PLASMA AND LDL LEVELS OF MAJOR LIPOPHILIC ANTIOXIDANTS ARE SIMILAR INPATIENTS WITH ADVANCED ATHEROSCLEROSIS AND AGE-MATCHED CONTROLS

Oxidative modification of low-density lipoprotein (LDL), regarded an e arly event in atherogenesis, is associated with the depletion of the l ipoprotein's antioxidants. We tested whether the levels of major lipop hilic antioxidants in the blood of patients with advanced atherosclero sis are different to those in age-matched controls. On average, plasma ubiquinol-10, total coenzyme Q, and coenzyme Q redox status were slig htly lower whereas the levels of alpha-tocopherol were slightly higher in patients (63 +/- 11 years, n = 32) than controls (64 +/- 10 years, n = 24). However, these differences were not statistically significan t (p > 0.05). The levels of antioxidants in LDL isolated from a subset of patients (n = 20) and controls (n = 15) were also indifferent, and hydroperoxides of cholesteryl esters were undetectable (detection lim it 10 nM) in plasma of patients (n = 11) and controls (n = 10). The da ta suggests that plasma and LDL levels of lipophilic antioxidants are not depleted in patients suffering from severe atherosclerosis, and th at neither parameter serves as a useful diagnostic indicator for this disease.