Endothelial factors, toe temperature and leg circulation in diabetics with and without autonomic neuropathy

A low plasminogen activator response to venous occlusion is frequently found in diabetes. The aims of this investigation were to study any relationships between plasminogen activator activity and autonomic neuropathy (AN), and between abnormal toe temperature reactions and AN. Asymptomatic AN is frequently found in insulin dependent diabetics. The results might be an abnormal balance between the parasympathetic and sympathetic innervation of the vessels, which in turn will lead to a change of the reaction to cooling of the feet followed by indirect heating. In this study 52 insulin dependent diabetics were examined with a combination of tests for AN and blood flow measurements as well as plasminogen activator activities of the blood and vascular walls. In patients with a short duration of diabetes (mean 11 years) the prevalence of AN was high in those with abnormally slow increase in toe temperature after cooling followed by indirect heating. The mechanism behind appeared to be a functional vasospasm. In diabetics of short as well as of long duration (mean 35 years), an abnormally low plasminogen activator activity of the blood during venous occlusion was found in those without AN, while those with AN showed a normal activity. Thus, AN might influence the deterioration of the circulation in diabetes.