Beneficial effects of one-year growth hormone administration to children with juvenile chronic arthritis on chronic steroid therapy. I. Effects on growth velocity and body composition

Growth and puberty in children with juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis is one of the most prevalent chronic diseases in children, with an annual incidence of 2-20 cases per 100,000 and a prevalence of 16-150 per 100,000. It is associated with several complications that can cause short-term or long-term disability and reduce the quality of life. Among these, growth and pubertal disorders play an important role. Chronic inflammatory conditions are often associated with growth failure ranging from slight decrease in height velocity to severe forms of short stature. The prevalence of short stature in JIA varies from 10.4% in children with polyarticular disease to 41% of patients with the systemic form, while oligoarthritis is mostly associated with localized excessive bone growth of the affected limb, leading to limb dissymmetry. The pathogenesis of growth disorders is multifactorial and includes the role of chronic inflammation, long-term use of corticosteroids, undernutrition, altered body composition, delay of pubertal onset or slow pubertal progression. These factors can exert a systemic effect on the GH/IGF-1 axis and on the GnRH-gonadotropin-gonadic axis, or a local influence on the growth plate homeostasis and function. Although new therapeutic options are available to control inflammation, there are still 10-20% of patients with severe forms of the disease who show continuous growth impairment, ending in a short final stature. Moreover, delayed puberty is associated with a reduction in the peak bone mass with the possibility of concomitant or future bone fragility. Monitoring of puberty and bone health is essential for a complete health assessment of adolescents with JIA. In these patients, an assessment of the pubertal stage every 6 months from the age of 9 years is recommended. Also, linear growth should be always evaluated considering the patient's bone age. The impact of rhGH therapy in children with JIA is still unclear, but it has been shown that if rhGH is added at high dose in a low-inflammatory condition, post steroids and on biologic therapy, it is able to favor a prepubertal growth acceleration, comparable with the catch-up growth response in GH-deficient patients. Here we provide a comprehensive review of the pathogenesis of puberty and growth disorders in children with JIA, which can help the pediatrician to properly and timely assess the presence of growth and pubertal disorders in JIA patients.

Clinical Patterns and Linear Growth in Children with Congenital Adrenal Hyperplasia, an 11-Year Experience

OBJECTIVE

An important goal in treating children with congenital adrenal hyperplasia (CAH) is to achieve a normal final adult height (FH). The aim of this study was to describe the clinical presentations and evaluate linear growth and possible factors affecting it in children with CAH.

METHODS

This is a retrospective study of 56 patients with CAH followed up in a tertiary center for 11 years. Patient's data including demographics, clinical, anthropometric, and laboratory information at presentation and during follow-up period were collected from medical records.

RESULTS

Fifty-six children (31 females) with CAH were seen at KAMC-Jeddah over 11-year period and 91% were 21-hydroxylase deficient. Of these, 46.4% had hyponatremia and 28.6% had hyperkalemia (21.4% had hyponatremia and hyperkalemia) at presentation. Positive family history was documented in 53.6%. Ambiguous genitalia were present in 72% of females and the majority required corrective surgery. Males had significantly decreased HtSDS versus females and females had significantly higher body mass index. The HtSDS of children who had had higher 17OHP or salt-losing crisis during treatment was significantly lower than those who had normal 17OHP and those who did not have salt-losing crisis, respectively.

CONCLUSION

The final height outcome in our patients with CAH treated with glucocorticoids is lower than the population norm. Proper control of the disease clinically and biochemically through strict compliance to medical therapy as well as close clinical and laboratory monitoring is an important key to achieve normal final adult height in these patients. Side effects, including overweight, obesity, and hypertension are true risk associations and need timely diagnosis and early management.

Effects of exogenous growth hormone administration on dexamethasone-induced growth impairment in adolescent male rats

