DECREASED INSULIN SENSITIVITY AND COMPENSATORY HYPERINSULINEMIA AFTERHORMONE-TREATMENT IN CHILDREN WITH SHORT STATURE

To assess the effects of GH treatment on carbohydrate and protein meta bolism, we studied eight patients with short stature before and after the commencement of GH treatment. The hyperglycemic clamp procedure wa s employed to produce a hyperglycemic stimulus of 50 mg/dL above fasti ng levels for 120 min. These patients were then treated with 0.3 mg/kg .week GH for 6 months, after which they were restudied. Patients were compared to-eight healthy control children matched for age, sex, and T anner stage. Pasting plasma glucose did not change significantly, but fasting plasma insulin levels were higher after GH therapy (P < 0.005) . Despite identical glucose increments during the glucose clamp proced ure, both first and second phase insulin responses were markedly great er after instituting GH treatment. Even in the face of higher mean pla sma insulin levels after GH treatment, the rate of insulin-stimulated glucose metabolism did not differ during the last 60 min of both studi es. Hence, the rate of insulin-stimulated glucose metabolism/mean plas ma insulin ratio (an index of insulin sensitivity) was sharply reduced after GH treatment (P < 0.01). During the clamp, the fall in circulat ing branched chain amino acid levels was significantly greater after G H therapy (P < 0.02). We conclude that glucose-stimulated insulin resp onses are increased in short children treated with GH and that such hy perinsulinemic responses compensate for reductions in insulin sensitiv ity. The compensatory hyperinsulinemic responses induced by GH therapy may serve a beneficial role by augmenting insulin's anabolic effects on protein metabolism.