Gradually increasing ethinyl estradiol for Turner syndrome may produce good final height but not ideal BMD

[Abstract.] Estrogen replacement therapy in Turner syndrome should theoretically mimic the physiology of healthy girls. The objective of this study was to describe final height and bone mineral density (BMD) in a group of 17 Turner syndrome patients (group E) who started their ethinyl estradiol therapy with an ultra-low dosage (1-5 ng/kg/day) from 9.8-13.7 years. The subjects in group E had been treated with GH 0.35 mg/kg/week since the average age of 7.4 years. The 30 subjects in group L, one of the historical groups, were given comparable doses of GH, and conjugated estrogen 0.3125 mg/week ～0.3125 mg/day was initiated at 12.2-18.7 years. The subjects in group S, the other historical group, were 21 patients who experienced breast development and menarche spontaneously. Final height (height gain < 2 cm/year) in group E was 152.4 +- 3.4 cm and the standard deviation (SD) was 2.02 +- 0.62 for Turner syndrome. The final height in group L was 148.5 +- 3.0 cm with a SD of 1.30 +- 0.55, which was significantly different from the values for group E. The volumetric BMD of group S (0.290 +- 0.026 g/cm3) was significantly different from that of group L or E (0.262 or 0.262 g/cm3 as a mean, respectively). This is the first study of patients with Turner syndrome where estrogen was administered initially in an ultra-low dose and then increased gradually. Our estrogen therapy in group E produced good final height but not ideal BMD.