Cardiovascular Disease in Former Pediatric Recipients of Growth Hormone: Another Look at Growth Hormone Safety

The Rising Popularity of Growth Hormone Therapy and Ensuing Orthopedic Complications in the Pediatric Population: A Review

The utilization of recombinant human growth hormone therapy in pediatric populations, originally approved to treat diseases of growth hormone deficiency, has expanded to encompass a broader range of indications, leading to a threefold increase in its utilization in the last two decades. However, concerns regarding its safety, particularly those that are orthopedic in nature, have grown alongside its increasing popularity. Growth hormone usage has been reported to predispose patients to a multitude of common orthopedic conditions, including carpal tunnel syndrome, Legg-Calve-Perthes disease, little league shoulder, Osgood-Schlatter disease, osteochondritis dissecans, scoliosis, Sever's disease, and slipped femoral capital epiphysis. The pathways by which growth hormone therapy can precipitate orthopedic pathology has been shown to be multifactorial, involving mechanisms such as hormonal changes, growth plate instability, rapid growth, and increased susceptibility to overuse injury. This review examines the orthopedic consequences of growth hormone therapy in pediatric patients by discussing these potential pathophysiologic mechanisms of injury and analyzing subsequent clinical manifestations. By examining processes underlying these complications, we highlight the need for orthopedic surveillance and management in children receiving GHT, particularly those with pre-existing musculoskeletal comorbidities or high levels of physical activity. Our findings underscore the importance of a multidisciplinary approach involving co-management by pediatricians, endocrinologists, and orthopedic surgeons to optimize safety and outcomes for these patients. Directions for future research include correlating pathophysiologic mechanisms to injury patterns, investigating long-term complications in recently approved growth hormone therapy indications, and informing clinical guidelines on the management of orthopedic injuries in this patient population.

Growth Hormone Treatment for Non-GHD Disorders: Excitement Tempered by Biology

The success of growth hormone (GH) replacement in children with classical GH deficiency has led to excitement that other causes of short stature may benefit similarly. However, clinical experience has shown less consistent and generally less dramatic effects on adult height, perhaps not surprising in light of increased understanding of GH and growth plate biology. Nonetheless, clinical demand for GH treatment continues to grow. Upon the 20th anniversary of the US Food and Drug Administration's approval of GH treatment for idiopathic short stature, this review will consider the factors underlying the expansion of GH treatment, the biological mechanisms of GH action, the non-GH-deficient uses of GH as a height-promoting agent, biological constraints to GH action, and future directions.

Perceptions of Youth and Parent Decision-Making Roles Regarding Recombinant Human Growth Hormone Treatment

Recombinant human growth hormone (rhGH) is prescribed to youth with growth hormone deficiency (GHD) to support normal growth and ensure healthy physical development, and to youth without GHD to address height concerns. Perceptions of youth involvement in rhGH treatment decisions have not been explored. This study aimed to examine perceptions of youth and parent roles in decisions around rhGH treatment. Youth (n = 22, 11.5 ± 2.0 years) who had undergone evaluation for short stature and their parents (n = 22) participated in semi-structured interviews after stimulation test results had been received. Interviews revealed the following themes: 1) parent provided youth with support; 2) parent facilitated youth's decision-making involvement; 3) youth had no role or did not remember their role; and 4) youth did not remember conversations with their parents or providers. Parents facilitated their children's involvement by sharing information and seeking their opinions. Whereas some participants described youth as having a substantial decision-making role, not all youth felt they were involved, and some youth could not recall conversations about rhGH. Parents can bolster youth involvement by having conversations using developmentally appropriate language, which is critical to youth feeling empowered and developing efficacy over their own care.

