Insulin antagonistic effects of growth hormone in short children.

Growth hormone has several insulin antagonistic effects. To determine the time course of these effects in growth-hormone-treated children, the frequently samples intravenous glucose tolerance test was used to measure insulin sensitivity (SI) and glucose effectiveness (Sg) before, and 1 week, 1 month and 6 months after beginning growth hormone therapy in 3 patients with growth hormone deficiency (GHD), 3 patients with non-growth-hormone-deficient short stature (NGHD) and 3 with Turner syndrome (TS). Pretreatment SI was lower in TS than in the other two groups (p < 0.05), but Sg did not differ between groups. Mean SI levels 1 week and 1 month after starting growth hormone therapy were not different from before growth hormone [1.67 +/- 0.26 x 10(-4) (pmol/l)-1 min-1]. SI after 6 months of growth hormone [0.67 +/- 0.15 x 10(-4) (pmol/l)-1 min-1] was lower than before and 1 week after growth hormone (p < 0.005). SI responses did not differ between groups. Sg, glucose tolerance, blood pressure, triglyceride, and cholesterol levels did not change, but the incremental insulin response increased with growth hormone therapy. Thus, in this small study 6 months of growth hormone therapy decreased SI, but did not affect other cardiovascular risk factors.