Short stature and growth hormone use in pediatric hemodialysis patients

End-stage renal disease (ESRD) causes growth retardation in children, and poor growth has been linked to worse outcomes. Recombinant human growth hormone (rhGH) can increase growth velocity and final adult height in pediatric ESRD patients. We aimed to identify clinical predictors of short stature (height standard deviation score (Ht SDS) <-1.88) and rhGH use in short stature pediatric hemodialysis patients. In 2002, the Centers for Medicare & Medicaid Services (CMS) Clinical Performances Measures (CPM) ESRD Project collected demographic, clinical and laboratory data as well as rhGH use on all in-center hemodialysis patients in the US aged <18 years. The odds ratios (OR) of short stature and rhGH use for individual predictors were determined by multivariate logistic regression modeling. Six-hundred and fifty-one (92%) of 710 eligible patients were included for analysis. Of these, 266 (41%) had Ht SDS <-1.88. After adjustment, short stature was predicted by congenital/urologic causes of ESRD ((OR 5.4; 95% confidence interval [CI], 2.1-13.8; p <0.001) in patients aged 10-14 years; (OR 2.8; 95% CI, 1.5-5.4; p <0.01) in patients aged 15-18 years) and increasing years on dialysis ((OR 1.2; 95% CI, 1.1-1.4; p <0.01) in patients aged 10-14 years; (OR 1.2; 95% CI, 1.1-1.4; p <0.001) in patients aged 15-18 years). Of 266 short stature patients, 214 (80.5%) had data on rhGH use. Of these, 80 (37%) had been prescribed rhGH. After adjustment, use of rhGH in short-stature patients was predicted by white race (OR 2.1; 95% CI, 1.1-4.0; p <0.05), increasing years on dialysis (OR 1.13; 95% CI, 1.05-1.22; p <0.01) and patients with BMI <16.6 kg/m(2) (OR 3.1; 95% CI, 1.2-8.4; p <0.05). Increasing age and level of intact parathyroid hormone were not associated with rhGH use among short stature patients. A significant proportion of pediatric hemodialysis patients have short stature. The majority of short-stature patients are not receiving rhGH. Patients with short stature who are white, have longer durations on dialysis and have lower BMI are more likely to receive rhGH.

GH treatment reduces trunkal adiposity in HIV-infected patients with lipodystrophy: a randomized placebo-controlled study

OBJECTIVE

HIV lipodystrophy is a common complication of highly active anti-retroviral therapy, characterized by both metabolic and morphological features. The most feared morphological feature is body fat redistribution leading to HIV lipodystrophy. GH is known to induce reduction of visceral obesity and body fat redistribution in adults.

DESIGN

A crossover, double-blind protocol of GH treatment (6 months of recombinant human GH (rhGH) at 0.2 IU/kg per week) vs placebo (6 months of placebo with a 2 month wash-out between periods) was performed.

SUBJECTS AND SETTING

Thirty HIV-infected patients with lipodystrophy were recruited in the Outpatient Clinic of the Division of Infectious Diseases of San Raffaele Scientific Institute in Milan, Italy.

MAIN OUTCOME AND RESULTS

Our data demonstrate an effect of low-dose rhGH administration in reducing trunk adiposity in HIV patients with lipodystrophy (Delta from basal: -394 +/- 814 g, P = 0.048 with respect to placebo. Data are given as mean +/- standard deviation). A trend to an increase of arm depots was also shown (Delta from basal: +43 +/- 384 g, P = NS with respect to placebo). Interestingly, no detrimental metabolic effects on glucose tolerance and lipid levels were found following the administration of 0.2 IU/kg per week of rhGH for 6 months.

CONCLUSIONS

Low-dose GH administration is an effective treatment in reducing trunk obesity in HIV-infected patients with lipodystrophy.

