Cardiovascular, metabolic, and hormonal responses to noradrenaline in diabetic patients with autonomic neuropathy

Denervation hypersensitivity is a well-known phenomenon in patients with autonomic failure. In diabetic autonomic neuropathy hypersensitivity to beta-adrenergic stimulation has been demonstrated. We infused noradrenaline, mainly an alpha-adrenoceptor agonist, in three escalating doses (0.5, 2.5, and 5 micrograms min-1) in three age and sex matched groups of eight subjects: healthy volunteers, diabetic patients with and without autonomic neuropathy. During steady state in each infusion period we measured heart rate, blood pressure, cardiac output, hepato-splanchnic blood flow, vascular resistance, glucose kinetics, metabolites (beta-hydroxybuturate, glycerol, and lactate), and glucoregulatory hormones (noradrenaline, adrenaline, growth hormone, pancreatic polypeptide, cortisol, and insulin). Systolic and mean blood pressure increased in all groups but diabetic patients with autonomic neuropathy showed a significantly higher increase (p