Growth hormone treatment in Turner syndrome accelerates growth and skeletal maturation. Dutch Growth Hormone Working Group

The GH/IGF-1 system in critical illness

The Growth Hormone and Insulin-like Growth Factor-1 (IGF-1) axis plays a pivotal role in critical illness, with a derangement leading to profound changes in metabolism. Protein wasting with skeletal muscle loss, delayed wound healing, and impaired recovery of organ systems are some of the most feared consequences. The use of human recombinant Growth Hormone (rhGH) and Insulin-like Growth Factor-1 (IGF-1) - alone and in combination - has been studied extensively in preclinical and clinical trials. This article reviews the current knowlegde and clinical practice of the use of rhGh and IGF-1 in critically ill patients, with a special focus on the trauma and burns patient population.

Randomized controlled trial to determine the efficacy of long-term growth hormone treatment in severely burned children

BACKGROUND

Recovery from a massive burn is characterized by catabolic and hypermetabolic responses that persist up to 2 years and impair rehabilitation and reintegration. The objective of this study was to determine the effects of long-term treatment with recombinant human growth hormone (rhGH) on growth, hypermetabolism, body composition, bone metabolism, cardiac work, and scarring in a large prospective randomized single-center controlled clinical trial in pediatric patients with massive burns.

PATIENTS AND METHODS

A total of 205 pediatric patients with massive burns over 40% total body surface area were prospectively enrolled between 1998 and 2007 (clinicaltrials.gov ID NCT00675714). Patients were randomized to receive either placebo (n = 94) or long-term rhGH at 0.05, 0.1, or 0.2 mg/kg/d (n = 101). Changes in weight, body composition, bone metabolism, cardiac output, resting energy expenditure, hormones, and scar development were measured at patient discharge and at 6, 9, 12, 18, and 24 months postburn. Statistical analysis used Tukey t test or ANOVA followed by Bonferroni correction. Significance was accepted at P < 0.05.

RESULTS

RhGH administration markedly improved growth and lean body mass, whereas hypermetabolism was significantly attenuated. Serum growth hormone, insulin-like growth factor-I, and IGFBP-3 was significantly increased, whereas percent body fat content significantly decreased when compared with placebo, P < 0.05. A subset analysis revealed most lean body mass gain in the 0.2 mg/kg group, P < 0.05. Bone mineral content showed an unexpected decrease in the 0.2 mg/kg group, along with a decrease in PTH and increase in osteocalcin levels, P < 0.05. Resting energy expenditure improved with rhGH administration, most markedly in the 0.1 mg/kg/d rhGH group, P < 0.05. Cardiac output was decreased at 12 and 18 months postburn in the rhGH group. Long-term administration of 0.1 and 0.2 mg/kg/d rhGH significantly improved scarring at 12 months postburn, P < 0.05.

CONCLUSION

This large prospective clinical trial showed that long-term treatment with rhGH effectively enhances recovery of severely burned pediatric patients.

Turner syndrome: searching for better outcomes

OBJECTIVES

To assess the results of growth hormone on the growth of girls with Turner Syndrome and identify relevant parameters to improve outcomes.

METHODS

Growth velocity and final height were studied in a historical cohort of 41 girls, regularly followed up for hormone distribution at three referral centers. The influence of oxandrolone and of estrogens on the final height was analyzed. The girls (initial chronological age=8.9+/-3.4years; initial bone age=7.0+/-3.1years) used 0.19 mg/kg/week of growth hormone for 4.0 +/- 2.0 years.

RESULTS

In the first year, growth velocity increased by 71.5% in 41 girls and 103.4% in those who reached final height (11 girls). The whole group had a gain in the height SDS of 0.8 +/- 0.7 (p<0.01) and for those who reached a final height of 1.0 +/- 0.8 (p<0.01). Final height (143.6 +/-6.3 cm) was 3.9 +/- 5.3 cm higher than the predicted height, and the height gain occurred before estrogen therapy. Oxandrolone had no significant influence on height gain. The significant variables contributing to the final height were the duration of growth hormone used and its use prior to starting estrogens, the initial height SDS, and the growth velocity during the first year of treatment.