Growth impairment (GI) is one of the adverse effects of dexamethasone (DXM), and growth hormone (GH) has been used clinically to improve GI. The present study aimed to evaluate the manner in which DXM disturbs the growth rate of longitudinal bones, and the recovery effects of GH on DXM-induced GI in the longitudinal bones of adolescent male rats. In the first experiment, DXM (0, 0.5, 1, 2 and 5 mg/kg) was administered subcutaneously to identify a potential dose-dependent activity and calculate the median effective dose (ED50) of DXM-induced GI. The ED50 was identified to be 1.15 mg/kg. In the second experiment, GH (0, 2.5, 5 and 10 mg/kg) with 1.15 mg/kg DXM was injected subcutaneously to assess the recovery effects of GH on DXM-induced GI. The growth rates of the longitudinal bones, total height of the growth plate, local mRNA expressions of insulin-like growth factor 1 (IGF-1), GH receptor (GHR) and IGF-1 receptor (IGF-1R), and local protein expression of IGF-1 were measured to evaluate the recovery effects of GH on DXM-induced GI. The local expressions of IGF-1, GHR and IGF-1R mRNA, and IGF-1 protein were measured using quantitative polymerase chain reaction following laser microdissection and antigen-specific immunohistochemistry, respectively. GH administration partially recovered DXM-induced GI in the longitudinal bones and growth plate. GH significantly increased the levels of IGF-1, GHR and IGF-1R mRNA in the proliferative zone of the control group (P<0.05), whereas it failed to increase them in the proliferative zone of the DXM-treated group. Furthermore, GH increased the levels of IGF-1, GHR and IGF-1R mRNA in the hypertrophic zone of both the vehicle and DXM-treated groups (P<0.05). Immunohistochemical analysis of IGF-1 protein expression revealed a similar pattern to that of IGF-1 mRNA. These results suggest that increased GH insensitivity in the proliferative zone of the growth plate, induced by DXM, leads to GI in longitudinal bones. Thus, combined administration of GH with GH insensitivity-alleviating medications may be more effective in the treatment of DXM-induced GI.

Growth abnormalities in children and adolescents with juvenile idiopathic arthritis

In patients with juvenile idiopathic arthritis (JIA) growth impairment and variance in body composition are well-known long-term complications. In the active phases of the disease, particular patients with systemic and polyarticular JIA reveal growth impairment. Some experience "catch-up" growth following reduction in disease activity and lower glucocorticoid doses. Although new therapeutic options are available, there are still 10-20 % of patients with severe forms of the disease who show continuous growth disturbance. Only few studies have specifically addressed body composition in JIA. Bone mass deficits in part could be related to the deficits of muscle mass. Study data on growth hormone treatment in short children with JIA are promising in respect of growth development, final height and body composition. The major goal for physicians is optimal disease control while maintaining normal growth and body composition. Early recognition of patients who develop prolonged growth and body composition disturbances is important as these abnormalities contribute to long-term morbidity and need to be addressed both diagnostically and therapeutically.

Glucocorticoids and the regulation of growth hormone secretion

Glucocorticoids modulate the secretion of growth hormone (GH) by various and competing effects on the hypothalamus and pituitary gland. The final effects of this modulation depend on hormone concentrations and the duration of exposure. The traditional hypothesis is that chronically raised levels of glucocorticoids suppress the secretion of GH. However, a functional impairment of the GH reserve might also be observed in patients with low levels of glucocorticoids, such as those with secondary hypoadrenalism, which is consistent with the model of biphasic dose-dependent effects of glucocorticoids on the somatotropic axis. This Review updates our current understanding of the mechanisms underlying the effects of glucocorticoids on the secretion of GH and the clinical implications of the dual action of glucocorticoids on the GH reserve in humans. This Review will also address the potential diagnostic and therapeutic implications of GH for patients with a deficiency or excess of glucocorticoids.

Final adult height in children with congenital adrenal hyperplasia treated with growth hormone

CONTEXT

Patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency typically reach a final adult height well below their mid-parental target height.

OBJECTIVE

The objective of this study was to examine whether GH alone or in combination with an LHRH analog (LHRHa) improved the final adult height in patients with CAH.

DESIGN

The study was a nonrandomized prospective study.

SETTING

The study was conducted at two university hospitals in New York City, NY.

PARTICIPANTS

Thirty-four patients with CAH treated with GH participated in this study. Nineteen males and 15 females who were predicted to be more than 2 SD below their mid-parental target height or more than 2 SD below the population mean received GH until reaching final adult height. In addition to GH, 27 patients (16 males, 11 females) were also treated with an LHRHa.

INTERVENTION

The mean duration of GH treatment was 5.6 ± 1.8 yr in males and 4.5 ± 1.6 yr in females. The mean duration of LHRHa therapy was 3.7 ± 1.7 yr for both sexes.

MAIN OUTCOME MEASURES

The primary endpoint variables were final adult height, final height discrepancy, and gain in height.

