Exp Clin Endocrinol Diabetes 2005; 113 - 151
DOI: 10.1055/s-2005-863010

Re-evaluation of the somatotropic axis in patients with childhood-onset GH deficiency during transition to adulthood

N Unger 1, BP Hauffa 2, K Mann 1, S Petersenn 1
  • 1University of Essen, Department of Endocrinology, Medical Center, Essen
  • 2University of Essen, Division of Endocrinology, Department of Pediatrics, Essen

Short stature due to growth hormone deficiency (GHD) is an indication for substitution with recombinant growth hormone (GH) until final height is reached. Since a significant proportion of all patients with isolated GHD has transient GHD, re-evaluation of GH secretory capacity is recommended at that time. This study compared the results of GH stimulation tests during childhood and adulthood in patients with childhood-onset GHD of various etiologies.

Sixteen patients (P) with impaired growth during childhood, diagnosed as GH deficient, were included: 4 P with morphological anomalies of the sellar region (MORPH) (2–3 additional pituitary deficiencies), 7 P after surgery or radiation of sellar masses (TU) (1–3 additional pituitary deficiencies) and 5 P with idiopathic pituitary dysfunction (IDEO) (0–1 additional pituitary deficiency). All responded with growth acceleration to recombinant GH substitution. Each patient was tested during childhood and retested after ≥ 6 months of GH discontinuation during adolescence. Peak GH levels for the insulin tolerance test (ITT) and one additional provocation test (PROV) both during childhood and adolescence were evaluated.

Using a GH cut-off of 10 ng/ml, all subjects had an inadequate response in at least one provocation test during childhood. Retesting using a cut-off of 3 ng/ml for the ITT revealed 100% of MORPH, 80% of TU and none of IDEO as GHD. Considering PROV tests, 100% of MORPH, 33.3% of TU and none of IDEO presented a GHD. Interestingly, two GHD patients with good growth response to GH substitution had a GH peak of 3–10 ng/ml during ITT in both childhood and adulthood. Due to the lower cut-off in adulthood, these patients would be not be considered anymore as having GHD.

Patients with morphological anomalies of the sellar region and patients after surgery of a sellar mass with at least 2 additional pituitary deficiencies had a persistent GHD during retesting in the adolescence. In contrast, patients with an idiopathic GHD revealed an adequate GH response to provocation tests during adolescence.