Nitro-oxidative stress biomarkers in active and inactive men

Abstract

Oxidative stress markers are novel factors shown to be related to cardiovascular (CVD) risk. We examined the effects of long-term exercise, age, and their interaction on plasma oxidized LDL (ox-LDL), nitrotyrosine, and myeloperoxidase (MPO) levels, all biomarkers of oxidative stress, and determined their association with plasma nitric oxide (NOx) levels as an index of NO bioavailability. Older (62±2 yr) active men (n=12) who had exercised for >30 years and young (25±4 yr) active men (n=7) who had exercised for >3 years were age- and BMI-matched to older (n=11) and young (n=8) inactive men. Young subjects had lower plasma nitrotyrosine levels than older subjects (P=0.047). Young inactive subjects had higher ox-LDL levels than either the young active (P=0.042) or the older active (P=0.041) subjects. In addition, plasma oxidative stress levels, particularly ox-LDL, were correlated with various conventional plasma lipoprotein-lipid levels, and in older subjects were associated with Framingham risk score (r=0.49, P=0.015). We found no relationships between plasma oxidative stress markers and NOx levels. The findings suggest that a sedentary lifestyle may be associated with higher ox-LDL levels and that the levels of oxidative stress markers are related to levels of other conventional CVD risk factors and overall CVD risk.