Cholesterol standardized plasma vitamin E levels are reduced in patients with severe angina pectoris

Vitamin E, the major lipid soluble plasma antioxidant, has been reported to be reduced in patients with coronary atherosclerosis. We have measured the levels of plasma alpha-tocopherol (the predominant form of plasma vitamin E) in 128 patients with different reported degrees of angina. Patients with mild to moderate angina (grades I or II (CSS score)) (n = 64), and patients with severe angina (grades III and IV) (n = 64) were recruited from Cardiology Clinics in the U. K. Healthy controls (n = 33) and patients with hyperlipidaemia (n = 28) were also recruited. The groups of patients with angina did not differ significantly for mean age (58 +/- 1.0 years vs. 59 +/- 1.0 years, respectively); sex distribution (the M:F ratio was 48 : 16 and 46 : 18 for the respective groups); or prevalence of smoking (12% vs. 9%), or hypertension (19% vs. 33%). Total cholesterol levels were higher in the group with severe angina (5.9 +/- 0.16 mmol/l vs. 5.3 +/- 0.13 mmol/l P < 0.05). Absolute levels of plasma vitamin E were not significantly different between the angina subgroups (12.9 +/- 0.40 mg/l for the mild-moderate angina group vs. 12.5 +/- 0.51 mg/l for the severely affected group), but were positively correlated with plasma cholesterol concentrations in each case (P < 0.001). The ratio between plasma vitamin E: total cholesterol was significantly lower in the patients with severe angina (mean 2.20 +/- 0.09 mg/mmol) vs. a mean value of 2.46 +/- 0. 08 mg/m mol in the mildly affected group (P < 0.05). The plasma vitamin E: total cholesterol ratio in patients with severe angina was also significantly lower (P < 0.05) compared to either healthy controls with comparable total cholesterol levels (n = 33), or hypercholesterolaemic subjects (n = 28) without symptomatic coronary disease (mean ratios were 2.69 +/- 0.40 mg/mmol and 2.74 +/- 0.68 mg/mmol, respectively). Vitamin E has previously been demonstrated to protect endothelial function in the presence of hypercholesterolaemia, possibly by preserving nitric oxide bio-activity. It also inhibits LDL oxidation. Hence, a high plasma vitamin E: total cholesterol ratio may be associated with an amelioration of angina.