PSAT107 Evaluating Pituitary Volume and the Growth Hormone Stimulation Test in Siblings. Both Together Better Define the Etiology of Short Stature.

Abstract We have shown that short children have significantly reduced pituitary volume (PV)s and have speculated PV as a cause for diminished chronic growth hormone (GH) secretion and poor growth. In this study, we further elucidate the role of PV in the etiology of short stature (SS) in a larger cohort of siblings (SBs).The database of a Peds Endo Center between 2013-21 was queried for siblings with SS who underwent a GH Stimulation test (GHST) and MRI evaluation. Their results were compared with normal controls (NCs) as previously reported. 129 SBs of 60 families were compared to 170 NCs. SBs were divided into 3 groups (GPs). GP1 (n=79) consisted of families with only GHD. GP2 (n=12) contained families with only ISS SBs. GP3 (n=38) comprised families with mixed GHD and ISS. SBs <11 yrs and >11 yrs were considered prepubertal (prePB) and pubertal (PB), RSP. The mean (MN) and median (MD) age for both prePB and PB SBs were significantly different (p 0.05). The 32 PB patients in GP3 had a mean PV of 316.17± 197.53 mm3, which was significantly different from that of the PB NCs of 424.6 ± 138.4 mm3 (p<0.001). Out of 38 children in GP3, 18 passed the GHST and 11 of those children who passed demonstrated a small pituitary gland (61%). 78% of prePB SBs had small PVs, while 88% were GHD. 66% of PB SBs had small PVs, while 70% of PB SBs were GHD. 71% of all SBs had small PVs, while 77% were GHD. When combined, GHST and PV identify the etiology for SS in 92% of subjects. The GHST and PV together identify more patients of SS who should qualify and benefit from GH therapy than the GHST alone. Since ages were significantly different and present as a limitation to this study, future studies should strive for age match control Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.