New issues in the diagnosis and management of Turner syndrome

This review has tried to update our view of TS, highlighting the less severe phenotype we are seeing today, aiming to motivate clinicians to scrutinize normal looking short girls more closely, and to provide more relevant information for those counseling prospective parents on the implications of a TS karyotype during prenatal screening. New approaches to cardiac evaluation, including imaging with MR and ECG analysis-were suggested to strengthen our ability to detect and prevent potentially life-threatening cardiac complications. The new emphasis on reproductive potential and concerns about the adequacy and safety of current HRT regimens certainly require further studies and adjustment of treatment strategies in light of new priorities and safety concerns. In the same vein, prospective studies are required to assess the outcome and safety of assisted pregnancy in TS, which, despite the warning ofa potential catastrophic increase in maternal morbidity is going to become a much more common occurrence in the near future.

Changes of thyroid function during long-term hGH therapy in GHD children. A possible relationship with catch-up growth?

BACKGROUND

Growth hormone (GH) treatment in patients with GH deficiency (GHD) can determine changes in the thyroid function. The clinical significance of these changes remains controversial, and all studies have so far covered rather a short period--usually no longer than one year.

OBJECTIVE

To determine the effect of long-term recombinant hGH treatment in children with idiopathic GHD on the thyroid function.

PATIENTS AND METHODS

Nineteen prepubertal children (12 boys and 7 girls, mean age 9.2 +/- 3.1 years) with idiopathic GHD were studied and followed for twenty-four months. None of the patients showed multiple pituitary hormone deficiencies. Nineteen healthy children matched for age and sex acted as controls.

RESULTS

Patients with GHD showed a significant increase in TT (3) at twelve months and in FT (3) at six and twelve months after starting GH treatment, with a significant decrease at eighteen and twenty-four months. TT (4) level decreased significantly at twelve months and increased significantly at eighteen and twenty-four months. FT (4) also decreased, but only slightly, after twelve months of hGH treatment, and then increased significantly at twenty-four months. TSH levels did not vary significantly during the course of therapy. TT (3)/TT (4) and FT (3)/FT (4) ratios increased significantly after six and twelve months of therapy and significantly decreased later, approaching pre-therapy values. The SDS of Growth Velocity (SDS-GV) increased remarkably during the first year of therapy and then decreased significantly during the second year, although it remained significantly higher than the pre-therapy values. TT (3) and TT (3)/TT (4) ratio displayed a significant correlation with SDS-GV at twelve months of therapy. In a multiple regression analysis with age, bone age, parental height, GH dose, TT (3,) TT (3)/TT (4), and the SDS of IGF-I, only the TT (3)/TT (4) ratio at twelve months of therapy (p < 0.001) was identified as a significant predictor of SDS-GV.

CONCLUSION

Our data confirm that changes in thyroid function are present in GHD children during long-term hGH therapy. These changes probably resulted from the effect of hGH on the peripheral metabolism of thyroid hormones and appear to be transitory, disappearing during the second year of hGH treatment. We speculate on the functional significance of these changes, and in particular, on their role in catch-up growth after hGH therapy.

Variability of isolated autosomal dominant GH deficiency (IGHD II): impact of the P89L GH mutation on clinical follow-up and GH secretion

OBJECTIVE

Four distinct familial types of isolated GH deficiency (IGHD) are classified, of which type II, IGHD II, is the autosomal dominant inherited form. Based on clinical data, it became evident that there is a wide variability in phenotype among the various GH-1 gene alterations leading to the disorder. As subjects suffering from IGHD II caused by the specific missense mutated P89L GH (C6129T) have never been reported in detail, the aim was to analyse the impact of this mutated GH form on its clinical follow-up as well as to study its effect at the cellular level in comparison with the most common missense mutation R183H GH (G6664A).

METHODS

Twelve subjects belonging to four families presenting with P89L GH were clinically compared with 17 subjects from 5 families with the R183H GH missense mutation. Further, co-localization of the wild-type (wt-type) and mutant GH forms was studied in AtT-20 cells, mouse pituitary gland, applying quantitative confocal microscopy analysis. Using immunofluorescent techniques, cells were double stained for GH and one of the following organelles: endoplasmic reticulum (anti-Grp94), Golgi (anti-betaCOP) and secretory granules (anti-Rab3a). In addition, GH secretion and cell viability was analysed in detail.

