Growth hormone deficiency and the transition from pediatric to adult care

Predictive Factors of Persistent Growth Hormone Deficiency and Impact on Final Height

BACKGROUND/OBJECTIVES

Recombinant growth hormone (rhGH) treatment plays an important role in the transition phase in those subjects diagnosed as having persistent growth hormone deficiency (GHD). We aimed to identify the main predictors of persistent GHD in a large cohort of subjects with childhood-onset GHD who underwent retesting and their correlation with height gain and mid-parental height (MPH).

METHODS

Anthropometric data, such as growth rate; bone age (BA); IGF-1 SDS at the start, at 1 year, and at the end of rhGH therapy; GH peak at diagnosis and at retesting; brain Magnetic Resonance Imaging (MRI) at diagnosis; and height gain upon reaching final height (FH) and compared to MPH, were obtained from medical records of GHD patients.

RESULTS

Persistent GHD was detected in 37 out of 91 (40.7%) GHD subjects. In univariate analysis, persistent GHD was associated with growth rate at 1 year (p = 0.0117) and with the first test GH peak (p = 0.0290). In the regression analysis, persistent GHD was positively associated with growth rate at 1 year (p = 0.0294) and negatively with female gender (p = 0.0424). Height gain was positively associated with growth rate (p = 0.0010) and with age at onset (p = 0.0021), while an inverse association with BA at baseline (p = 0.0002) and IGF-1 SDS (p = 0.0321) was found.

CONCLUSIONS

Our study confirmed that the most important predictor of persistent GHD is the growth rate in the first year of therapy. Furthermore, growth rate in the first year, female gender, and lower BA at diagnosis are predictors of rhGH efficacy both in terms of height gain and target height achievement.

Growth hormone signaling and clinical implications: from molecular to therapeutic perspectives

Growth hormone (GH) is a key polypeptide hormone secreted by somatotroph cells in the anterior pituitary gland, essential for postnatal growth, metabolism, and systemic homeostasis. Its secretion is regulated by hypothalamic neuropeptides, including GH-releasing hormone and somatostatin. GH exerts effects through direct interaction with the growth hormone receptor and indirect pathways mediated by the GH-IGF-I axis. GHR activation triggers signaling pathways, such as JAK-STAT, PI3K/AKT, and MAPK, promoting cellular proliferation, differentiation, and metabolic balance. The GH-IGF-I axis is critical for bone growth, lipid and carbohydrate metabolism, and organ-specific physiological functions. Dysregulation of GH results in diverse disorders. Congenital deficiencies, like isolated GH deficiency and syndromic conditions (e.g., Turner syndrome), stem from genetic mutations. Acquired deficiencies arise from trauma, tumors, infections, or autoimmune damage, while GH overproduction causes gigantism in children and acromegaly in adults, often due to pituitary adenomas. Idiopathic deficiencies, lacking identifiable causes, complicate management further. Advances in therapy have transformed outcomes for GH disorders. Recombinant human growth hormone provides effective replacement therapy for deficiencies. Somatostatin analogs, dopamine receptor agonists, and GH receptor antagonists are pivotal for managing GH excess. Surgical and radiotherapeutic interventions remain essential for pituitary adenomas. However, GH therapy requires close monitoring to prevent side effects like insulin resistance and metabolic complications. This review provides a comprehensive evaluation of the molecular mechanisms underlying GH action, its physiological roles, GH-related disorders, and therapeutic approaches to optimize patient outcomes.

Transition Period and Young Adulthood in Patients with Childhood Onset Growth Hormone Deficiency (COGHD): Impact of Growth Hormone Replacement on Bone Mass and Body Composition

The aim of this review article is to highlight the consequences of COGHD after the end of linear growth on bone mass and body composition and the opposing beneficial effects of continuing GH replacement in the transition period and young adults. The role of growth hormone in the period of late adolescence and young adulthood is well established, mainly in achieving peak bone mass and a favorable body composition, characterized by muscle mass increase and fat mass reduction. Patients with childhood onset growth hormone deficiency (COGHD), after reaching the adult height, have a reduced bone mineral density and muscle mass with increased fat mass compared to healthy controls. Inadequate body composition is a predictor for cardiovascular risk, while low bone mass in early youth hallmarks the risk of osteoporosis and bone fractures in later life. Cessation of growth hormone replacement (GHr) after completion of growth will lead to delayed peak bone mass and unbalanced body composition with increased abdominal fat deposits. According to numerous clinical studies monitoring the effects of GH treatment on the physical and psychological status of patients with persistent GHD after completion of growth, we suggest continuing this treatment between 16 and 25 years of age. It is advised that GHr in the transition period be administered in intermediate doses between those for the pediatric population and those for the adult population. Usual daily GHr doses are between 0.3 and 0.5 mg but need to be individually optimized, with the aim of maintaining IGF-I in the age-specific normal range.

[Management of transition growth hormone deficiency]

With an increasing understanding of growth hormone deficiency, there has been a growing emphasis on the management of transition growth hormone deficiency (TGHD) in clinical practice. The inadequate diagnosis and treatment of TGHD have been a major clinical concern, leading to the development of relevant guidelines and consensus internationally. This article summarizes the evaluation, diagnosis, treatment, and clinical challenges of TGHD based on these guidelines, consensus, and existing clinical studies, aiming to optimize and further improve the clinical diagnosis, treatment, and management of TGHD.