Effect of vitamin E supplementation on circulating cell adhesion molecules pre- and post-coronary angioplasty

Abstract

The soluble adhesion molecules P-selectin (sP-selectin) and intercellular adhesion molecule-1 (sICAM-1) are derived from platelets and endothelial cells. Circulating concentrations of these soluble adhesion molecules are raised in patients with atherosclerosis and following percutaneous transluminal coronary angioplasty (PTCA). We have investigated the effects of vitamin E supplements (800 IU/day) on circulating plasma ICAM-1 and P-selectin levels pre- and post-PTCA. Patients, randomized to group, were pre-treated with vitamin E or placebo (soybean oil) for 1 month before routine PTCA. Plasma sICAM-1 and sP-selectin were measured by enzyme-linked immunosorbent assay on blood taken immediately pre- and post-PTCA. Total protein and alpha-tocopherol were measured on the same samples. Plasma alpha-tocopherol concentrations increased in patients receiving vitamin E: 19.1 (1.5) [mean (standard error of the mean, SEM)] mg/mL post-PTCA versus 13.9 (0.6) mg/mL pre-PTCA (n=23; P<0.01). Plasma sP-selectin and sICAM-1 levels were not significantly increased following PTCA in the vitamin E group. Pre-angioplasty mean (SEM) plasma sP-selectin concentration in the vitamin E group was 8.83 (0.97) ng/mg protein; the corresponding mean post-angioplasty value was 9.34 (0.89) ng/mg protein (P=0.85). The mean (SEM) pre-angioplasty sICAM-1 concentration in this group was 2.18 (0.24) ng/mg protein, and was 2.20 (0.23) ng/mg protein following angioplasty (P = 0.84). In the placebo group (n = 24) there was a significant increase in mean (SEM) sP-selectin concentration following angioplasty, from 7.48 (0.73) to 9.70 (0.78) ng/mg protein (P<0.05). The change (mean, SEM) in plasma sP-selectin concentration following angioplasty was significantly greater for the placebo group [2.22 (0.50) ng/mg protein] than for the group receiving vitamin E [0.50 (0.50) ng/mg protein] (P<0.02). This difference remained significant (P<0.05) even after adjustment for pre-angioplasty P-selectin concentrations. Mean (SEM) plasma sICAM-1 concentrations remained unchanged following angioplasty [pre-angioplasty: 2.16 (0.20) ng/mg protein; post-angioplasty: 1.97 (0.13) ng/mg protein]. Vitamin E may therefore limit platelet or endothelial activation during PTCA.