[Atherosclerosis and anti-oxidized low density lipoprotein antibodies in an elderly population]

Antibodies to oxidized LDL (anti-OxLDL) have been found to be associated with atherosclerosis. The aim of the study was to evaluate the relationship between anti-OxLDL antibodies and atherosclerosis in the elderly.

We studied several risk factors and different clinical manifestations of atherosclerosis in 100 people older than 65 years and in 48 healthy blood donor controls (age range: 20 to 55 years). Anti-OxLDL antibodies were measured by ELISA.

Thirty-one percent of the patients tested positive for anti-OxLDL. This percentage increased in the group of subjects without any risk factor or clinical manifestation (66.6%) as it was the case of the mean optical density (O.D.) value (O.D. = 0.671 vs. 0.357 in our general geriatric population). Most of those with a proven atherosclerotic event tested negative for anti-OxLDL antibodies and a statistically significant difference was shown for those with a calcified aortic arch (P = 0.041, 95% CI 0.15-0.97). Mean value of risk factors and clinical manifestations was 3.50 among anti-OxLDL-negative patients, whereas it was 2.51 in the anti-OxLDL-positive group (P = 0.035, 95% CI 0.07-1.91). Actually, when more adverse effects were present, patients' trend to test negative for anti-OxLDL antibodies was higher. An inverse correlation was observed between anti-OxLDL titers and the relative risk of coronary heart disease (P = 0.020).

The cause of the decrease of free anti-OxLDL antibodies in situations that lead to an oxidative stress is unknown but it may be explained by the formation of immunocomplexes in an effort to ease the clearance of oxidized substrates.