Effects of Growth Hormone on Growth, Insulin Resistance and Related Hormones (ghrelin, Leptin and Adiponectin) in Turner Syndrome

Background: Concomitant evaluation of the metabolic and growth-promoting effects of growth hormone (GH) therapy in Turner syndrome (TS) may be used in the prediction of the growth response to GH therapy.

Aim: To evaluate the metabolic effects of GH therapy in TS and correlation with the short-term growth response.

Patients: 24 prepubertal children with TS, aged 9.4 +/- 2.6 years were followed for auxology and IGF-I, IGFBP-3, leptin, ghrelin, adiponectin, lipids and OGTT results in a prospective multicenter study.

Intervention: GH (Genotropin) in a dose of 50 microg/kg/day for 1 year.

Results: Height standard deviation score (SDS) increased from -3.9 +/- 1.5 to -3.5 +/- 1.4 (p = 0.000) on therapy. BMI did not change. IGF-I SDS increased from -2.3 +/- 0.4 to -1.6 +/- 1.1 at 3 and 6 months (p = 0.001) and decreased thereafter. Serum leptin decreased significantly from 2.3 +/- 3.9 to 1.7 +/- 5.3 ng/ml (p = 0.022) at 3 months and increased afterwards. Serum ghrelin decreased from 1.2 +/- 0.8 to 0.9 +/- 0.4 ng/ml (p = 0.005) with no change in adiponectin. Basal and stimulated insulin levels also increased significantly. Delta height SDS over 1 year showed a significant correlation with Delta IGF-I(0-3 months) (r = 0.450, p = 0.027).

Conclusion: IGF-I may be considered as a marker of growth response in TS at short term. Leptin shows a decrease at short term but does not have a correlation with growth response. The decrease in ghrelin in face of unchanged weight seems to be associated with increase in IGF-I and insulin levels. The unchanged adiponectin levels in spite of an increase in insulin levels indicates that adiponectin is mainly affected by weight, not insulin.