Alterations in oxidative stress biomarkers associated with mild hyperlipidemia and smoking

Oxidative stress may increase the risk of atherosclerosis. The association of mild forms of hyperlipidemia, particularly primary hypertriglyceridemia, with oxidative stress has not been fully investigated. The aim of this study was to assess the alterations in oxidative stress biomarkers associated with three major types of mild untreated hyperlipidemia (hypercholesterolemia, hypertriglyceridemia and combined hyperlipidemia) in nonsmoker and smoker individuals. Five biomarkers were measured in 139 adult healthy men (83 nonsmokers and 56 smokers, ages 18-75), which included normolipidemic and hyperlipidemic subjects. Triglyceride levels were associated with a significant main effect on ferric reducing antioxidant power (FRAP) and 8-iso-prostaglandin F2α (iPF2α) levels in plasma (p<0.05 and p<0.005, respectively). Smokers with hypercholesterolemia, hypertriglyceridemia and combined hyperlipidemia had alterations in 1, 3 and 2 oxidative stress biomarkers compared to nonsmoker normolipidemics. Smokers (including normolipidemics and hyperlipidemics) had higher plasma FRAP (120.8 vs. 102.0 μM quercetin/l, p<0.05) and erythrocyte catalase activity (5125 vs. 4093 U/g Hb, p<0.01), while they had lower erythrocyte glutathione peroxidase activity (20.3 vs. 23.0 U/g Hb, p<0.05) compared to nonsmokers. These findings show that mild forms of hyperlipidemia, particularly in smokers, are associated with alterations in some oxidative stress biomarkers.