RESULTS

Importantly, as well as growth hormone deficiency, eight out of twelve subjects with the P89L mutated GH form developed other endocrine deficits and the pituitary gland became smaller over time (P < 0.05). At the cellular level, quantitative analysis of the variable mutants expressed in AtT-20 cells revealed a different extent of co-localization, different effects on GH secretion, and, therefore, a different impact on the secretory pathway which might be caused by different folding or aggregation problems necessary for sorting, packaging and/or secretion through the regulated secretory pathway.

CONCLUSIONS

Our results show that specific and detailed analyses of the different mutations identified in IGHD II may shed light on the different mechanisms of secretory pathophysiology, and may provide a better explanation of the range of clinical features associated with GH missense isoforms. Importantly, the findings in patients with P89L GH extend beyond classical IGHD and stress the need for continued clinical vigilance in IGHD II patients for the development of other hormonal deficiencies.

Quality of Life in Adolescents Born Small for Gestational Age: Does Growth Hormone Make a Difference?

BACKGROUND/AIMS

To evaluate quality of life (QoL) in adolescents born SGA without spontaneous catch-up growth, treated with and without long-term growth hormone (GH) therapy. Additionally, to assess whether GH treatment has a positive effect on QoL, besides improving adult height and height SDS during childhood.

METHODS

Two groups of adolescents born SGA without spontaneous catch-up growth participated in the QoL evaluation; a GH-treated group (n = 44, mean GH duration: 8.8 (1.7) years) and an untreated group (n = 28), both mean age 15.8 (2.1) years. QoL was measured by self-reports of the TACQOL-S, a disorder-specific questionnaire, and the CHQ, a generic questionnaire.

RESULTS

The GH group scored significantly better health status and health-related QoL on several scales of the TACQOL-S. On all TACQOL-S scales the GH group scored better QoL than the untreated group, with effect sizes of moderate to large, not all differences reaching statistical significance. The generic CHQ did not reveal significant differences in QoL between the GH group and the untreated group.

CONCLUSIONS

Firstly, adolescents born SGA, with a GH-induced improved height, had in many aspects a better QoL than untreated adolescents born SGA, according to the disorder-specific questionnaire. Secondly, we advise to use, in addition to a generic questionnaire, a disorder-specific questionnaire for measuring QoL in children treated for short stature, as the generic CHQ did not reveal such differences.

Difficulties in Patient Management Associated with the Transition Period

The European Society for Paediatric Endocrinology (ESPE) held a consensus workshop in Manchester, UK, in December 2003 to discuss issues relating to the care of growth hormone (GH)-treated patients in the transition from paediatric to adult life. Aspects under consideration included the definition of transition, the process of delivery of transitional care, the exact need to reassess pituitary status after completion of growth and puberty in teenagers who have received GH treatment during childhood, the most appropriate biochemical definition of severe GH deficiency (GHD) in the transitional period, and the factors influencing both the decision to reinstitute treatment and also the timing and dosage schedule when GH treatment is reinstituted.

Drug bust

The nightly news might not show handcuffed doctors marching off to jail any time soon. But the widespread use of growth hormone to fight aging breaks the law, warns a group of researchers--plus it relies on shaky science.

Alterations in the oxidant-antioxidant status in prepubertal children with growth hormone deficiency: effect of growth hormone replacement therapy

OBJECTIVE

Growth hormone deficiency (GHD) in adults is associated with increased oxidative stress determined by the underlying GH-IGF-1 axis alterations. Despite GHD being a common diagnosis in children with short stature, no data on the oxidant/antioxidant status are available in this age group. This study was designed to detect differences in oxidative stress parameters between prepubertal GH-deficient children and healthy controls. Furthermore, the effect of 12 months of conventional GH replacement (rGH) on oxidant-antioxidant status was evaluated in the GHD group only.

