year of GH therapy, diminishes, but can decrease during the 2nd year, if the GH dosage is not raised.     

IGF-I and IGF binding protein-3 levels during initial GH dosage step-up are indicators of GH sensitivity in GH-deficient children and short children born small for gestational age

BACKGROUND: A stepwise increment of the GH dose is an approach aimed at avoiding adverse events. We investigated GH sensitivity by studying IGF-I and IGFBP-3 concentrations during the initial phase of GH treatment. METHODS: Our investigation was part of the regular follow-up of prepubertal children with GH deficiency (GHD) (n = 31) and small for gestational age (SGA) (n = 23). Dosage was increased in three steps: one-third at the start, two-thirds after 14 days, and the full dose after 28 days (full dose: GHD = 28 microg/kg body weight (BW)/day; SGA = 60 microg/kg BW/day). Blood samples were taken on days 0, 14 and 28, as well as in conjunction with anthropometrical examinations after 3, 6 and 12 months. IGF-I and IGFBP-3 were measured by means of published in-house RIAs and age-related references were used to calculate standard deviation scores (SDS). Height velocity (cm/year) and Delta HT SDS were taken as growth response parameters. RESULTS: Before GH treatment (GHD vs. SGA; median and p values): age (years) (6.6 vs. 6.0; n.s.), HT SDS (-2.6 vs. -3.2; p < 0.05); GH amount after stepping up (mug/kg BW/day) (28 vs. 60; p < 0.01); BW SDS (-0.5 vs. -2.9; p < 0.01); max. GH stimulated (microg/l) (5.6 vs. 10.8; p < 0.01); IGF-I SDS (-3.5 vs. -1.8; p < 0.01); IGFBP-3 SDS (-2.0 vs. 0.8; p < 0.01). After 1 year of GH therapy: HT velocity (cm/year) (9.8 vs. 9.6; n.s.), Delta HT SDS (0.9 vs. 0.9; n.s.); WT velocity (kg/year) (3.3 vs. 3.5; n.s.). Our results show that changes in growth similar to GHD could be induced in SGA by a dosage that was twice as high as the replacement dose given in GHD. GH dose and HT velocity did not correlate in both groups. IGF-I and IGFBP-3 increased as follows in GHD and SGA during stepping up of the dosage (ng/ml, GHD vs. SGA): at start, 54 vs. 89; at day 14, 78 vs. 132; at day 28, 90 vs. 167; at 3 months, 118 vs. 218. There was the same relationship between dose levels and absolute IGF-I concentrations in both groups. In terms of IGF-I SDS, the dose-response curve in SGA showed a shift to the right in comparison to GHD, thus indicating lower sensitivity to GH. The dynamics of IGF-I and IGFBP-3 differed, as IGFBP-3 peaked earlier (on day 28). In GHD, IGF-I SDS at 3 months was -0.7 vs. +0.9 in SGA. Near-identical levels were found for Delta IGF-I SDS and IGFBP-3 SDS above basal levels for each time-point investigated. First year HT velocity in GHD correlated negatively with basal IGF-I SDS (R(2) = 0.33; p <0.001) and basal IGFBP-3 (R(2) = 0.17; p <0.05) but did not correlate with the IGF-I increment during the 0- to 3-month period. Conversely, first year HT velocity correlated (+) in SGA with the IGF SDS increment during the 0- to 3-month period (R(2) = 0.26; p = <0.05). Height velocity in SGA, however, correlated neither with basal IGF-I and IGFBP-3 nor with the 0- to 3-month increments of IGFBP-3 SDS. CONCLUSIONS: IGFs increase during initial GH therapy, thus raising questions about short-term IGF generation tests. (I) In terms of IGF generation, substantially lower sensitivity to GH was observable in SGA. (II) Higher GH sensitivity during first year catch-up growth is associated with GHD, but in SGA it is attributable to increases in IGF. A wider range of GH dosages needs to be explored in order to gain further insight into the relationship between GH dose, IGF levels, and growth. Monitoring IGFs is a practical means for exploring GH sensitivity during dosage stepping up.     

Growth hormone treatment of short children born small for gestational age: a US perspective

Research during the last decade shows clearly that growth hormone (GH) therapy causes a sustained increase in growth velocity when applied to short children born small for gestational age (SGA). This occurs even though GH deficiency per se is an unlikely explanation for their lack of catch-up growth. In the United States, children born weighing less than -2 SD for gestational age and who show no growth recovery (usually defined as stature persisting below -2 SD at age 2 years) are eligible for GH treatment using doses up to 0.48 mg/kg per week. The management of these children brings new challenges to the pediatric endocrinologist. Intrauterine growth retardation reflects a variety of etiologies, some of which merit special consideration and may respond variably to GH. The dose of GH used exceeds physiologic replacement and is higher than that commonly used to treat other non-GH-deficient conditions such as Turner syndrome. Thus, what constitutes optimal therapy in terms of dose, timing and patient selection remains an important question. While GH therapy provides a means by which one aspect of the SGA syndrome can be helped, there are other issues for SGA apart from height. Future efforts should include studies that better define how GH should be used in the short child born SGA and address more broadly the medical, social and psychological needs of these patients.     

Physiological growth hormone secretion in children with short stature and intra-uterine growth retardation

31 prepubertal children with short stature [mean height standard deviation score (SDS) -2.84] and low birth weight (mean -2.82 SDS) were studied. Mean age was 6.0 years and mean height velocity SDS was -0.76. Patients were classified as having either the clinical characteristics of Russell-Silver syndrome (RSS) (4 F, 13 M) or not (4 F, 10 M). All children had an overnight profile of spontaneous growth hormone (GH) secretion. 4 children achieved a maximum GH concentration of less than 20 mU/l. 9 children with RSS secreted only one large GH peak during the night. Most of the non-RSS group had normal GH pulse frequency but 3 boys had a fast-frequency pattern. Abnormal GH secretion may contribute towards growth failure in children with low birth weight/RSS.     

