Sympathetic response to oral glucose load is altered in hypertensive subjects.

Blood pressure, plasma norepinephrine (NE) and epinephrine (E) levels in responses to oral glucose load (OGTT) and to head-up tilting (Tilt) were measured in 14 hypertensive (HT) and 17 normotensive subjects (NT). In response to OGTT, NE significantly increased within 30 minutes (+25 +/- 8%; p less than 0.05) in NT, followed by a decline to the basal level, while it remained unchanged in HT (+5 +/- 8%). E decreased similarly during OGTT in both groups. Mean blood pressure, however, fell only in HT (-3.3 +/- 1.1%; p less than 0.05) but did not change in NT. Blood pressure, NE and E responses to Tilt did not differ between NT and HT. These results suggest that hypertensive subjects have some defects in sympathetic activation in response to glucose loading.