Adrenomedullary hyperactivity in type I diabetic patients before and during continuous subcutaneous insulin treatment

Urinary norepinephrine (NE) and epinephrine (E) excretion was measured at 4-h intervals for 2 consecutive days in nine type I diabetic patients with no signs of autonomic neuropathy before and after 3 weeks of glycemic control with continuous insulin infusion (CSII). Twenty-four-hour urinary E excretion was significantly higher in the diabetic patients than in normal subjects both before and after the period of CSII treatment [mean, 198.9 +/- 20.6 +/- SE and 127.8 +/- 24.4 vs, 46.6 +/- 9.8 nmol/day; P less than 0.05 for both]. The values in each of the 4-h periods before and in two of three of the periods after the 3-week period of CSII were significantly higher than those in normal subjects. Total urinary NE excretion was similar to that in the normal subjects at both times. The 24-h urinary NE/E ratio was significantly lower in diabetic patients even after they had achieved good metabolic control, compared with that in normal subjects (1.4 +/- 0.2 vs, 11.6 +/- 3.7; P less than 0.03). These data demonstrate hyperactivity of the adrenal medulla in type I diabetic patients, which is only partially reversed by a short period of glycemic control.