Increase of serum lipoprotein (a), an adverse effect of growth hormone treatment

A number of reports show that high endogenous, or therapeutic administration of human growth hormone (hGH) cause an increase of serum lipoprotein a, Lp(a). Being thrombogenic Lp(a) is an independent risk factor of atherosclerotic cardiovascular disease (ASCVD). Hence, it is hypothesized that the recently reported association between childhood hGH treatment and cardiovascular morbidity is probably due to the GH effect on Lp(a) synthesis. It is therefore suggested to determine serum Lp(a) levels before and during hGH treatment in children and adults.

Clinical Indications for Growth Hormone Therapy

Growth hormone (GH) is an injectable medication originally used to replace the deficiency of the hormone, but has expanded to treating conditions that may reduce growth and adult height even when the body maintains endogenous GH production. In the United States, there are 8 Food and Drug Administration (FDA)-approved indications for pediatric GH therapy: GH deficiency, Prader-Willi Syndrome, small for gestational age (SGA) without catch-up growth, idiopathic short stature, Turner syndrome, SHOX gene haploinsufficiency, Noonan Syndrome, and chronic renal insufficiency. We characterize the growth patterns and effects of GH treatment in each of these indications. We also review patterns of growth that warrant referral to a pediatric endocrinologist, as well as safety updates. This review is intended to guide practitioners on the initial evaluation and management of patients with short stature, and the indications for GH therapy.

Approach to the Patient: Safety of Growth Hormone Replacement in Children and Adolescents

The use of recombinant human growth hormone (rhGH) in children and adolescents has expanded since its initial approval to treat patients with severe GH deficiency (GHD) in 1985. rhGH is now approved to treat several conditions associated with poor growth and short stature. Recent studies have raised concerns that treatment during childhood may affect morbidity and mortality in adulthood, with specific controversies over cancer risk and cerebrovascular events. We will review 3 common referrals to a pediatric endocrinology clinic, followed by a summary of short- and long-term effects of rhGH beyond height outcomes. Methods to mitigate risk will be reviewed. Finally, this information will be applied to each clinical case, highlighting differences in counseling and clinical outcomes. rhGH therapy has been used for more than 3 decades. Data are largely reassuring, yet we still have much to learn about pharmaceutical approaches to growth in children and the lifelong effect of treatment.

Advances in differential diagnosis and management of growth hormone deficiency in children

Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000-10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care.

Long-Term Safety of Growth Hormone Treatment in Childhood: Two Large Observational Studies: NordiNet IOS and ANSWER

CONTEXT

Growth hormone (GH) treatment has a generally good safety profile; however, concerns about increased mortality risk in adulthood have been raised.

OBJECTIVE

This work aims to assess the long-term safety of GH treatment in clinical practice.

METHODS

Data were collected from 676 clinics participating in 2 multicenter longitudinal observational studies: the NordiNet International Outcome Study (2006-2016, Europe) and ANSWER Program (2002-2016, USA). Pediatric patients treated with GH were classified into 3 risk groups based on diagnosis. Intervention consisted of daily GH treatment, and main outcome measures included incidence rates (events/1000 patient-years) of adverse drug reactions (ADRs), serious adverse events (SAEs), and serious ADRs, and their relationship to GH dose.

RESULTS

The combined studies comprised 37 702 patients (68.4% in low-risk, 27.5% in intermediate-risk, and 4.1% in high-risk groups) and 130 476 patient-years of exposure. The low-risk group included children born small for gestational age (SGA; 20.7%) and non-SGA children (eg, with GH deficiency; 79.3%). Average GH dose up to the first adverse event (AE) decreased with increasing risk category. Patients without AEs received higher average GH doses than patients with more than one AE across all groups. A significant inverse relationship with GH dose was shown for ADR and SAE incidence rates in the low-risk group (P = .003 and P = .001, respectively) and the non-SGA subgroup (both P = .002), and for SAEs in the intermediate- and high-risk groups (P = .002 and P = .05, respectively).

CONCLUSIONS

We observed no indication of increased mortality risk nor AE incidence related to GH dose in any risk group. A short visual summary of our work is available (1).