[Determination of plasma concentrations of antioxidants, antibodies against oxidized LDL, and homocysteine in a population sample from Liège].

A large number of epidemiological and clinical studies suggest that oxidative stress plays an important role in the development of cardiovascular diseases. In this way, following reference values in plasmatic antioxidants have been determined in a group of 123 blood donors (94 males, 29 females; age: 21-64 years) living in the surroundings of Liege, Belgium: vitamin A (1.5-3.62 mmol/l), vitamin C (3.68-75.21 mmol/l), vitamin E (16.98-46.46 mmol/l), ratio vitamin E/cholesterol (3.92-8.32 mmol/mmol), selenium (0.66-1.26 mmol/l), sulphydryl proteins (216-556 mmol/l), uric acid (174-477 mmol/l), superoxide dismutase (542-852 IU/g hemoglobine), glutathion peroxidase (39.55-91.83 IU/g hemoglobine). Only a few number of subjects were found with values corresponding to high risk of deficiency in antioxidants although low values in vitamin C (< 11.35 mmol/l) and in selenium (< 0.75 mmol/l) were respectively observed in 5.69 and 10.5% of our subjects. Autoantibodies against oxidized LDL, as marker of oxidative stress, and homocysteine, as a risk factor of atherosclerosis involved in the development of oxidative stress, have also been investigated. Approximatively 40% of the population presented values higher than the superior limit mean value (20.3% > 650 IU/l in autoantibodies and 19.5% > 15.2 mmol/l in homocysteine) that are, however, not correlated with age or low levels in antioxidants. The effect of smoking (25% of the population) contributed to significantly decrease vitamin C, selenium and glutathion peroxidase concentrations by 31.9 and 13% when compared to nonsmokers. Intake of 1 to 4 fruits per day resulted in a significant increase of 56.9% in vitamin C when compared to nonconsumers (26.8% of the population). In contrast, homocysteine concentrations were significantly decreased by 21.4% in fruits consumers. Thank to the development of methods allowing the routine dosage of all these parameters, general practitioners can now easily establish the oxidative stress status of their patients and, as fonction of getting patterns, detect populations at risk of developing cardiovascular diseases.