INCREASE IN HYDROXY FATTY-ACIDS IN HUMAN LOW-DENSITY LIPOPROTEINS WITH AGE

The content of hydroxy fatty acids in low density lipoprotein (LDL) of healthy volunteers aged between 22 and 87 years without any signs of atherosclerosis or other age-dependent diseases was investigated. The level of hydroxy fatty acids obtained from LDL increases during life t ime: clinically healthy persons between 56 to 66 years showed a 3- to 4-fold increase compared to young volunteers. This level increased in samples of probands aged 68 to 74 years compared to samples of young p eople for a factor of 10-20 and in samples of probands aged 78 to 87 y ears for a factor of 30-40. These hydroxy acids - generated mainly fro m hydroperoxy acids of linoleic acid and only partly from arachidonic acid - are obviously parameters of the LDL oxidation stage. About 90% of the total amount of hydroxy fatty acids were free fatty acids. The distribution patterns of the monohydroxy derivatives of linoleic and a rachidonic acid indicate that they originate mainly from autocatalytic processes. The individual level of hydroxy acids is probably an indic ator of the biological age. Copyright (C) 1996 Elsevier Science Irelan d Ltd