Impaired blood pressure response to norepinephrine in a case of insulin-dependent diabetes mellitus--improvement with a beta-adrenergic antagonist.

A case of juvenile-onset insulin-dependent diabetes mellitus in a 30-year-old male patient is reported. He was admitted to the hospital because of severe diabetic neuropathy, predominantly in the lower extremities. Signs of autonomic neuropathy were not evident but the patient had severe orthostatic hypotension. Circulating catecholamine concentrations were normal; however, the blood pressure response to infused norepinephrine was reduced ten-fold compared to a group of normals. An improvement of the blood pressure response to sympathomimetic drugs was accomplished during the simultaneous administration of propranolol, a beta-receptor blocking agent. The present data suggest a possible defect of the adrenergic receptor system in response to sympathomimetic drugs while the release of catecholamines and the function of the parasympathetic nervous system appears to be intact. Treatment with beta-blocking agents such as propranolol as an adjunct to sympathomimetics seems to be a promising approach which might deserve further consideration in similar cases.