EVIDENCE FOR PARTIAL GROWTH HORMONE (GH) INSENSITIVITY AMONG “IDIOPATHIC” SHORT STATURE (ISS) PATIENTS TREATED WITH GROWTH HORMONE

Abstract

Data from the NCGS shows that some patients with ISS (defined as a max. GH >10 ng/mL) have abnormally low GH-binding protein (GHBP) levels. Since low circulating levels of functional GHBP are found in patients with GH insensitivity syndrome, it is possible that these patients have partial GH insensitivity. There were 511 ISS patients in NCGS with GHBP measurements performed at baseline. Of these, 101 (20%) had GHBP SD scores ≤-2 compared to sex- and age-matched normal children. The table compares this group with the “normal-GHBP” group [mean±SD(n)]: There was a significant (p≤0.0001) linear correlation of GHBP SD score with IGF-I concentration (r=+0.28) and mean 12h GH concentration (r=-0.17). CONCLUSIONS: ISS patients with low GHBP levels, compared with those with normal GHBP levels, had lower IGF-I levels and higher mean 12h GH levels, suggesting partial GH insensitivity; however, the two groups had similar height SD scores and first year response to GH therapy.