CONCLUSIONS

We concluded that the use of growth hormone significantly increased the final height, which remained lower than the target. Results point to a need for starting growth hormone use as early as possible and to maximize treatment before estrogen replacement. It has been observed that even moderate doses of growth hormone may significantly increase early growth velocity.

Beneficial effects of extended growth hormone treatment after hospital discharge in pediatric burn patients

OBJECTIVE

To study the efficacy of growth hormone given to severely burned children from discharge to 12 months after burn and for 12 months after the drug was discontinued.

SUMMARY BACKGROUND DATA

We have previously shown that low-dose recombinant human growth hormone (rhGH), given to children after a severe thermal injury, successfully improved lean muscle mass, bone mineral content, and growth. The aim of the present study was to investigate long-term functional improvements after treatment.

METHODS

Forty-four pediatric patients with over 40% total body surface area burns were studied for 24 months after burn. Patients were randomized to receive either rhGH (0.05 mg/kg body weight) or placebo. Height, weight, body composition, serum hormones, resting energy expenditure, cardiac function, muscle strength, and number of reconstructive procedures performed were measured during rhGH treatment and for 12 months after treatment was discontinued. Statistical analysis used Tukey's multiple comparison test. Significance was accepted at P < 0.05.

RESULTS

Height, weight, lean body mass, bone mineral content, cardiac function, and muscle strength significantly improved during rhGH treatment compared with placebo (P < 0.05). This treatment significantly increased GH, IGF-I, and IGFBP-3, whereas serum cortisol decreased (P < 0.05). The number of operative reconstructive procedures was significantly lower with rhGH (P < 0.05). Improvements in height, bone mineral content, and IGF-1 concentrations persisted after rhGH treatment (P < 0.05). No side effects with rhGH were observed.

CONCLUSIONS

Administration of rhGH for 1 year after burn was safe and improved recovery. These salutary effects continued after rhGH treatment was discontinued.

Effects of growth hormone on anthropometric measurements and cardiac function in children with thermal injury

Severe burn injuries are associated with growth delays a persistent hypermetabolic response and severe muscle catabolism and wasting. Growth hormone (GH), a potent anabolic agent and salutary modulator of post-traumatic metabolic responses has been shown to decrease muscle wasting, improve net protein synthesis and attenuate growth delays in burned children. In non-burned populations, GH has recently been shown to be of benefit in enhancing cardiac performance and improving cardiac contractility and efficiency. Yet, whether administration of GH will induce similar improvements in cardiac function in severely burned children is presently unknown. We therefore, investigated whether the administration of GH initiated upon hospital discharge (95% healed) and continued for 1-year post-burn would improve resting cardiac function in burned children. Severely burned children were randomized to receive either saline placebo (n = 37) or 0.05 mg/kg per day of GH (n = 39) from discharge until 12-month post-burn. Outcome variables included height, weight, lean body mass, resting energy expenditure, cardiac index, stroke-volume index, heart rate and left ventricular ejection fraction.

RESULTS

height, weight, lean body mass and ejection fraction showed a significant increase with GH. Our results indicate that severely burned children treated with long-term GH show a significant improvement in left ventricular ejection fraction.

Effects of exogenous growth hormone on resting pulmonary function in children with thermal injury

Burned children living beyond the acute phase of injury often have extensive physical functional limitations, such as impaired spirometry pulmonary function (PF). In patients with both lung disease and nutritional compromise, such as cystic fibrosis, studies suggest that growth hormone (GH) therapy improves PF. However, whether GH will improve PF in burned children is presently unknown. We therefore evaluated whether GH administration of 0.05 mg/kg/day for 1 year would improve PF in burned children. Thirty children, aged 7 to 18, with a 40% or more total body surface area burned were randomized into two groups and studied. One group received GH (n = 17) and the other received saline (n = 13). No differences were noted at hospital discharge between groups in age, % total body surface area, height, and weight. At 12 months after burn, both groups had similar height and weight. Baseline PF were below normal in both groups, but no statistical differences were noted between groups. At 1 year, there was a significant increase in PF in both groups; however, this increase in PF was similar in both groups. We conclude that the response in PF in burned children from the administration of GH prescribed for up to 1 year is limited.

