STRONG INCREASE IN HYDROXY FATTY-ACIDS DERIVED FROM LINOLEIC-ACID IN HUMAN LOW-DENSITY LIPOPROTEINS OF ATHEROSCLEROTIC PATIENTS

Linoleic acid is the most abundant fatty acid in human low density lip oproteins (LDL). Oxidation of LDL transforms linoleic acid to hydroper oxyderivatives. These are converted to 9-hydroxy-10,12-octadecadienoic acid (9-HODE) and 13-hydroxy-9,11-octadecadienoic acid (13-HODE). 9-H ODE is much more abundant in oxidized LDL than other lipid peroxidatio n products and therefore an indicator of lipid peroxidation (LPO). In this study the 9-HODE content in the LDL of 19 obviously healthy volun teers and 17 atherosclerotic patients was investigated. The level of 9 -HODE obtained from LDL of young atherosclerotic patients (aged 36-47 years) was increased by a factor of 20 when compared with samples from healthy volunteers of the same age group. The content of 9-HODE in th e LDL of atherosclerotic patients aged between 69 and 94 years increas ed 30-100 fold when compared with young healthy individuals, but when compared with 'healthy' individuals of the same age group it was only 2-3 fold increased. Obviously, as individuals grow older LDL becomes m ore and more oxidized. Consequently, assuming that LDL oxidation is a precondition for atherosclerosis-older individuals will suffer from at herosclerosis, even if no easy detectable visible signs of this diseas e are recognizable. According to 9-HODE determination, the onset of th e disease starts slowly in most individuals at around 50 years of age. (C) 1998 Elsevier Science Ireland Ltd.