Growth-stimulating effects of human growth hormone therapy in patients with Turner syndrome

We determined the effect of pituitary human growth hormone treatment on the growth rate of 52 children with Turner syndrome. The pretreatment growth rate was 3.2 +/- 0.8 cm/yr. Growth hormone treatment (0.2 IU/kg three times per week) resulted in enhancement of the growth rate to 5.9 +/- 1.4 cm/yr for the first year of therapy. The bone age advanced approximately 1 year during the year of therapy. The growth hormone therapy was discontinued at 12 months, and the mean growth rate decreased to pretreatment levels, 3.1 +/- 1.9 cm/yr; 26 of 41 patients actually had post-treatment growth rates that were less than the pretreatment rate. Glucose tolerance tests at 6-month intervals did not indicate an effect of hGH treatment on glucose intolerance. Several patients had glucose intolerance that preceded hGH treatment, but this remained stable during treatment; glucose intolerance likely was related to obesity in this group of patients. Basal and hGH-stimulated somatomedin C levels (32 patients) correlated with age of the patient but not with growth rate during therapy. We conclude that hGH therapy can accelerate the growth rate of patients with Turner syndrome. The growth rate increased to "normal" levels and was dependent on continued treatment with hGH. If the response continues, long-term treatment of Turner syndrome may result in increased adult height.