Influence of selenium on postischemic brachial artery dilation in patients with peripheral arterial occlusive disease and selenium deficiency: A monocentric prospective controlled open pilot study

In an open prospective phase-IV pilot study the effect of selenium (intravenous bolus injection of 500μg sodium selenite) was investigated on the brachial artery diameter of patients (n=20) with peripheral arterial occlusive disease in stage II according to Fontaine (PAODII) and selenium deficiency. Flow-mediated vasodilation was assessed under resting conditions (control phase) and at 5 and 30 seconds after cuff deflation completing suprasystolic compression of the upper arm. After 30 minutes, 500 μg of selenium was injected as bolus and the above mentioned measurement procedure was repeated. Taken at rest, the mean brachial artery diameter of the 20 patients with PAOD was 4.14±0.44 mm. Immediately after injection of selenium, the diameter increased to 4.65±0.45 mm, i.e. in average about 0.51 mm or 12.25 per cent (p<0.0001). Consequently, this open study showed that under resting conditions selenium has a marked effect on brachial artery diameter. The respective mean brachial artery diameters measured at 5 and 30 seconds after cuff deflation were significantly larger by 0.418 mm (p<0.0001) and 0.42 mm (p<0.0001) after selenium injection than before treatment with selenium. This indicates that despite vasodilation under resting conditions postischemic reactive hyperemia was not negatively influenced. Selenium mediated vasodilation was as pronounced in the phase of reactive hyperemia as under resting conditions. The brachial artery diameters of the patients were identical before each testing phase (p=0.945); homogeneity at baseline was given; a carry-over effect was ruled out. In all, the study provides clear though not evidential results accountable to the pilot character of the study and biometric specifications. The study will, nevertheless, prove valuable as hypothesis generation and as basis of a data based sample size calculation for a future, prospective placebo-controlled randomized clinical study.