Effect of exogenous growth hormone and exercise on lean mass and muscle function in children with burns

We tested the hypothesis that the administration of recombinant human growth hormone (rHGH) and exercise would increase lean body mass (LBM) and muscle strength in burned children to a greater extent than rHGH or exercise separately. Children, ages 7-17 yr, with >40% body surface area burned, were randomized into groups. One group (GHEX, n = 10) participated in a 12-wk in-hospital physical rehabilitation program supplemented with an exercise program and received 0.05 mg. kg(-1). day(-1) of rHGH. A second exercising group (SALEX, n = 13) received saline. A third group (GH, n = 10) received a similar dose of rHGH as GHEX and participated in a 12-wk, home-based physical rehabilitation program without exercise. The fourth group (Saline, n = 11) received saline and participated in a 12-wk, home-based physical rehabilitation program without exercise. The mean (+/-SE) percent change in lean body mass after 12 wk was not significantly different between GHEX (9.0 +/- 2.1%), SALEX (5.4 +/- 1.6%), and GH (5.8 +/- 1.8%) groups (P = 0.33). However, the mean percent change in muscle strength was significantly greater in the GHEX (36.2 +/- 5.4%) and SALEX (42.6 +/- 10.0%) groups than in the GH (-7.4 +/- 4.7%) or Saline (6.7 +/- 4.4%) groups (P = 0.008). In summary, rHGH GHEX, SALEX, and GH alone produced similar improvements in LBM. However, muscle strength was only increased via exercise.

Attenuation of posttraumatic muscle catabolism and osteopenia by long-term growth hormone therapy

OBJECTIVE

To determine whether the beneficial effects of growth hormone persist throughout the prolonged hypermetabolic and hypercatabolic response to severe burn.

SUMMARY BACKGROUND DATA

The hypermetabolic response to severe burn is associated with increased energy expenditure, insulin resistance, immunodeficiency, and whole body catabolism that persists for months after injury. Growth hormone is a potent anabolic agent and salutary modulator of posttraumatic metabolic responses.

METHODS

Seventy-two severely burned children were enrolled in a placebo-controlled double-blind trial investigating the effects of growth hormone (0.05 mg/kg per day) on muscle accretion and bone growth. Drug or placebo treatment began on discharge from the intensive care unit and continued for 1 year after burn. Total body weight, height, dual-energy x-ray absorptiometry, indirect calorimetry, and hormone values were measured at discharge, then at 6 months, 9 months, and 12 months after burn. Results were compared between groups.

RESULTS

Growth hormone subjects gained more weight than placebo subjects at the 9-month study point; this disparity in weight gain continued to expand throughout the remainder of the study. Height also increased in the growth hormone group compared with controls at 12 months. Change in lean body mass was greater in those treated with growth hormone at 6, 9, and 12 months. Bone mineral content was increased at 9 and 12 months; this was associated with higher parathormone levels.

CONCLUSIONS

Low-dose recombinant human growth hormone successfully abates muscle catabolism and osteopenia induced by severe burn.

Near normalization of final height with adapted doses of growth hormone in Turner's syndrome

An adapted GH dose regimen was evaluated in 14 untreated patients with Turner's syndrome. The initial GH dose (0.7 U/kg.BW) was increased by 0.7 U/kg.BW, up to a maximum of 2.1 U/kg.BW, when growth velocity (GV) declined to less than 200% of the pretreatment level. These patients were compared to a group of 17 patients with similar initial characteristics, who received a fixed dose of 0.9 U/kg.BW GH. Tolerance to both GH regimens was excellent. The adapted GH doses only partially prevented the waning effect observed with conventional doses of GH, and the initial goal of doubling GV was only achieved in 42% of the 112 patient-semesters. Doubling the GH dose from 0.7 to 1.4 U/kg.BW increased the GV by 1.6 +/- 1.8 cm/yr (P < 0.006); increasing the GH dose from 1.4 to 2.1 U/kg.BW increased GV by 0.8 +/- 1.3 cm/yr (P = NS). The overall height gain during the 4-yr trial was 25.6 +/- 3.9 cm in the adapted dose group and 21.8 +/- 3.9 cm in the conventional group (P < 0.02). Final height (FH) results were obtained in 12 of 14 patients in the adapted dose group and all 17 patients in the conventional group and compared to the predicted FH using Lyon's method. The estimated height benefit was 10.6 +/- 3.8 cm in the adapted dose group compared to 5.2 +/- 3.7 cm in the conventional group (P < 0.01). Eighty-three percent of the patients in the adapted dose group had an FH superior or equal to -2 SD score for the general population compared to 29% in the conventional group. In conclusion, a marked increment in the GH dose in girls with Turner's syndrome associated with a relatively late age at introduction of estrogen therapy brought 83% of the patients into the lower range of the normal height distribution of the general population.

