Lower Limb Venous Pressure in Diabetic Neuropathy

Abstract

OBJECTIVE Distended turgid veins have been noted in the feet of patients with diabetic neuropathy. This study assessed the supine venous pressure and its correlation with diabetic neuropathy and arteriovenous (AV) shunting in the feet of type I and type II diabetic subjects. RESEARCH DESIGN AND METHODS Seventeen patients with chronic Charcot joints, 11 patients with a history of neuropathic foot ulceration, 14 diabetic control subjects, and 11 normal control subjects were studied. Neuropathy was assessed by vibration and thermal thresholds and standard cardiovascular autonomie neuropathy tests. Supine venous pressure was measured by insertion of a 21-gauge needle connected to a strain gauge manometer into the veins on the dorsum of the foot. Venous Po2 was used as a measure of AV shunting. RESULTS Venous pressure was raised in the group with chronic Charcot joints (18.9 ± 4.2mmHg, P < 0.001 vs. the diabetic control group [11.3 ± 2.6mmHg]), the normal control group (12.3 ± 2.3 mmHg, mean ± SD), and the diabetic group with a history of neuropathic foot ulceration (16.0 ± 3.7 mmHg, P = 0.008 vs. diabetic control subjects and P = 0.04 vs. normal control subjects), with a maximum of 28 mmHg. Venous pressure was correlated with heart rate variation to deep breathing, r = −0.61 (P = 0.001), vibration threshold, r = 0.56 (P = 0.001), Valsalva ratio, r = −0.64 (P = 0.001), warm threshold, r = 0.69 (P = 0.001), and venous Po2, r = 0.43 (P = 0.02). There was no correlation with skin temperature, duration of diabetes, age, HbAlc, random blood glucose, ankle/brachial Doppler index, height, or serum creatinine. CONCLUSIONS Venous pressure is much higher in the neuropathic diabetic limb and is correlated with the severity of neuropathy and with AV shunting.