The role of growth hormone in the glucose intolerance of uremia

Summary

The fasting plasma growth hormone (GH) concentration and the plasma growth hormone response to sustained hyperglycemia was examined in 8 chronically uremic subjects before and after hemodialysis employing the hyperglycemic clamp technique. The plasma glucose concentration was actuely raised and maintained at +125 mg/100 ml above basal levels. Since the glucose concentration was held constant, the glucose infusion rate is an index of glucose metabolism (M) and M divided by the plasma insulin response (I) is a measure of tissue sensitivity to insulin. Predialysis, the fasting GH concentration, 4.0±1.0 ng/ml, was significantly greater than controls, 0.3±0.1 ng/ml (p<0.01), and failed to suppress normally following sustained hyperglycemia. Both M, 4.23±0.36 mg/kg·min, and M/I, 5.05±0.79 mg/kg·min per µU/ml, were significantly reduced compared to controls (p<0.001). There was no correlation between either the fasting GH concentration or the GH response to sustained hyperglycemia and either M or M/I. Following dialysis both M, 6.30±0.64 mg/kg·min, and M/I, 8.39±1.06 mg/kg·min per µU/ml, increased (p<0.01) without significant change in either the fasting GH level, 4.0 ± 1.2 ng/ml, or the plasma GH response to hyperglycemia. It is concluded that while deranged GH physiology is a common accompaniment of the uremic state, it is not responsible for the glucose intolerance and tissue insensitivity to insulin observed in uremia.