PATIENTS

Ten (nine males and one female) prepubertal children (mean age 9.1 +/- 1.3 years) with GHD were recruited and matched for sex and age (9.2 +/- 1.9 years) with 20 healthy controls (18 males and two females).

MEASUREMENTS

At study entry, lag phase, an index of susceptibility of low density lipoprotein (LDL) to in vitro oxidation, malondialdehyde (MDA) and vitamin E were measured in all subjects. These parameters were also evaluated in GH-deficient children after 12 months of rGH treatment.

RESULTS

The lag phase was significantly decreased in GH-deficient children compared to healthy controls (15.50 +/- 7.4 vs. 43.00 +/- 9.2 min; P = 0.0007), while MDA was significantly increased (1.33 +/- 0.38 vs. 0.46 +/- 0.10 nmol/mg; P = 0.0006). Vitamin E levels were significantly decreased (22.44 +/- 9.57 vs. 35.38 +/- 16.49 micromol/l; P = 0.001). IGF-1 and IGFBP-3 correlated directly to lag phase (r = 0.48; P = 0.01; r = 0.63, P = 0.002, respectively) and to vitamin E (r = 0.59, P = 0.003; r = 0.58, P = 0.006, respectively). By contrast, IGF-1 and IGFBP-3 correlated indirectly to MDA (r = -0.47, P = 0.01; r =-0.65, P = 0.002, respectively). After 1 year of rGH therapy, lag phase (39.32 +/- 15.24 min; P = 0.005) and vitamin E (34.9 +/- 7.7 micromol/l; P = 0.005) increased significantly, while MDA decreased significantly (0.71 +/- 0.42 nmol/mg; P = 0.005), reaching normal levels.

CONCLUSIONS

These data show that children with GHD have substantially increased oxidative stress parameters compared to healthy controls and demonstrate a normalization of these parameters after 1 year of rGH therapy.

Effect of growth hormone therapy and puberty on bone and body composition in children with idiopathic short stature and growth hormone deficiency

The state of bone health and the effect of growth hormone (GH) therapy on bone and body composition in children with idiopathic short stature (ISS) are largely unknown. A direct role of GH deficiency (GHD) on bone density is controversial. Using dual-energy X-ray absorptiometry, this study measured total body bone mineral content (TB BMC), body composition, and volumetric bone mineral density (vBMD) at the lumbar spine (LS) and femoral neck (FN) in 77 children (aged 3-17 years) with ISS (n = 57) and GHD (n = 20). Fifty-five children (GHD = 13) receiving GH were followed over 24 months including measurement of bone turnover. At diagnosis, size-corrected TB BMC SDS was greater (P <or= 0.002) and LSvBMD SDS lower (P < 0.03) than zero in both prepubertal ISS and GHD subjects, but FNvBMD SDS was reduced only in the GHD group (P < 0.05). The muscle-bone relation, as assessed by the BMC/lean mass (LTM) ratio SDS was not different between groups. During GH therapy, prepubertal GHD children gained more height (1.58 [0.9] SDS) and LTM (0.87 [0.63] SDS) compared to prepubertal ISS children (0.75 [0.27] and 0.17 [0.25] SDS, respectively). Percent body fat decreased in GHD (-5.94% [4.29]) but not in ISS children. Total body BMC accrual was less than predicted in all groups accompanied by an increase in bone turnover. Puberty led to the greatest absolute, but not relative, increments in weight, LTM, BMI, bone mass, and LSvBMD. Our results show that children with ISS and GHD differ in their response to GH therapy in anthropometry, body composition, and bone measures. Despite low vBMD values at diagnosis in both prepubertal groups, size-corrected regional or TB bone data were generally within the normal range and did not increase during GH therapy in GHD or ISS children. Growth hormone had great effects on the growth plate and body composition with subsequent gains in height, LTM, bone turnover, and bone mass accrual, but no benefit for volumetric bone density over 2 years.