RESULTS

Males reached a significantly higher final adult height (172.0 ± 4.8 cm) than their initial predicted height (162.8 ± 7.7 cm) (P < 0.00001). Females also reached a significantly higher final adult height (162.2 ± 5.3 cm) than initially predicted (151.7 ± 5.2 cm) (P < 0.0000001). Mean gain in height was 9.2 ± 6.7 cm in males and 10.5 ± 3.7 cm in females.

CONCLUSION

Our results indicate that GH alone or in combination with LHRHa improves final adult height in patients with CAH.

Growth hormone treatment in children with rheumatic disease, corticosteroid induced growth retardation, and osteopenia

BACKGROUND

In children with severe rheumatic disease (RD), treatment with corticosteroids (CS) is frequently needed and growth retardation and osteopenia may develop. A beneficial effect of human growth hormone (hGH) has been reported but mostly in trials without a control group.

AIMS

To study the effect of hGH on growth, bone mineral density (BMD), and body composition, taking the disease activity and CS use into account.

METHODS

Randomised controlled trial on 17 prepubertal RD patients with growth retardation and/or decreased BMD. The hGH group (n = 10) received treatment with hGH 4 IU/m2/day (approximately 0.045 mg/kg/day) during two years. The controls (n = 7) received no GH treatment.

RESULTS

During the two year study period the disease activity, and use of CS and methotrexate (MTX) did not differ between the groups. There was a significant mean increase in height standard deviation score (HSDS) in the hGH group (0.42+/-0.16 SDS) and a non-significant decrease in the controls (-0.18+/-0.11 SDS). Change in BMD did not differ significantly between the groups, although the increase in BMD for lumbar spine within the hGH group was significant. Lean body mass improved significantly in the hGH group compared to controls (0.64+/-0.19 SDS versus -0.20+/-0.17 SDS), while the decrease in percentage fat was not significant.

CONCLUSIONS

There was a significant effect of hGH on growth and lean body mass, but a longer duration of treatment might be necessary to evaluate the effect of hGH on BMD.

The pathophysiology of the growth plate in juvenile idiopathic arthritis

Children with chronic inflammatory diseases, such as juvenile idiopathic arthritis (JIA), suffer from a variety of growth disorders. These range from general growth retardation to local acceleration of growth in the affected limb. These disorders are associated with the increased production of proinflammatory cytokines, which may influence growth through a local effect in the growth plates of long bones and/or systemic effects throughout the whole body. In this article we review these aspects and also discuss the evidence for interaction between the inflammatory cytokine and growth-signalling pathways.

Juvenile rheumatoid arthritis: therapeutic perspectives

Juvenile rheumatoid arthritis (JRA) is the most common childhood chronic systemic autoimmune inflammatory disease. The therapeutic approach to JRA has, to date, been casual and based on extensions of clinical experiences gained in the management of adult rheumatoid arthritis (RA). The physiology of inflammation has been systemically studied and this has led to the identification of specific therapeutic targets and the development of novel approaches to the management of JRA. The classical treatments of the disease such as methotrexate, sodium aurothiomalate and sulfasalazine, are not always effective in controlling RA and JRA. This has necessitated the development of novel agents for treating RA, most of which are biological in nature and are targeted at specific sites of the inflammatory cascades. These biological therapeutic strategies in RA have proved successful and are being applied in the management of JRA. These developments have been facilitated by the advances in molecular biology which have heralded the advent of biodrugs (recombinant proteins) and gene therapy, in which specific genes can be introduced locally to enhance in vivo gene expression or suppress gene(s) of interest with a view to down-regulating inflammation. Some of these biodrugs, such as anti-tumor necrosis factor alpha (anti-TNFalpha), monoclonal antibodies (infliximab, adalimumab), TNF soluble receptor constructs (etanercept) and interleukin-1 receptor antagonist (IL-1Ra) have been tested and shown to be effective in RA. Etanercept has now been licensed for JRA. Clinical trials of infliximab in JRA are planned. Studies show that the clinical effects are transient, necessitating repeated treatments and the risk of vaccination effects. Anti-inflammatory cytokines such as IL-4, IL-10, transforming growth factor-beta and interferon-beta (IFN-beta) are undergoing clinical trials. Many of these agents have to be administered parenterally and production costs are very high; thus, there is a need, especially for pediatric use, to develop agents that can be taken orally. Long-term studies will be required to assess the tolerability and toxicity of these approaches in JRA, since cytokines and other mediators play important roles in host defenses, and the chronic inhibition, exogenous administration or constitutive over-expression of some cytokines/mediators may have undesirable effects.