Auxologic parameters and response to 2-year therapy with recombinant human growth hormone in growth hormone deficient children with an ectopic posterior pituitary.

BACKGROUND Structural defects of the hypothalamic-pituitary area in MRI are suggested as being a more accurate marker of growth hormone deficiency (GHD) than laboratory assays. OBJECTIVE To compare auxological characteristics in GHD children with normal pituitary (NP) function and with ectopic posterior pituitary (EPP), prior to therapy with recombinant human growth hormone (rhGH), extending the follow-up to two years following treatment. DESIGN Eighty-six (86) GHD patients were divided into two groups depending on the pituitary MRI: the EPP (23 children, 3.2-16.8 years old) and the NP group (63 children, 3.3-14.8 years old). Height deficits in the population (hSD) and parents (hSD-mpSD) and the change of hSD and bone/chronological age ratio were assessed before and after 12 and 24 months of rhGH therapy. RESULTS Height deficits before treatment were significantly greater in EPP compared to NP [median -4.07 (-7.06, -2.75) vs -3.15 (-4.9, -2.35) for hSD, and -3.65 (-7.06, -1.21) vs -1.83 (-4.31, -0.28) for hSD-mpSD; p<0.05]. Bone age was significantly delayed in the EPP group [0.62 (0.27, 0.92) vs 0.75 (0.21, 0.71); p<0.05]; differences remained significant during follow-up. After 12 months of rhGH therapy, EPP showed significantly greater catch-up growth compared to NP [ΔhSD=1.2 (0.42, 2.69) vs 0.74 (0.05, 1.48); p<0.05]. In the 2nd year, height velocity slowed down and was comparable in the two groups. At the conclusion of the study, hSD was similar in both groups, but hSD-mpSD was more deviated in EPP [-1.79 (-3.71, -1.21) vs -1.1 (0.98, -0.07); p<0.05]. CONCLUSIONS The study showed relevant auxologic differences between EPP and NP children, as well as beneficial effects of rhGH therapy in both groups.