Final height of growth hormone-treated GH-deficient children and girls with Turner's syndrome: the Dutch experience. The Dutch Advisory Group on Growth Hormone

In the Dutch growth hormone (GH) registration database there are currently 552 GH-deficient children being treated, subcutaneously, with recombinant human GH six to seven times per week. Of those, 112 who have been treated for at least 2 years have reached final height. Mean age at start of therapy was 11.70 years. Mean GH dose was 15.5 IU/m(2) body surface per week. Mean final height was 173.2 cm (boys) and 159.7 cm (girls) and -1.36 SD of the population mean. Of the patients, 73.2% and 63.4%, respectively, reached a final height above -2 SD of the population or within target limits. FH-SDS was higher compared with the results of earlier cohorts with different treatment regimens. Target height, GH peak value at diagnosis, age at start of GH therapy, height SDS (HSDS) at start of puberty, and duration of GH therapy were significantly correlated with final height. These results, combined with those of a prospective GH dose-response study, suggest that better long-term results can be obtained with early and prolonged treatment and if the GH dose is individually adapted to the short-term growth response. In an ongoing dose-response study, 68 girls with Turner's syndrome, aged 2-11 years, were randomized into three dosage groups with a daily GH dose of: (group A) 4 IU/m(2) body surface; (group B) 4 IU/m(2) in the first year of therapy and 6 IU/m(2) thereafter; (group C) 4 IU/m(2) in the first year, 6 IU/m(2) in the second year, and 8 IU/m(2) thereafter. After 4 years of GH therapy, girls aged 12 years or older started low-dose oestrogen therapy. After 7 years of GH therapy, mean HSDS in all three groups had increased to values above the third percentile for healthy girls. Mean final height and final height gain of 25 girls was 159.1 and 12.5 cm, 161.8 and 14.6 cm, and 162.7 and 16.0 cm in groups A, B and C respectively. These long-term and final height results are more favourable than the results of earlier Dutch Turner's syndrome studies. Possible explanations are the higher GH doses and/or the younger age at start of GH therapy.     

Bone age progression during the first year of growth hormone therapy in pre-pubertal children with idiopathic growth hormone deficiency, Turner syndrome or idiopathic short stature, and in short children born small for gestational age: analysis of data from KIGS (Pfizer International Growth Database)

BACKGROUND/AIMS: The beneficial effects of growth hormone (GH) therapy on statural growth in children are well established, but the effects on skeletal maturation are less clear. The progression of bone age (BA) was therefore studied during the first year of GH treatment in pre-pubertal children with idiopathic GH deficiency (GHD), Turner syndrome (TS) or idiopathic short stature (ISS), and in short pre-pubertal children born small for gestational age (SGA). METHODS: Cross-sectional data on 2,209 short children with idiopathic GHD, 694 with TS, 569 with ISS and 153 with SGA were analysed. Longitudinal data were also analysed from 308 children with idiopathic GHD, 99 with TS, 57 with ISS and 29 with SGA. All patients included in the study were enrolled in KIGS (Pfizer International Growth Database) and were being treated with recombinant human GH (Genotropin). BA was assessed using the Greulich and Pyle method at baseline and after 1 year of GH therapy. RESULTS: In all groups of patients the mean progression of BA was 1 year during the year of GH therapy, although there was considerable individual variation. Progression of BA was not correlated with chronological age, BA, height SD score (SDS) or body mass index SDS at the onset of GH therapy. There was also no consistent effect of the GH dose on BA progression. CONCLUSION: Progression of BA appears to be normal in patients receiving GH in these diagnostic groups, at least over the first year of treatment in pre-puberty.     

Depression,smoking, physical inactivity and season independently associated with midnight salivary cortisol in type 1 diabetes

Background

Trisomy 9p is an uncommon anomaly characterised by mental retardation, head and facial abnormalities, congenital heart defects, kidney abnormalities, and skeletal malformations. Affected children may also show growth and puberty retardation with delayed bone age. Auxological and endocrinological data are lacking for this syndrome.

Methods

We describe three girls and one boy with 9p trisomy showing substantial growth failure, and we evaluate the main causes of their short stature.

Results

The target height was normal in all families, ranging from 0.1 and -1.2 standard deviation scores (SDS). The patients had a low birth-weight (from -1.2 to -2.4 SDS), birth length (from -1.1 to -3.2 SDS), and head circumference (from -0.5 to -1.6 SDS). All patients presented with substantial growth (height) retardation at the time of 9p trisomy diagnosis (from -3.0 to -3.8 SDS). The growth hormone stimulation test revealed a classic growth hormone (GH) deficiency (GHD) in patients 1, 3, and 4. In contrast, patient 2 was determined to have a GH neurosecretory dysfunction (GHNSD). The plasma concentrations of IGF-I and IGFBP-3 were low in all patients for their ages and sexes (from -2.0 to -3.4 SDS, and from -1.9 to -2.8 SDS, respectively). The auxological follow-up showed that those patients who underwent rhGH treatment exhibited a very good response to the GH therapy, whereas patients 3 and 4, whose families chose not to use rhGH treatment, did not experience any significant catch-up growth.

Conclusions

GH deficiency appears to be a possible feature of patients with 9p trisomy syndrome. These patients, particularly those with growth delays, should be evaluated for GH secretion.