ESPE Abstracts

Objectives: To reassess growth hormone (GH) status by the means of Insulin (ITT) and Glucagon tests (GL) in young adults with childhood-onset GHD.

Methods: We present preliminary data of 67 subjects (25F, 42M) recruited from a single Center, in whom anthropometrics, ITT and GL stimulation tests and IGF-1 evaluations were undertaken at adult height achievement, at a mean age of 17.3±2.2 (range: 13.3-25.7). Subjects were classified as idiopathic isolated GHD (I-GHD n = 33), organic GHD (0, 1 or 2 hormone deficiencies=O-GHD, n = 18), congenital/genetic defects/organic GHD (≥3 hormone deficiencies, CGO-GHD, n = 16) based on the American Association of Clinical Endocrinologists guidelines 2019. Diagnosis of permanent GHD was compatible with a peak GH value <6μg/l after ITT.

Results: GH peak to ITT (1.7±1.7 μg/l) and GL (1.7±1.7 μg/l, range 0.0-5.3) were lower in CGO-GHD compared to I-GHD subjects (19.4±10.8 to ITT and 15.1±6, range 5.3-31.5 μg/l to GL, P’s <0.0001); similarly, GH peak to ITT (3.7±4.3 μg/l) and GL (4.2±5.3 μg/l, range 0.4-17.8) were lower in O-GHD compared to I-GHD subjects (P’s <0.0001). Mean IGF-1 were also lower in CGO-GHD (-3.2±2.3 SDS; P < 0.0001) and in O-GHD (-2,0±1.6 SDS; P < 0.0001) compared to I-GHD subjects (0.1±1.1 SDS). In contrast, there were no differences in GH peak responses to ITT or GL and IGF-1 SDS values between O-GHD and CGO-GHD. A GH peak <6 μg/l for ITT was found in 29/67 of whom 13 O-GHD (72% of O-GHD) and 16 CGO-GHD (100% CGO-GHD); a GH peak <5.4 μg/l after GL was obtained in 31/67 of whom 14 O-GHD (77% of O-GHD), 16 CGO-GHD (100% CGO-GHD patients) and 1 I-GHD patient (GH peak to GL 5.26 μg/l, to ITT 7.13 μg/l; 3% I-GHD). Mean BMI SDS was higher in patients with CGO-GHD (1.2±1.4, P < 0.001) and O-GHD (1.1±1.0, P < 0.001) compared to I-GHD (-0.2±1.2). GH peak to glucagon was not correlated with BMI SDS (all P’s n.s.).

Conclusions: Our preliminary results suggest that GL test is accurate in detecting CGO-GHD during transition independently of BMI SDS.