Association Between Plasma Lipids Profile and Lipids Oxidizability in Healthy Men

The aim of the present study was to determine the susceptibility of lipids to Cu-induced peroxidation in diluted plasma and its relation with plasma lipids and lipoproteins in a group of healthy men. In 100 healthy men volunteers (age range 20-55 years with a mean of 36.8±10.3 years), fasting plasma levels of lipoprotein (a) [Lp (a)], total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and triglycerides (TG) were assayed. The Cu2+-induced lipid peroxidation was evaluated. Lipid oxidation was estimated by monitoring the change of conjugated dienes in the diluted plasma following the addition of Cu2+. The kinetic curves of the accumulation of lipid peroxide products were prepared, and a number of quantitative parameters including lag time, time of maximal oxidation rate (T-max), and maximal accumulation of absorbing products (OD-max) were evaluated. The TG concentrations were positively correlated with lag time and T-max (r=0.33, P < 0.01 and r=0.24, P < 0.05) respectively. Also, TC and LDL-C were positively correlated with OD-max (r=0.28, P < 0.01 and r=0.26, P < 0.05 respectively), and HDL-C was negatively correlated (r=-0.23, P < 0.05) with T-max. No significant correlation was observed between other variables and lipid oxidizability parameters. Results of this research indicate that TG increased the resistance of LDL and VLDL against initiation of lipid oxidation. In addition, HDL-C induced the susceptibility of lipid oxidizability.