Insulin sensitivity in Turner's syndrome: influence of GH treatment

Excessive GH secretion may lead to secondary diabetes mellitus, while prolonged GH treatment may accelerate the onset of type 2 diabetes mellitus in predisposed individuals. Turner's syndrome (TS) patients are a population at risk since they have reduced glucose tolerance (GT) spontaneously and because they are usually treated with high doses of GH.

The aim of the study was to evaluate insulin sensitivity (IS) and glucose tolerance (GT) in a group of TS patients treated with GH for a period of 6 years. Forty-seven TS girls were included in the study. GH was administered at a mean weekly dosage of 0.35 mg/kg, injected subcutaneously over 6-7 days. GT was assessed according to the criteria of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. IS was evaluated with the quantitative insulin sensitivity check index (QUICK-I).

No significant increase of impaired GT was observed in the patients during the follow-up period, while a reduced IS was detected. IS in TS patients was already lower than in prepubertal controls (P<0.001) before starting treatment and further decreased during the first year of therapy (P<0.05), and then remained stable over the following years. No correlation was found between QUICK-I, body mass index, years of treatment, onset and duration of puberty. One patient became diabetic during the course of treatment.

GH treatment in TS girls does not significantly increase the prevalence of impaired GT or type 2 diabetes mellitus, while it does, however, decrease IS.