Final height of patients with Turner's syndrome treated with growth hormone (GH): Indications for GH therapy alone at high doses and late estrogen therapy

We report final height data of patients with Turner's syndrome collected by the Italian Study Group for Turner's Syndrome. One hundred and thirty-five patients reached their final height during GH therapy with different therapeutic regimens (dose and combination). They were divided into 3 groups: group A, 74 patients with high doses of GH (1 IU/kg/week) for at least 2 yr; group Al, GH alone and estrogen therapy added not before 14 yr of chronological age (47 patients, of whom 30 were treated for >4 yr and 10 for >6 yr); group A2, GH plus ethinyl estradiol(17 patients) or GH plus oxandrolone 110 patients); group B, 51 patients with low doses of GH (0.5 IU/kg week) and high doses of GH for less than 2 yr; and group C, 10 patients with high doses of GH with spontaneous menarche. In contrast to the patients of groups B and C, the patients of group A showed a significantly higher final height (mean, 147.5 +/- 6.5 cm) than their projected height (mean, 142.9 +/- 6.4 cm). They showed also a significantly higher final height compared to the subjects of groups B (mean, 145.6 +/- 5.7 cm) and C (mean, 143.0 +/- 5.3). Among the patients of group A, the best results were obtained in the patients of group Al treated with GH alone at high doses and for a longer period (4 yr, 149.3 +/- 6.4 cm; 6 yr, 153.8 +/- 4.0 cm). Karyotype, GH secretion, and birth weight did not influence the efficacy of GH therapy. A low target height and a high prevalence of a spontaneous ovarian activity or menarche may negatively influence the effect of GH therapy. Estrogens did not improve final height when added to GH therapy. The use of small doses of oxandrolone was not effective in our experience. GH therapy provides a satisfactory auxological result, especially with high doses of GH alone, given for a long period of time. Optimization of the treatment would seem to require the identification of the ideal age for starting therapy, and this is only possible with a specially designed multicenter study.