TIMING OF GH PEAK IN BOTH GLUCAGON AND CLONIDINE TESTS IS OF MAJOR CLINICAL IMPORTANCE

Abstract Objective: To detect a possible correlation between timing of the peak value of GH during STs and the effectiveness of treatment with rhGH in children with idiopathic GH deficiency (iGHD). Methods: We retrospectively studied 92 patients with iGHD (57 boys, mean age at diagnosis: 9.93 years). Diagnosis was confirmed by 2 different STs, GST and clonidine stimulation test (CST). Auxological parameters were recorded, while observed and predicted (according to KIGS Prediction Model) height velocity (HV) during the first year of treatment and the index of responsiveness IoR were calculated for the prepubertal children (n=65). Results: Atypical GST was defined as that with peak GH value at time 0′, 30′, 60′ or 180′ whereas atypical CST as that with peak timing at 0′, 30′ or 120′. Atypical GST was detected in 18 patients (19.57%). IoR was lower in the prepubertal children with atypical GST (−1.81±0.67 vs −1.34±0.85 p=0.051). In the CST the 18 children who had atypical timing, had significantly lower lowe...