Acute metabolic effects of human growth hormone on N-15-nitrogen balance in patients with thalassaemia as compared to patients with other types of short stature

The acute response to various doses of human growth hormone (hGH) was deter mined in short patients with thalassaemia and compared to that in patients with classic growth hormone deficiency and Turner's syndrome. Nitrogen bala nce was analyzed using the stable isotope N-15. While patients with growth hormone deficiency responded with a marked nitrogen retention (+2.9 +/- 0.4 to +6.1 +/- 0.6 mg N-15/kg) to small doses of hGH (2 x 3 IU/m(2)), those w ith Turner's syndrome had a higher basal balance, but responded much less ( +3.1 +/- 0.7 to +3.7 +/- 1.8 mg N-15/kg), They required a double dose of hG H (2 x 6 IU/m(2)) to achieve a significant retention (+4.1 +/- 1.0 to +7.1 +/- 0.4 mg N-15/kg), The thalassaemic patients responded still Less than th e patients with Turner's syndrome to 2 x 6 IU/m2 (+7.7 +/- 0.3 to +8.0 +/- 0.4 mg N-15/kg), and even hGH doses up to 2 x 12 IU/m(2) had little effect, indicating a relative resistance to hGH, In conclusion, no or little effec t is to be expected from long-term hGH treatment at low doses in thalassaem ic patients. When it is decided to treat these patients, the dose should be about 4 times higher than a regular replacement dose in growth hormone def iciency.