Vitamin E prevents extensive lipid peroxidation in patients with hypertension

Oxidative modification of low-density lipoprotein (LDL) increases atherogenic potential to induce the accumulation of lipids and cells in the vascular wall. Previous studies reveal that hypertensive patients have a higher susceptibility to LDL oxidation. As animal models indicate that vitamin E protects LDL from oxidation, here we study the influence of vitamin E on the resistance of LDL to oxidation (lag time) in 47 subjects (31 normotensive, 16 hypertensive) before and after oral administration of vitamin E (400 IE) daily for two months. LDL was isolated and oxidised by incubation with copper ions. The time course of oxidation was measured by continuous photometric monitoring of diene formation at 234 nm. At the beginning of this study, normotensive subjects showed a lag time of 108 +/- 26 minutes and hypertensive patients a lag time of 85 +/- 24 minutes (P<0.05). Vitamin E caused a significant increase in the lag time in both groups: normotensive subjects 128 +/- 33, hypertensives patients 114 +/- 27 minutes (P<0.01). At completion of the study, lag times in both groups were similar (P=not significant). The data presented here suggests that vitamin E protects against the increased risk of vascular disease in patients with hypertension by reducing the susceptibility to oxidative modification of LDL. Vitamin E may therefore act as an inhibitor of atherogenesis.