Growth-promoting effect of growth hormone and low dose ethinyl estradiol in girls with Turner's syndrome.

Forty patients with Turner's syndrome, aged 5.0-16.6 yr, were randomly allocated to receive daily sc injections of recombinant human GH (hGH) at a dose of 1 IU/kg.week alone (group I) or in combination with 25 ng/kg.day ethinyl estradiol (E2; group II). The mean pretreatment height velocity was 3.8 cm/yr for both groups. During the first year of treatment height velocity increased significantly (P less than 0.001) in both groups, to 7.5 +/- 1.3 and 8.1 +/- 1.6 cm/yr, respectively. The difference between the two groups was not significant. The mean (+/- SD) height velocity expressed as the SD score for chronological age (Turner references) was 0.0 +/- 1.2 for group I and 0.2 +/- 1.4 for group II and increased significantly (P less than 0.001) during the first year of treatment to +4.3 +/- 1.1 in group I and +5.4 +/- 1.2 in group II. The difference between both groups was statistically significant (P less than 0.01). Height SD score for chronological age (Turner references) increased from -0.2 +/- 0.9 to +0.6 +/- 1.0 in group I and from -0.2 +/- 1.0 to +0.7 +/- 1.1 in group II. Mean bone age progressed similarly in both treatment groups (1.1 +/- 0.6 yr during 1 yr of treatment). However, bone age maturation accelerated more rapidly in younger patients. Twelve girls (three in group I and nine in group II) had minor breast development. No major adverse effects were reported. We conclude that daily sc therapy with hGH stimulates height velocity in Turner's syndrome. The beneficial effect on height velocity increment of E2 addition was small. Furthermore, even very low doses of E2 may induce breast development at an early age and accelerate bone maturation. For these reasons, the addition of E2 to hGH is not warranted in young patients with Turner's syndrome.