Diabetic neuropathy results in vasomotor dysfunction of medium sized peripheral arteries

ARTICLE HIGHLIGHTS

Research background

When the smooth muscle cells lining blood vessels contract in response to stimulation from the sympathetic nervous system, the result is vasoconstriction and a decrease in blood flow to the extremities.

Research motivation

To identify a different method for the detection of diabetic autonomic neuropathy that does not impair patient comfort.

Research objectives

The goal of this research was to determine whether there is major vasomotor dysfunction of medium-sized arteries in diabetic neuropathy by comparing the sympathetic vasomotor activation of the brachial arteries in healthy people and patients with painful diabetic neuropathy.

Research methods

A 10 mA, 1 Hz electrical stimulus was applied to the median nerve in the wrist for 5 s using a bipolar stimulus electrode. Following stimulation, the diameter of the brachial artery and the blood flow rate were re-measured.

Research results

In the control group, the median flow rate was 70.0 mL/min prior to stimulation and 35.0 mL/min after stimulation, with a statistically significant decrease (P < 0.001) which is consistent with sympathetic nervous system functioning (vasoconstriction). In the diabetic neuropathy group, median flow rate before stimulation was 35.0 mL/min. After stimulation, the median flow rate was 77.0 mL/min; thus, no significant decrease in the flow rate was detected. In the control group, the median brachial artery diameter, which was 3.6 mm prior to stimulation, decreased to 3.4 mm after stimulation, and this decrease was also statistically significant (P = 0.046). In the diabetic neuropathy group, the median brachial artery diameter increased from 3.4 mm to 3.6 mm following nerve stimulation. Once again, no narrowing was observed.

Research conclusions

Our study shows that diabetic neuropathy causes medium-sized peripheral arteries to have blood flow problems. In diabetic neuropathy, the body cannot constrict blood vessels normally when the sympathetic nervous system is activated.

Research perspectives

We will try this new method in the clinic in the future.