LOW LDL OXIDATION IN VETERAN ENDURANCE ATHLETES

The 'oxidation hypothesis' states that oxidative modification of low-d ensity lipoprotein (LDL) is important in the pathogenesis of the ather osclerotic lesion. Physical exercise has been reported to reduce clini cal manifestations of atherosclerosis. We compared the effects of aero bic physical exercise history on oxidation characteristics of plasma L DL at rest in non-smoking male veteran endurance athletes (n=15) and c ontrol subjects (n=16). As an indicator of LDL oxidation we used a met hod which provides an estimate of LDL diene conjugation in vivo. The a thletes had lower plasma LDL cholesterol diene conjugation (P=0.003). They also had lower cholesterol, lower LDL and higher high-density lip oprotein (HDL) cholesterol. Intensive physical exercise energy expendi ture correlated inversely with LDL diene conjugation (r=-0.41, P=0.021 ). We conclude that participation in intensive physical exercise train ing is associated with reduced plasma LDL fraction oxidation as reflec ted by LDL diene conjugation. This finding may have relevance for stud ies aiming to explain the variation in occurrence of ischemic heart di sease.