[Turner syndrome: spontaneous growth of stature, weight increase and accelerated bone maturation]

BACKGROUND

Since growth hormone is effective in increasing the height of girls with Turner's syndrome, it is important to dispose of growth and bone maturation curves in a large number of untreated patients.

POPULATION AND METHODS

Data on growth and bone maturation were collected from 160 patients with Turner's syndrome (50 have reached final height), born 1965-1991, untreated with growth hormone or anabolic steroids. X monosomy was found in half of the patients, mosaicism or X abnormality was present in the other half. Spontaneous puberty occurred in 25% (n = 25) of patients older than 13 years, 38 patients received estrogen after 13 years. Final heights were compared to predicted height according to Lyon's method.

RESULTS

Forty-five percent of patients were small for date. Height velocity decreased from 2 years of age and decreased faster during adolescence, when gonadal dysgenesis occurred. Bone maturation velocity decreased also during adolescence. Excessive weight appeared after the age of 5 years. Patients with partial deletion of the long arm of X (n = 6) were taller than the other girls (n = 44) (mean +/- DS) 152.5 +/- 3.1 cm, range 150-158 cm versus 142.5 +/- 4.9 cm, 130-150 cm (P < 0.0001). Final height was not modified by spontaneous puberty. Final height was correlated with birth weight (r = 0.7), maternal height (r = 0.5) and mid parental height (r = 0.5). Finally, the Lyon's method for predicted final height seemed to be suitable for this population, (r = 0.8, P < 0.001).

CONCLUSION

Appropriate growth curve is an essential clinical tool in evaluating treatment aimed at increasing final stature in patients with Turner's syndrome.

Guidelines for the use of growth hormone in children with short stature. A report by the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society

On the basis of the information currently available, the only conditions in which GH therapy appears to be safe and effective in increasing adult height are GH deficiency and, likely, Turner syndrome. Therapy with GH also increases the growth velocity of children with CRI and may increase adult height, but no long-term data are available. Encouraging short-term results have been reported in patients with a few other conditions, such as patients with glucocorticoid-induced growth failure, renal transplantation, and Prader-Willi syndrome, but the data are limited and no long-term studies have been reported; in many other conditions the data are either inconclusive or discouraging. For children in these latter groups, GH therapy should be considered investigational and undertaken only as part of ethically sound, controlled clinical trials. Knowledge concerning the conditions in which GH is safe and effective is a prerequisite to making rational decisions concerning its use. However, in deciding whether therapy is warranted in an individual child, one must consider other important factors. The age and emotional maturity of the child, the family structure and dynamics, and even financial considerations may, in some cases, outweigh the presence of a GH-responsive condition. Likewise, the child's and the family's views about "short" stature and the likely benefits of therapy must be considered. Ultimately, a decision concerning the appropriateness of GH therapy must be individualized and based on a realistic assessment of its impact on the quality of life of the child and future adult.

Final height after long-term growth hormone treatment in Turner syndrome. European Study Group

OBJECTIVES

To study final height after long-term growth hormone (GH) treatment in girls with Turner syndrome (TS).

PATIENTS

One hundred fifty three patients with TS, participating in five European trials, were included. They started GH treatment in 1987-1989 at an age of 10 years or older. Mean age at start of treatment ranged between 11.7 and 14.6 years among countries and mean bone age between 9.4 and 11.8 years. Fourteen girls were lost to follow-up, leaving 139 for analysis. Most girls have now attained final height (FH), defined as a linear growth velocity (GV) of 4 mm/yr or less, measured over at least 6 months (group 1, n = 56), or near-FH, defined as a GV of 5 to 9 mm/yr (group 2, n = 22). Sixty-one girls were still growing 10 mm/yr or more.

