EFFECT OF AGING ON SUSCEPTIBILITY OF LOW-DENSITY LIPOPROTEINS TO OXIDATION

According to the Adult Treatment Panel of the National Cholesterol Edu cation Program, age is a major risk factor for heart disease. To asses s the relation between age and LDL oxidizability, we studied copper-me diated LDL oxidation in 13 healthy elderly subjects (>59 years) and 13 sex-matched healthy young controls (<30 years). Total and LDL-cholest erol concentrations were increased in elderly subjects, The time cours e of copper-mediated LDL oxidation showed no significant differences b etween the two groups as assessed by formation of conjugated dienes, l ipid peroxides, and apolipoprotein B fluorescence. Kinetics of LDL oxi dation as quantified by lag time, oxidation rate, and maximal oxidatio n were not significantly different between the elderly and young group s. Although the concentrations of 16:0, 18:0, 18:1, 18:3, and 20:4 and total polyunsaturated fatty acids were significantly higher in the el derly group, LDL fatty acid concentrations were similar in both groups . Lipid-standardized alpha-tocopherol, beta-carotene, and ascorbate co ncentrations were not significantly different between the two groups. The findings of the present study suggest that in the healthy elderly, LDL oxidation may not be a crucial mediator for atherogenesis.