ESPE Abstracts

Objective: We aimed to evaluate the relation between the peak growth hormone (GH) levels on provocative tests and response to recombinant human GH (rhGH) therapy in patients with GH deficiency (GHD).

Methods: This was a cross-sectional, single-center, and retrospective study. A total of 518 patients who received rhGH therapy under the age of 16 in the Endocrinology Clinic of Akdeniz University Hospital between 1997 and 2021 were identified through the hospital’s digital database system. Patients who had any genetic or chronic illness as well as using medication that may affect growth and patients diagnosed with GH neurosecretory dysfunction, GH resistance, acquired GHD due to radiotherapy/chemotherapy/surgery were excluded from the study. Finally, 135 subjects who were diagnosed with GHD by using insulin tolerance test and L-DOPA stimulation test and treated with rhGH for at least two years were included in the study.

Results: The patients were classified as group I (Idiopathic GHD, n=119) and group II (Multiple pituitary hormone deficiencies or having pathology on MRI, n=16). The idiopathic GHD patients were classified into 3 subgroups according to the peak GH values on the provocative tests (group Ia: peak GH < 3 μg/l, n=34; group Ib: peak GH between 3 - 7 μg/l, n=71; group Ic: peak GH between 7 - 10 μg/l, n=34). Height standard deviation score (SDS), Δheight SDS, and height velocity (HV) SDS were all higher in group Ia at the end of the 1^st year of the rhGH therapy (P=0.040, P=0.029, P=0.005). The height SDS was still significantly higher in group Ia (P=0.033) while the HV SDS and Δheight SDS were similar between the groups at the end of the 2^nd year of the therapy (P=0.164 and P=0.522). 1^st year HV SDS was significantly associated with midparenteral height SDS and peak GH value on provocative tests in multiple regression analyses (P=0.009, P=0.012).

Conclusion: It might be predicted that the lower the GH peak on provocative tests, the better the response to the treatment. The best HV is observed in the 1st year and the diagnosis should be checked in the patients who had low first-year HV and had not severely low GH peak on provocative tests.