Low Bone Mineral Density in Adolescents with β-Thalassemia

The pervasiveness of low bone mass (LBM) in beta-thalassemia (Thal) patients (pts) is escalating as the average life expectancy of these pts increases. Adolescence is a period of substantial bone accrual, which is crucial for future bone strength. Studies of LBM are prevalent among adults with Thal. However, limited information exists about bone accrual and LBM in adolescents with the disease. Thirty-one pts with beta-Thal (26 Thal major [TM], 5 Thal intermedia [TI]), aged 9-20 years (mean: 15.3 years), 14 males and 17 females, underwent measurement of spinal bone mineral density (BMD) by DEXA (Lunar, Prodigy). Height, weight, body mass index, and Tanner stage were assessed at the time of the BMD measurement. A total of 16.1% of the patients had normal bone mass (Z > or = -1), 22.6% had reduced bone mass (Z = -1 to -2), and 61.3% had low bone mass (Z < or = -2). BMD Z correlated with height and weight Z scores. Some 53.9% of subjects had normal gonadal function and 46.1% had induced puberty with gonadal steroids. BMD Z significantly worsened with age (P < .0001). However, there was no difference in the LBM prevalence between subjects with normal versus those with induced puberty: BMD Z was -2 or less in 71.4% of subjects with normal puberty versus 66.7% in those with induced puberty. Our results indicate a high prevalence of LBM among adolescents with Thal regardless of adequate transfusion and chelation regimens. Bone accrual was found to be suboptimal in adolescents with normal or induced puberty. Thus, calcium and vitamin D supplementation with antiresorptive therapies should be evaluated in the adolescent Thal pt with close monitoring of growth and sexual development.

Safety and efficacy of growth hormone replacement therapy in adults

Limitless supplies of recombinant human growth hormone (GH) have been available for the last 20 years. During that period, studies have characterised the effects of GH deficiency in adults and the benefits of GH replacement therapy. Areas of greatest impairment and benefit are quality of life, skeletal health and cardiovascular risk factors including the serum lipid profile and body composition. By optimising GH replacement therapy at various stages of adult life, it is hoped that it will prevent the development of osteoporosis and reduce the mortality and morbidity associated with hypopituitarism. However, the primary indication for GH therapy in adults in England and Wales is quality of life. The benefits of GH treatment are sustained over several years, and long-term surveillance of patients continues.

Differential effect sizes of growth hormone replacement on Quality of Life, well-being and health status in growth hormone deficient patients: a meta-analysis

Background

Patients with growth hormone deficiency (GHD) frequently report to suffer from an impaired Quality of Life (QoL) and growth hormone (GH) substitution is found to improve this. However, the same test may be used for measuring QoL, well-being or health status in different studies. QoL has been defined as the subjective appraisal of one's current life based primarily on psychological function. The most important in the appraisal of well-being is mental function and concerning health status patients evaluate physical function as most important. To differentiate the effects of GH replacement on psychological variables in patients with GHD we carried out a number of meta-analyses, classifying questionnaires into instruments measuring QoL, psychological well-being and health status.

Methods

We searched the electronic databases PUBMED and PiCarta from 1985 to 2004. Studies were included that evaluated the effect of GH on patient-reported outcomes in adults with GHD (aged 18 years and above). According to generally accepted definitions we classified the questionnaires as instruments measuring QoL, well-being and health status. By means of meta-analyses the average effect size (d) for QoL, well-being and health status was calculated.

Results and Discussion

Based on open studies GH replacement is found to improve QoL with a small effect size (d = 0.18), well-being with a medium effect size (d = 0.47) and health status with a small effect size (d = 0.26). As the effect size of well-being is most pronounced the generally reported effects of GH replacement on QoL may be overestimated and actually reflect the effect on well-being.

Conclusion

To get more insight in the specific psychological effects of GH treatment it is recommended that instruments selected for these studies should be more consistently classified as instruments measuring QoL, well-being or health status.

