Hyperglycemia affects cardiovascular autonomic nerve function in normal subjects.

Abstract

To evaluate the effect of acute hyperglycemia on autonomic nerve function in normal subjects. Six healthy volunteers ages 19-32 years underwent paired studies during euglycemia (blood glucose 5.1 +/- 0.04 mmol/l) and hyperglycemia (blood glucose 15.7 +/- 0.48 mmol/l) induced by intravenous infusion of glucose and maintained for 150 min. The order of the two studies was randomized. In each experiment, supine heart rate, heart rate variation with respiration, ratio of the maximum to minimum R-R interval after standing ("30:15" ratio), systolic blood pressure response to standing, and diastolic blood pressure response to sustained handgrip were measured. Data were analyzed using repeated measures analysis of variance. The supine heart rate was greater (P = 0.04) and the "30:15" ratio less (P = 0.03) during hyperglycemia than during euglycemia. Hyperglycemia had no significant effect on any of the other cardiovascular reflex tests. These observations indicate that acute hyperglycemia affects autonomic nerve function in healthy humans.