Objective: There have been few studies of GH dose responses in Turner's syndrome. We have therefore compared the growth effect of two doses of subcutaneous GH: 0.45 (D1) or 0.90 (D2) IU/kg/week.
Design: Multicentre study with two parallel randomized groups treated with D1 or D2 dose for one year, then with D2 for the second and third years in both groups.
Patients: Ninety-seven girls with Turner's syndrome aged from 4.8 to 16.5 years.
Results: The first mean height velocity (HV) was significantly higher with D2. At one year the girls changed from D1 to D2 showed a further acceleration in HV. During second and third years HV remained above the mean for untreated Turner girls, in both groups. Mean cumulative height gains over the 3 years were 1.06 and 1.17 SDS/CA (Ranke's Turner standard) in groups G1 and G2 respectively. Bone maturation, over 36 months, was 33.7 (G1) and 31.9 (G2) months.
Conclusion: These results suggest that, if a higher initial GH dose is associated with a greater net initial height gain, the duration of treatment might affect the long-term results. Intermittent treatment should be considered.