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.     

Growth during and after a trial of growth hormone releasing hormone 1-29 in children with idiopathic short stature or growth hormone neurosecretory dysfunction

The growth promoting effects of once nightly subcutaneous injections of growth hormone releasing hormone (GHRH) 1-29 (30 microg/kg) for 6 months were studied in 16 slowly growing prepubertal children with idiopathic short stature (ISS; Group 1) and 8 similar children with growth hormone neurosecretory dysfunction (GHND; Group 2). Each child underwent endogenous growth hormone evaluation using both pharmacological and physiological testing; each had stimulated values > 10 microg/l and were subsequently placed into one of two groups based on pooled 12-hour overnight GH of < or > or = 3 microg/l. Each patient was followed every three months for one year. There were no significant differences in the two groups throughout the study with the exception of the endogenous GH levels. Both groups responded to GHRH therapy with similar significant increases in their rates of growth. Although a subset of patients (6 of 21) continued to grow at a rate significantly greater than the pre-therapy rate of growth, overall rates of growth were not significantly different from the pre-therapy growth rates 6 months following the discontinuation of GHRH treatment. We conclude that GHRH 1-29, given in the doses provided, leads to similar changes in growth rates in short, slowly growing children who are GH sufficient and those with GHND. Despite prior reports to the contrary, GHND patients do not experience a sustained increased in growth rate upon discontinuation of GHRH.     

Estimated cost-effectiveness of growth hormone therapy for idiopathic short stature

OBJECTIVE: To estimate the cost-effectiveness of growth hormone (GH) therapy for idiopathic short stature (ISS). DESIGN: Cost-effectiveness analysis. SETTING: Decision model. PATIENTS: A cohort of 10-year-old prepubertal boys with ISS treated with GH. INTERVENTIONS: Comparison of children treated for 5 years with GH therapy vs children receiving no intervention. MAIN OUTCOME MEASURES: Incremental cost per child, incremental growth per child, and incremental cost per inch of final height gain. RESULTS: The estimated incremental cost-effectiveness ratio of GH therapy for ISS in the base case analysis compared with no therapy was 52,634 dollars per inch (per 2.54 cm), or 99,959 dollars per child, reflecting an incremental growth of 1.9 in (4.8 cm). Alternate treatment strategies such as increased duration of GH treatment and high pubertal dosing of GH did not substantially improve the cost-effectiveness ratio. Probabilistic sensitivity analyses showed that growth variability in response to GH had the greatest impact on the cost-effectiveness of GH therapy. CONCLUSIONS: Targeted treatment of children with ISS with the greatest potential for growth appears critical for maximizing cost-effectiveness of GH treatment. However, the significance of the cost per inch is difficult to judge until the utility gains associated with height gain after GH therapy for ISS can be ascertained.     

Partial growth hormone insensitivity - idiopathic short stature is not always idiopathic

Saenger P. Partial growth hormone insensitivity - idiopathic short stature is not always idiopathic. Acta Pædiatr 1999; Suppl 428: 194–8. Stockholm. ISSN 0803–5326
Heterozygous growth hormone receptor (GHR) gene defects are not a common cause of idiopathic short stature. Although some of these GHR mutations may result in relative insensitivity to growth hormone (GH) in other studies, obligate heterozygotes did not present any clinical manifestations. Although patients with GH insensitivity and elevated GH binding protein (GHBP) levels have been described, it may be a reasonable approach to screen children who have growth failure, low levels of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3, and low levels of GHBP. Whether the sensitivity of this screening approach can be increased by administering pharmacological doses of GH for a few days and measuring the resultant increase in serum IGF-I concentration remains to be determined by ongoing studies. □ Growth hormone insensitivity, growth hormone receptor, short stature     

Partial growth hormone insensitivity--idiopathic short stature is not always idiopathic

Heterozygous growth hormone receptor (GHR) gene defects are not a common cause of idiopathic short stature. Although some of these GHR mutations may result in relative insensitivity to growth hormone (GH) in other studies, obligate heterozygotes did not present any clinical manifestations. Although patients with GH insensitivity and elevated GH binding protein (GHBP) levels have been described, it may be a reasonable approach to screen children who have growth failure, low levels of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3, and low levels of GHBP. Whether the sensitivity of this screening approach can be increased by administering pharmacological doses of GH for a few days and measuring the resultant increase in serum IGF-I concentration remains to be determined by ongoing studies.     

Growth hormone releasing hormone and growth hormone: genetic studies in familial growth hormone deficiency

Four families with growth hormone (GH) deficiency, either isolated or with other pituitary hormonal deficits are described. Members of each underwent pharmacological testing for GH secretion and infusions of GH releasing hormone (GHRH) to determine the locus of the defect in GH secretion. In addition, we have extracted DNA from white blood cells to characterize the GHRH and GH genes. All members tested had the normal complement of GH and GHRH genes. Four generations of one family with isolated GH deficiency, autosomal dominant were studied. The younger members showed minimal GH responsiveness to a single infusion of GHRH. However, the older members did not respond even after 30 doses of GHRH given intravenously every 3 h. Two members of a family with the autosomal recessive type of isolated GH deficiency had large GH increases after GHRH infusion. Thus in these families the GH secretory defect lies within the hypothalamus. Members of two families with pituitary deficiency (GH and other tropic hormones) of the autosomal recessive type had variable responses to GHRH and varying amounts of pituitary tissue seen on high resolution CT scans. Although it is not possible to delineate the precise location of the secretory defects in these latter two families, a hypothalamic defect is probable based on the responses to multiple trophic stimuli. Heterogeneity of structure and function exists within and between families with isolated GH deficiency and within and among families with pituitary deficiency. It is from the study of such families in which all members presumably have the same underlying defect that one can more readily decide on a pathogenetic mechanism.     

