Autonomic function tests in diabetes mellitus

Five tests of autonomic function were evaluated in a group of twenty-five diabetics. The Valsalva ratio proved to be the most valuable single indicator of generalised autonomic dysfunction, whilst the blood pressure response to sustained handgrip, the pupillary response to a dilute solution of methacholine and the fall in blood pressure on standing, all proved to be less valuable as indices of autonomic neuropathy either when considered individually or when taken together. The cold pressor test was shown to be of no value in the assessment of patients with autonomic neuropathy. It is suggested that of those examined the Valsalva procedure is the most valuable simple outpatient test for autonomic neuropathy.