LACK OF EFFECT OF HYPERGLYCEMIA ON LIPOLYSIS IN HUMANS

To examine whether hyperglycemia is an independent regulator of adipos e tissue lipolysis, we measured palmitate flux ([H-3]Palmitate) on two occasions in eight volunteers with insulin-dependent diabetes. On one occasion, euglycemia was maintained for 4 h continuously; on a differ ent occasion, hyperglycemia (plasma glucose, 12 mmol/l) was induced af ter 2 h of euglycemia. Palmitate flux decreased from 1.39 +/- 0.22 to 1.25 +/- 0.18 mumol . kg-1 . min-1 during sustained euglycemia and fro m 1.43 +/- 0.24 to 1.13 +/- 0.19 mu/mol . kg-1 . min-1 during the tran sition from the euglycemic to the hyperglycemic study intervals. There were no significant differences between the changes in palmitate flux from the first to the second study interval on the control (euglycemi a-euglycemia) and experimental (euglycemia-hyperglycemia) study days a nd no difference between palmitate flux on different study days. Thus, in the face of euinsulinemia, euglucagonemia, and the absence of soma tostatin, no effect of hyperglycemia on free fatty acid metabolism cou ld be detected in humans.