DECREASED SYMPATHOADRENAL ACTIVITY IN DIABETIC-PATIENTS WITH AUTONOMIC DYSFUNCTION FOLLOWING MENTAL STRESS

The sympathetic nervous system is of major importance in the regulatio n of numerous physiological functions. While it is clearly established that there is a decreased noradrenergic status in people with autonom ic neuropathy, the epinephrine secretion is much mon controversial. Ba sal and mental stress-stimulated plasma catecholamine levels were meas ured in 42 diabetic patients with and without pathological cardiovascu lar function tests and in 13 healthy, non-diabetic control subjects. I n addition, the excretion of catecholamines was measured in a 24 h uri ne collection and compared with the stress stimulated plasma levels. D uring mental stress exposure a diminished epinephrine secretion was fo und in diabetic patients with autonomic neuropathy compared with diabe tic patients without neuropathy and the healthy control group (p < 0.0 5; respectively). The decreased epinephrine response to mental stress was strongly correlated with a diminished urinary excretion of this 'n eurotransmitter' (r = 0.46; p < 0.01). Diabetic patients suffering fro m cardiovascular autonomic neuropathy exhibit a diminished sympatho-ad renal response following mental stress exposure. Both measurement of u rinary and mental stress stimulated plasma epinephrine levels followin g mental stress provide reliable information regarding sympatho-adrena l activity in diabetic patients.