Glucose tolerance and insulin sensitivity in Turner patients treated with GH: Follow-up until the young adult age

Insulin resistance and impaired glucose tolerance, considered one of the risk factors of cardiovascular diseases, have been reported as an early metabolic defect in Turner patients. Short stature is one of their main clinical features and GH-therapy improves the final height. The interaction between GH and glucose tolerance is well known. The aim of our study was to evaluate the effects of GH on glucose tolerance and insulin sensitivity during GH-therapy (3.0-10.7 yrs) and after suspension (3-9 yrs). A female matched control group was considered. A group of 47 patients with Turner syndrome that reached the final height with GH-therapy at high doses (0.33 mg/kg/week) were investigated for insulin sensitivity and b-cell function with fasting measurements (HOMA-R, HOMA-S, QUICKI, fasting insulin, glucose0'/insulin0') and OGTT (insulinogenic index (IGI) 30', IGI 120', Matsuda and OGIS index). Turner patients had lower values in insulin sensitivity indices before, during and after GH-therapy than controls. During GH-therapy these values decreased slightly, returning to pre-treatment levels after suspension. The indices were negatively correlated with BMI and triglyceride levels, and positively with GH-duration. Patients with X- structural abnormalities had a greater degree of insulin resistance. Concluding, Turner pts showed a lower insulin sensitivity than controls. GH-therapy determined a slight lowering of insulin sensitivity. We noted an adaptation to long periods of GH-therapy and after suspension insulin sensitivity returned to pre-therapy levels. This increase was influenced negatively by BMI and triglyceride levels. Insulin resistance was higher in the patients over 12 years than in the younger patients. Estrogen therapy appeared to have a slight negative effect on insulin sensitivity.