Growth hormone therapy in short stature

Unlimited availability of growth hormone (GH), and the demonstration of increased growth velocity (GV) during GH treatment in non-GH-deficient children have suggested new indications for GH therapy in short stature. There are two principle conditions with GH-related short stature: classical growth hormone deficiency (CGHD) and growth hormone neurosecretory dysfunction (GHND). Present knowledge about the effects of GH treatment in these and other disorders of short stature are reviewed. In non-CGHD, it is not possible to predict the short-term effect on growth during GH therapy, and even if GV increases, the effect on final adult height remains to be documented. This, together with potential side effects and the high expense of GH treatment, exhort to a restricted attitude towards routine GH treatment of short children without GH deficiency.     

Adult height in children with idiopathic short stature treated with growth hormone

Idiopathic short stature (ISS) includes a heterogeneous group of patients with common characteristics to those of familial short stature and constitutional delay. Some authors state that these children can often respond to GH treatment, thus increasing their adult height. The aims of this study were to determine the effect of GH treatment (0.5-0.7 IU/kg/week) and the influence of some initial variables on adult height in patients with ISS. It was a non-randomized, observational study of 30 boys with ISS and a historical control group of 42 patients. The patients were followed until achieving their adult height. The mean height gain of the treated group attributable to GH was 4.5 cm. A stepwise regression model considering predicted adult height and target height as independent variables and final height as dependent variable gave an R2 coefficient of 0.38. We conclude that GH significantly increases final height in boys with ISS.     

Growth hormone therapy of short stature

Considerable progress has been made in the diagnosis and treatment of growth hormone-related short stature. Knowledge about growth hormone releasing factor (GRF) and somatomedin C has provided the possibility of distinguishing between hypothalamic and pituitary growth hormone deficiency and growth hormone resistance. It has been shown that treatment with GRF may stimulate growth in certain cases of growth hormone deficiency. Recombinant DNA techniques may, in the near future, provide sufficient amounts of GRF, growth hormone and possibly somatomedin C for clinical use. At present, many countries have prohibited the use of human pituitary growth hormone due to a possible risk of transmission of Creutzfeldt-Jakob disease. It has become increasingly clear that several short children without classical growth hormone deficiency, may increase their growth velocity during growth hormone treatment. There are many medical, psychological, ethical and economical implications involved in the extended treatment of children with short stature. It is necessary to maintain a restricted approach towards the treatment of children with short stature, and such treatment should be prescribed and controlled by a limited number of well-trained paediatric endocrinologists. This article reviews some of the present knowledge in this rapid developing field of paediatric endocrinology.     

Long-term treatment with growth hormone of children with short stature and normal growth hormone secretion.

Children with short stature but normal growth rate and/or normal growth hormone response to sleep and secretagogues were treated with recombinant methionyl human growth hormone, 0.3 mg/kg per week. In each year of treatment, about 80% of the subjects maintained an increase in growth rate greater than the defined limit (greater than 1 cm/yr above pretreatment growth rate) for continuation of human growth hormone treatment. Comparison of the group that continued to respond to human growth hormone with the group that did not maintain an accelerated growth rate did not reveal differences in bone age delay, sleep or secretagogue-stimulated human growth hormone secretion, degree of short stature either absolute or relative to target height, and somatomedin C concentration before or after initiation of therapy. The group that failed to respond to the human growth hormone treatment in the first year of treatment was younger and had a higher pretreatment growth rate. Review of the longitudinal growth curves revealed five patterns of response to human growth hormone treatment: (1) failure to increase growth rate in two subjects with height SD scores within 1 SD of target height, (2) failure to increase growth rate in five subjects with height SD scores greater than 1 SD less than the target height, (3) acceleration in growth rate in three subjects that was not maintained until achievement of a height within 1 SD of the target height, (4) acceleration of growth rate in five subjects that was maintained until achievement of a height within 1 SD of the target height, and (5) acceleration in growth rate that was maintained during the 3 years of treatment in 15 subjects who had not attained a height within 1 SD of the target height. We conclude that human growth hormone treatment of some but not all short children with "normal" growth hormone secretion will result in sustained acceleration of growth rate and attainment of prepubertal heights that are closer to but do not exceed their genetic height potential. A clinical trial of human growth hormone may be necessary to determine which subjects will benefit from the treatment.     

人生长激素同型异构体比例变化与特发性矮小症的相关性

人生长激素(human growth hormone,hGH)是出生后促进生长的主要激素,生长激素在调节生长的许多方面都起作用,生长激素缺乏会引起生长激素缺乏性矮小(growth hormone deficiency,GHD),但特发性矮小症患儿(idiopathic short stature,ISS)并不存在生长激素(GH)缺乏[1],其发病机制一直是研究的热点,有研究认为hGH同型异构体(humangrowth hormone isoforms,hGHI)比例的变化可能是ISS的发病机制之一[2,3],hGH有多种同型异构体,在垂体、胎盘和外周血中均存在,各种hGHI单体型的22kDa!hGHI含量最丰富,20kDa!hGHI含量次之,它们在结构上有…