IMPE Abstracts

Transition is an opportunity for reassessment of pituitary defects of childhood-onset and the need for lifelong replacement therapies. However, although the existing guidelines have described how to re-evaluate GHD during transition, there is no clear plan in many countries about the delivery of transitional care from pediatric to adult services. In particular, GH plays a crucial role not only for growth, but also for the acquisition of bone mass and muscle strength. Thus, continuation of GH replacement therapy in the transition age is essential in patients with permanent GHD, and careful evaluation of pituitary function for possible evolving pituitary defects is essential. Higher likelihood of persistence is observed in patients with an early age at diagnosis, anatomical, organic, or genetic causes, and MPHD. Repeating a GH stimulation test is not necessary for patients with MPHD (≥3 PHD) and low-serum IGF-1 concentrations (<–2.0 SDS), in patients with documented genetic defects affecting pituitary function, and in patients with hypothalamic-pituitary structural brain defects. In these cases, rhGH therapy can be continued without interruption, although the dose should be reduced to the adult age dose. Indeed, patients with idiopathic IGHD and an IGF-1≥0 SDS are not likely to have persistent GHD, and thus transition may not be necessary. There is still controversy about which limit for a normal GH response should be considered for the transition age group, and the lack of strong evidence leads to variable clinical practice. According to the last Consensus of 2019, the ITT remains the gold-standard test for establishing the diagnosis of young adult GHD using a peak GH cut-point of ≤5.0 µg/L, while according to others the optimal GH cut-off value after adult height achievement is 6 µg/L. While recent data have suggested that combined GHRH and arginine is unreliable and may fail to recognize patients with permanent GHD of different etiologies, it should be emphasized that the validated normative data of glucagon-stimulation test and macimorelin in transition age are still lacking.

Learning points

1. Share the pros and cons of testing and discuss the proper assessment of hypopituitarism after adult height achievement

2. Gain more confidence in key predictors of persistent GHD

3. Discuss the clinical implications of diagnostic and management processes with a particular focus on needs and outcomes through transition