Increased plasma norepinephrine concentrations and metabolic rates following glucose ingestion in man

The effects of glucose ingestion on plasma levels of norepinephrine (NE), epinphrine (E), immunoreactive insulin (IRI), and glucose, and the resting metabolic rate (RMR) were examined in six normal males. Ingestion of the glucose (100 g) solution significantly increased all of these measures except E levels, compared with changes observed during a control experiment in which an equal volume of water was ingested. The initial (0-60 min) increase in plasma NE levels and the increase in the RMR following glucose was significantly greater than the smaller increases that occurred during the control experiment. Plasma IRI and glucose levels peaked 30-60 min after glucose consumption, then declined toward basal values. These data show that glucose intake causes an elevation of the RMR and sympathetic nervous system activity greater than that caused by other aspects of the testing solution, and are consistent with the possibility that the increase in RMR following glucose ingestion is related to elevated sympathetic nervous system activity.