Natural history of growth hormone deficiency in a pediatric cohort

Childhood growth hormone treatment: challenges, opportunities, and considerations

With long standing demand and popularity, growth hormone treatments continue to be a topic of interest for paediatric endocrinologists and general paediatricians due to ongoing issues regarding their long-term effects, the safety of childhood treatment, and the introduction of long-acting growth hormone preparations in the past decade. Moreover, uncertainty regarding how to approach individual patients and their treatment indications remains, particularly concerning tailored treatment goals and objectives; this uncertainty is further complicated by the multitude of approved indications that surpass substitution therapy. The paediatric endocrinologist thus grapples with pertinent questions, such as what defines reasonable treatment goals for each individual given their indications, and when (and how) to initiate the necessary discussions about risks and benefits with patients and their families. The aim of this Review is to offer advanced physiological concepts of growth hormone function, map out approved paediatric indications for treatment along with evidence on their effects and safety, highlight controversies and complexities surrounding childhood growth hormone treatment, and discuss the potential of long-acting growth hormone and future directions in the realm of childhood growth hormone treatment.

Optimal final adult height achieved by low-dose recombinant human growth hormone therapy

Background

Thailand has been administering the recombinant human growth hormone (rhGH) treatment for >20 years. Due to limited resources being available, efforts have been directed toward utilizing rhGH at the lowest feasible dose. However, there is currently a lack of evidence in terms of the efficacy and outcomes.

Objective

To evaluate the auxological outcomes of growth hormone (GH) treatment and the GH secretion ability after reaching final adult height (FAH) and discontinuing rhGH.

Methods

Data of 40 patients were retrospectively reviewed. The clinical characteristics, auxological data, and results of biochemical and endocrine investigations before and during rhGH treatment were evaluated. In addition, GH retesting was performed in 24 patients using the insulin tolerance test.

Results

Twenty patients (50%) had complete growth hormone deficiency (GHD), defined as peak stimulated GH level <5 ng/mL, and the remaining patients had partial GHD. Most patients were male (n = 25, 62.5%). The mean age at which rhGH was initiated was 8.9 years. Patients with partial GHD received a higher dose of rhGH than those with complete GHD (30.9 µg/kg/d vs. 26.2 µg/kg/d, P = 0.02). Patients with complete and partial GHD reached FAH at height standard deviation scores (SDSs) of -0.65 and -1.47, respectively. The factors associated with obtaining a good clinical response in terms of height gain included peak-stimulated GH level, age of puberty, and age of discontinuing rhGH. After completing the rhGH treatment, 13 of the 24 patients showed normal GH secretion. Patients with multiple pituitary hormone deficiency (MPHD) were likely to have persistent GHD through adulthood (n = 8, 88.9%).

Conclusion

This study has demonstrated that the use of low-dose rhGH could result in healthy populations achieving optimal FAHs. Patients with MPHD might not require retesting as they were likely to have persistent GHD. The results obtained in this research highlight the benefits of the treatment. This treatment can be applied in resource-limited countries.

The landscape of retesting in childhood-onset idiopathic growth hormone deficiency and its reversibility: a systematic review and meta-analysis

OBJECTIVE

Children diagnosed with idiopathic isolated growth hormone deficiency (IGHD) are frequently observed to no longer be GH-deficient at a later stage of growth as a result of 'GHD reversal'. Reevaluation of GH status by stimulation test is currently incorporated into management guidelines at attainment of final height (FH). Over the past three decades, numerous studies have evaluated reversal rates using different methodologies including crucial parameters like GHD aetiology, GH cut-off and retesting time point, with heterogeneous results. We aimed to systematically analyse the reversibility of childhood-onset IGHD dependent on retesting GH cut-offs and retesting time points.

METHODS

PubMed, Cochrane Library, TRIP database and NHS Evidence were searched for publications investigating the reversibility of IGHD from database initiation to 30 June 2020 following PRISMA recommendations. Study cohorts were pooled according to retesting GH cut-off and time point. Reversal rates were calculated using random-effects models.

RESULTS

Of the 29 studies initially identified, 25 provided sufficient detail for IGHD analysis, resulting in 2030 IGHD patient data. Reversal rates decreased significantly as the retesting GH cut-off increased (P = 0.0013). Pooled (95% CI) reversal rates were 80% (59-92%, n = 227), 73% (62-81%, n = 516) and 55% (41-68%, n = 1287) for cohorts using retesting GH cut-offs of 3-4 ng/mL, 5-6 ng/mL and 7.7-10 ng/mL, respectively. Individuals retested at FH (n = 674) showed a pooled reversal rate of 74% (64-82%) compared to 48% (25-71%) when retested before FH (n = 653).

CONCLUSION

Provided evidence supports reevaluation of current IGHD management guidelines. The high reversal rates should instigate consideration of early retesting.