METHODS AND MAIN RESULTS

At the last measurement, mean (SD) height was 150.7 (4.9) cm in group 1 and 148.5 (5.1) cm in group 2. The differences between FH and projected final height based on extrapolation of the initial height-standard deviation score on Turner syndrome reference values, were 2.9 (3.8) and 3.0 (3.3) cm, respectively. The mean gain over the Bayley-Pinneau prediction of FH was 3.3 (3.9) cm in both groups. No significant differences between countries were found. The range of gains over projected height (-4.7 to 12.1 cm) was large, and 25% of gains were 5 cm or more. Gain over initial projection was strongly related to initial growth delay and to growth response during the first 2 years of treatment. A logistic regression model is presented that predicts gain of more than 5 cm with a positive predictive value of 62% and a negative predictive value of 84%.

CONCLUSIONS

Long-term GH treatment in girls with TS, starting treatment at a relatively advanced age ( > 10 years) resulted in a modest mean gain in FH of 3 cm, with wide interindividual variation.

Treatment of patients with Ullrich-Turner syndrome with conventional doses of growth hormone and the combination with testosterone or oxandrolone: effect on growth, IGF-I and IGFBP-3 concentrations

Thirty-nine girls with Ullrich-Turner syndrome (UTS) (median age 9.5 years) were treated with growth hormone (GH) with either 12 or 18 IU/m2 per week for 12 months followed by combination therapy with either oxandrolone (Ox) (0.0625 mg/kg/day po) or low-dose testosterone (T) (5 mg in every 2 weeks). Growth velocity improved significantly after 12 IU/m2 per week (6.4 +/- 1.7 cm/year vs 4.0 +/- 1.3 cm/year, x +/- SD, P < 0.001) and 18 IU/m2 per week of GH (6.5 +/- 1.3 cm/year vs 4.5 +/- 1.4 cm/year, P < 0.001). Ox, but not T was effective in maintaining growth velocity during the 2nd year of therapy (6.9 +/- 1.3 vs 5.3 +/- 1.5 cm/year). Basal insulin-like growth factor-I (IGF-I) concentrations were in the lower normal range and increased significantly in patients treated with 18 IU/m2 per week (357 +/- 180 ng/ml vs 160 +/- 84 ng/ml) and 12 IU/m2 per week (273 +/- 121 ng/ml vs 140 +/- 77 ng/ml). IGF-I concentrations increased further after addition of Ox (533 +/- 124 ng/ml, P < 0.001) or T (458 +/- 158, P < 0.05). IGFBP-3 concentrations were in the upper normal range before therapy and increased only moderately in both GH dosage groups. However, IGF binding protein-3 (IGFBP-3) concentrations were not affected by additional Ox or T treatment.

CONCLUSIONS

1. Conventional GH doses are effective in increasing growth velocity in UTS, especially, when combined with Ox.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term results of growth hormone therapy in children with short stature, subnormal growth rate and normal growth hormone response to secretagogues. Dutch Growth Hormone Working Group

BACKGROUND AND OBJECTIVE

Growth hormone treatment in children with idiopathic short stature (ISS) leads to growth acceleration in the first years, but the effect on final height is still poorly documented. We therefore studied the long-term effect of GH therapy in children with idiopathic short stature.

DESIGN

We have treated 27 prepubertal children with ISS with recombinant human GH (rhGH) in an initial dosage of 2 IU/m2 body surface/day subcutaneously, which was doubled either after the first year if the height velocity increment was less than 2 cm/year, or thereafter if height velocity fell below the P50 for bone age. Growth and bone maturation of the treatment group (ISS group, n = 21) were compared to those of an untreated control group with ISS (ISS controls, n = 27) and of a group of rhGH treated children with isolated GH deficiency (GHD group, n = 7).

RESULTS

In 9 patients of the ISS group still on treatment, height standard deviation score (HSDS) for chronological age increased from -3.8 +/- 0.7 to -2.3 +/- 0.9 (mean +/- standard deviation) over 6 years, while in matched ISS controls HSDS for age did not change. HSDS for age in the GHD group increased from -3.9 +/- 0.6 to -1.8 +/- 0.7 after 4 years, significantly more than the ISS group. Bone maturation was accelerated in the ISS and GHD groups. HSDS for bone age and predicted adult height did not change in either group. Final height in 12 children of the ISS group was -2.6 +/- 1.0 SDS. In the untreated controls final height was similar. A low integrated GH concentration over 24 hours, a low GH peak to provocative stimuli, and minimal initial BA delay predicted a favourable outcome.

