Clinical trials of GH treatment in patients with Turner's syndrome in Japan--a consideration of final height. The Committee for the Treatment of Turner's Syndrome

Clinical trials of human GH (hGH) therapy in Turner's syndrome were started in 1986. Between 1986 and 1990. 362 patients were enrolled; 115 were treated for more than 6 years. The age at the start of treatment ranged from 5 to 18 years (mean 10 years). Fifty-one patients received hGH at a weekly dosage of 0.5 IU/kg and 64 received 1.0 IU/kg by daily s.c. injection. Both treatment groups showed a statistically significant growth increase during the initial 4 years of treatment. The rate of increase in height was significantly greater for the initial 2 years with the high dose than with the low dose. The increases in height over 6 years of treatment (expressed by S.D. score for chronological age) were 1.48 +/- 0.8 with 0.5 IU/kg per week and 1.80 +/- 1.0 with 1.0 IU/kg per week. To date, 260 patients have stopped GH therapy. In 32% of them, the height attained was above the -2 S.D. value for normal girls. In 27%, the growth rate was not sufficient when they stopped treatment. The mean final height (growth rate < or = 1.0 cm/year) of patients treated for more than 6 years was 142.2 +/- 6.5 cm (n = 15) with 0.5 IU/kg per week, and 144.3 +/- 3.9 cm (n = 15) with 1.0 IU/kg per week. The adult height was improved by GH treatment, although final height did not differ statistically between the two dose regimens. No remarkable adverse events occurred during the treatment. These results indicate that hGH treatment improves the final height in patients with Turner's syndrome.