Detailed Investigation in Short Subjects allows a More Precise Indication for rhGH Treatment in Patients without Classic GH Deficiency

Growth is a frequent concern during adolescence. Although Normal Variant of Short Stature (NVSS) is the most frequent cause of borderline growth, more and more patients have been diagnosed as Partial Growth Hormone deficiency (PGHD) or Partial GH (PGHins) or IGF (PIGFins) insensitivity. These subjects should be considered as candidates to good response to rhGH therapy.

Aim: analyse Growth rate during the first year of GH treatment in PGHD-, PGHins-and PIGFins-patients.

Methods: 59 patients with short stature were included. Classic GH deficiency, chronic illness, genetic or nutritional disorders were excluded in all of then. Serum IGF-I levels were within normal range in all. Thirty-two were considered as NVSS and did not received rhGH; the others 27, some of them with advanced bone age and advanced pubertal stage, were divided in: PGHD (n=9), PGHins (n=9) and PIGFins (n=9) according to serum IGF-I concentrations and serum GH response to stimulation tests, and treated with rhGH. Anthropometric data were obtained before and 1-year after rhGH-treatment. Expected height velocity (HVexp), in case of no intervention, was estimated based on bone age and pubertal stage. HVexp was then compared to the real HV observed (HVreal).

Results: HVreal was similar to HVexp in the NVSS group but 73% higher than HVexp among treated patients.HVreal was74% higher than HVexp in the DGHD-group, 56% higher than HVexp in the PGHins-group and 85% higher than HVexp in the PIGFins-group. Improvements in height-SDS and in estimated final height were also observed among treated patients. The younger the patient the more pronounced improvement in growth parameters.

Conclusion:PGHD-, PGHins-, PIGFins-patients showed good improvement in growth parameters during rhGH-treatment. Effort in identifying these conditions should be made in order to introduce rhGH therapy as early as possible. A longer follow-up is necessary to evaluate the real impact on final height.