CONCLUSION

rhGH treatment in this group of children with idiopathic short stature did not increase average final height. Part of the heterogeneity of the response can be attributed to the variation in endogenous GH secretion and initial bone age delay.

Turner syndrome: final height, glucose tolerance, bone density and psychosocial status in 25 adult patients

The information available on the medical and psychosocial status of patients with Turner syndrome beyond the paediatric age group is scarce. We therefore studied 25 unselected women with cytogenetically proven Turner syndrome (age 20-50 years), who never received any growth-promoting therapy, and ten control women (25-48 years). In addition to anthropometric measurements, an oral glucose tolerance test was performed, auto-antibodies to endocrine tissues were studied, bone mineral density of the forearm was measured by single photon densitometry, and information about the psychosocial distress of the patients was obtained. Adult height averaged 148.7 +/- 1.1 cm (mean +/- SE), which was 16 cm below the mean of adult women from a similar background. In Turner patients, final height correlated significantly with mid-parental height (final height = 0.67 x MPH + 32.1; r = 0.69). Body mass index was increased in Turner patients (25.6 +/- 1.3 kg/m2) compared to controls (21.4 +/- 0.6; P < 0.006). Six patients (25%) had impaired glucose tolerance or overt diabetes mellitus (one patient). Insulin release was augmented but delayed in the Turner group, and the area under the insulin stimulation curve was correlated to body mass index (r = +0.54, P < 0.01). Thyroid antibodies were detected in nine patients (37.5%). On average, bone density of the forearm was only marginally reduced compared to the age-dependent normal range. All women were employed, while only one of the Turner women was married. As a group, the subjects expressed greater distress due to infertility compared to short stature.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of spontaneous or induced puberty on the growth promoting effect of treatment with growth hormone in girls with Turner's syndrome

OBJECTIVE

The aim was to evaluate the effect of 3 years treatment with recombinant human growth hormone (rhGH) on height velocity and height in girls with Turner's syndrome (TS) and to study to influence of spontaneous or induced puberty on the growth promoting effect of rhGH.

PATIENTS AND DESIGN

The investigation was performed in 36 girls with Turner's syndrome treated for 3 years with rhGH in a dose of 1 IU/kg week, administered as daily subcutaneous injections. Fifteen patients remained prepubertal throughout the observation period (Group 1). During the first 2 years of rhGH therapy, four girls developed puberty spontaneously (Group 2). During the 3rd year of rhGH treatment puberty was induced with 100 ng/kg day ethinyl oestradiol orally in 17 girls requesting pubertal development and with a bone age of at least 11 'years' (Group 3).

RESULTS

During the first year of rhGH therapy height velocity increased significantly in all patients. Mean +/- SD height velocity was higher in the four patients with Turner's syndrome who developed spontaneous puberty than in 17 age-matched girls with Turner's syndrome without puberty (8.9 +/- 1.2 vs 7.4 +/- 1.2 cm/year; P < 0.05). During the second and third year of rhGH treatment height velocity decreased in all patients but remained above baseline levels. The induction of puberty with 100 ng/kg day ethinyl oestradiol in the patients of Group 3 did not lead to an acceleration of height velocity, but seemed in contrast to decelerate height velocity. After 3 years of rhGH treatment, 21 out of 36 patients have obtained a height at or above the initially calculated projected adult height and five girls are already taller than 150 cm.

CONCLUSIONS

The onset of spontaneous puberty during the first years of rhGH treatment seems to have an additive effect to rhGH on height velocity. Induction of puberty with oral administration of 100 ng/kg day ethinyl oestradiol did not have any beneficial effect on height velocity and seems therefore not to be the optimal way to induce puberty with an adequate pubertal growth spurt in girls with Turner's syndrome under rhGH therapy. Different doses and routes of oestrogen administration have to be evaluated in order to mimic the growth promoting effect of spontaneous puberty as well as possible.