Interrelationship between insulin, leptin and growth hormone in growth hormone-treated children

OBJECTIVES: The aim of the study was to examine insulin homeostasis during growth hormone (GH) therapy, and to investigate the effect of GH treatment on insulin and leptin concentration in obese children. SUBJECTS: Nineteen obese children (8 with Prader-Willi Syndrome (PWS)) were treated with GH 0.1IU/kg/day dose for 3 months and were compared with 29 n on-treated age and sex matched obese children (9 PWS) and 49 GH treated non -obese short children. Mean age of the children was 10.3 +/- 1.8 (6.7 - 1 3 .8) y, with body mass index of 23.6 +/- 1 0.4 (11.5 -47) kg/m(2) RESULTS: leptin concentration decreased acid was correlated inversely with initial leptin value (r(2) = - 0.374, P < 0.001) and decreased body mass (r (2) = 0.338, P= 0.001). Insulin sensitivity index was not significantly cha nged during therapy. Leptin decrease after 3 months of GH administration wa s correlated inversely with the increase in first phase insulin response to intravenous glucose tolerance test (IVGTT) (r(2)=-0.595, P < 0.001). Resul ts of long-term follow-up of treated patients demonstrated a decrease in in sulin concentration after cessation of therapy. In GH-treated subjects, the glucose increase in response to glucose load appeared to be higher than in untreated subjects. CONCLUSION: The high insulin response to glucose load seen in GH-treated su bjects was appropriate to their glucose concentration and the insulin sensi tivity index was unchanged relative to the pretreatment period. Increased i nsulin dosage in our patients did not induce an increase in leptin concentr ations as had been hypothesised.