Economic burden of growth hormone deficiency in a US pediatric population

BACKGROUND: Pediatric growth hormone deficiency (GHD) is a rare disorder of short stature that is currently treated with daily injections of somatropin. In addition to short stature, GHD is associated with other comorbidities such as impaired musculoskeletal development, cardiovascular disease, and decreased quality of life. OBJECTIVE: To analyze somatropin utilization, adherence, and health care costs among children with GHD who had either Medicaid or commercial health insurance. METHODS: Children (aged < 18 years) with a GHD diagnosis between January 1, 2008, and December 31, 2017, were identified in the IBM MarketScan Commercial and Medicaid databases. Patients with at least 12- and 6-month continuous enrollment pre- and postdiagnosis were eligible. Children with GHD were direct matched (1:3) to controls without GHD (or other short stature-related disorders) on age, gender, plan type, region, and race (Medicaid only). Index date was the date of the first GHD diagnosis during the selection window for GHD patients and using random assignment for controls. Patients were followed until the end of continuous database enrollment or December 31, 2018. Baseline comorbidities and medications were measured during the 12 months pre-index, whereas somatropin treatment patterns along with all-cause and GHD-related health care costs were measured during the variable follow-up period. Multivariable modeling was used to compare costs between GHD patients and controls and between somatropin-treated and -untreated GHD patients while adjusting for baseline characteristics. RESULTS: There were 6,820 Medicaid and 14,070 commercial patients with GHD who met the study inclusion criteria. Mean (SD) age at index was 9.5 (4.5) years for Medicaid patients and 11.1 (3.7) years for commercial patients. The majority of patients were male (> 65%), and mean follow-up time for all cases and controls was 3-4 years. Overall, 63.2% of Medicaid and 68.4% of commercial GHD patients were treated with somatropin at some point during follow-up. Among Medicaid GHD patients, the treatment rate was highest among White males and lowest among Black females. Adherence was low as the proportion of days covered was ≥ 80% for only 18.4% of Medicaid patients and 32.3% of commercial patients and 49.1% of treated Medicaid and 24.3% of treated commercial patients discontinued before turning age 13. After adjusting for baseline characteristics, all-cause non-somatropin annualized costs were 5.67 times higher (Δ$19,309) for Medicaid GHD patients and 5.46 times higher (Δ$12,305) for commercial GHD patients than matched non-GHD controls. Adjusted all-cause non-somatropin annualized costs were 0.59 times lower (Δ$14,416) for treated Medicaid patients and 0.69 times lower (Δ$7,650) for treated commercial patients than for untreated patients. CONCLUSIONS: Pediatric GHD presents a significant health care burden, and many patients remain untreated or undertreated. Untreated GHD was associated with higher non-somatropin health care costs than treated GHD. Strategies to optimize treatment and improve adherence may reduce the health care burden faced by these patients. DISCLOSURES: This study was funded by Ascendis Pharma, Inc. Smith and Pitukcheewanont are employed by Ascendis Pharma, Inc. Manjelievskaia, Lopez-Gonzalez, and Morrow are employed by IBM Watson Health, which received funding from Ascendis Pharma, Inc., to conduct this study. Kaplowitz is a paid consultant of Ascendis Pharma, Inc.

Low muscle mass and strength in pediatrics patients: Why should we care?

Skeletal muscle plays major roles in metabolism and overall health across the lifecycle. Emerging evidence indicates that prenatal (maternal diet during pregnancy and genetic defects) and postnatal factors (physical activity, hormones, dietary protein, and obesity) influence muscle mass acquisition and strength early in life. As a consequence, low muscle mass and strength contributes to several adverse health outcomes during childhood. Specifically, studies demonstrated inverse associations of muscle mass and strength to single and clustered metabolic risk factors. The literature also consistently reports that low muscle mass and strength are associated with reduced bone parameters during growth, increasing the risk of osteoporosis in old age. Furthermore, muscle mass gains are associated with improved neurodevelopment in the first years of life. Given these negative implications of low muscle mass and strength on health, it is crucial to track muscle mass and strength development from childhood to adolescence. Several body composition techniques are currently available for estimation of muscle mass, all with unique advantages and disadvantages. The value of ultrasound as a technique to measure muscle mass is emerging in pediatric research with potential for translating the research findings to clinical settings. For the assessment of muscle strength, the handgrip strength test has been widely employed but without a standardized protocol. Although further research is needed to define normative data and cut points for the low muscle mass and strength phenotype, the use of such non-invasive medical monitoring is a promising strategy to identify early abnormalities and prevent low muscle mass in adulthood.

Auxological characteristics of pediatric patients with permanent or transient isolated growth hormone deficiency. Response to treatment and final height

INTRODUCTION

Treatment with recombinant human growth hormone (rhGH) has been shown to improve adult height in pediatric patients with GH deficiency (GHD). However, reassessment of patients after they reach their final height shows some of them have permanent GH deficiency (PGHD), while others had a transient deficiency (TGHD). The study objective was to assess, in a cohort of pediatric patients with GHD, potential differences in response to treatment with rhGH depending on whether deficiency is permanent or transient.

MATERIALS AND METHODS

A retrospective study of 89 patients with GHD, who were monitored from diagnosis to adult height. Clinical, auxological, radiographic and laboratory variables were collected at diagnosis, after the first year of treatment, and when they had reached their adult height.

RESULTS

PGHD was found in 28% of patients. Initial height was -2.46 ± 0.86 SD and -2.24 ± 0.68 SD in subjects with PGHD and TGHD respectively. Peak GH level at diagnosis was 4.26 ± 2.78 and 6.20 ± 2.01 ng/mL (p < 0.01) in the PGHD and TGHD groups respectively. After the first year of treatment, increase in growth velocity was greater in the PGHD group: 4.33 ± 3.53 SD vs. 2.95 ± 2.54 SD in the PGHD group (p = 0.043). Final height was -0.81 ± 0.87 SD in the PGHD and -0.95 ± 0.83 SD in the TGHD group (p = 0.47).

CONCLUSIONS

Patients with PGHD had a better short- and long-term response to rhGH. They also showed lower GH levels in stimulation tests at diagnosis, as previously reported.