Cardiac and peripheral actions of growth hormone and its releasing peptides: relevance for the treatment of cardiomyopathies

Ischemic and nonischemic cardiomyopathies are associated with significant morbidity and mortality in industrialized countries. Cardiomyopathies of primary origin, and more specifically the dilated form of the disease, have been associated with a number of gene defects in cytoskeletal, membrane, and sarcomeric proteins. Cardiomyopathies of secondary origin such as ischemic cardiomyopathy remain the leading cause of left ventricular systolic dysfunction and heart failure. Among novel strategies to improve cardiac function in heart failure, treatment with growth hormone, insulin growth factor-1 (IGF-1), and natural and synthetic growth hormone-releasing peptides such as ghrelin and hexarelin have been explored. The present review focuses on the issues involved in the use of exogenous growth hormone and its releasing peptides in experimental animal models of chronic heart failure and in clinical studies on cardiomyopathic patients as potential releasing peptides for the treatment of chronic heart failure developing as a consequence of cardiomyopathy.

Treatment of pituitary tumors: pegvisomant

Pegvisomant is a pegylated analog of growth that functions as a growth hormone receptor antagonist. The drug is capable of normalizing serum IGF-I concentrations (the chief mediator of disease activity in acromegaly) in 97% of patients, and therapy is associated with significant improvements in the symptoms and signs of GH excess. Biochemical control may be achieved with pegvisomant in patients wholly or partially resistant to somatostatin analogs, and there are emerging data to suggest that the drug may be particularly suitable for patients with acromegaly and co-existent diabetes mellitus.

Improvement in insulin sensitivity without concomitant changes in body composition and cardiovascular risk markers following fixed administration of a very low growth hormone (GH) dose in adults with severe GH deficiency

OBJECTIVE

Untreated GH-deficient adults are predisposed to insulin resistance and excess cardiovascular mortality. We showed previously that short-term treatment with a very low GH dose (LGH) enhanced insulin sensitivity in young healthy adults. The present study was therefore designed to explore the hypothesis that LGH, in contrast to the standard GH dose titrated to normalize serum IGF-I levels (SGH), may have differing effects on insulin sensitivity, body composition, and cardiovascular risk markers [lipid profile, C-reactive protein (CRP), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and adiponectin] in adults with severe GH deficiency.

PATIENTS AND METHODS

In this 12-month open, prospective study, 25 GH-deficient adults were randomized to receive either a fixed LGH (0.10 mg/day, n = 13) or SGH (mean dose 0.48 mg/day, n = 12), and eight age- and body mass index (BMI)-matched GH-deficient adults acted as untreated controls. Fasting blood samples were collected at baseline and at months 1, 3, 6, 9 and 12. Assessments of insulin sensitivity, using the hyperinsulinaemic euglycaemic clamp technique, and body composition, using dual-energy X-ray absorptiometry, were performed at baseline and at month 12.

RESULTS

The LGH decreased fasting glucose levels (P < 0.01) and enhanced insulin sensitivity (P < 0.02), but body composition, nonesterified fatty acid (NEFA) levels and cardiovascular risk markers were unchanged. The SGH did not modify insulin sensitivity, decreased truncal fat mass (P < 0.05), CRP (P < 0.05) and IL-6 (P < 0.05) levels, and increased NEFA levels (P < 0.05). No changes were observed with the untreated controls.

CONCLUSION

Our data indicate that, in contrast to the SGH, fixed administration of the LGH enhances insulin sensitivity with no apparent effects on body composition, lipolysis and other surrogate cardiovascular risk markers in adults with severe GH deficiency. Thus, the LGH may potentially be a beneficial replacement dose in reducing type 2 diabetes risk in adults with severe GH deficiency.

Growth and growth hormone in children born small for gestational age

Although most children born small for gestational age catch up in growth by age 2 y, up to 14% remain more than 2 standard deviations below the mean for height. Recombinant growth hormone is approved by the US Food and Drug Administration and by the European Agency for Evaluation of Medicinal Products for the treatment of children born small for gestational age who fail to manifest catch-up growth by 2 y or 4 y, respectively.

CONCLUSION

We conclude from clinical studies that growth hormone therapy can induce catch-up growth in these children.