Lipoprotein Oxidation and Plasma Vitamin E in Nondiabetic Normotensive Obese Patients

OBJECTIVE: To correlate the susceptibility of low-(LDL) and very-low-density lipoprotein to oxidation in vitro and the concentrations of serum antibodies against malondialdehyde-modified LDL and plasma vitamin E with the anthropometric and laboratory characteristics of obesity. RESEARCH METHODS AND PROCEDURES: A total of 75 nondiabetic, normotensive obese patients were assigned to one of four groups according to their body mass index (BMI): moderately obese (30 50 kg/m(2), n = 15). RESULTS: The oxidation lag time for LDL from patients with a BMI >or=35 kg/m(2) was shorter than that for LDL from non-obese controls (n = 13), whereas very-low-density lipoprotein oxidation lag times were not significantly different. The serum antibodies against modified LDL were similar in all groups, whereas the plasma vitamin E concentrations of obese patients were decreased (p <or= 0.01). There was a negative correlation between LDL oxidation lag time and BMI (r = -0.35, p = 0.0008), and between plasma vitamin E and BMI (r = -0.53, p < 0.0001) and waist-to-hip ratio (r = -0.40, p = 0.0003). DISCUSSION: The LDL of nondiabetic, normotensive obese patients is more readily oxidized, and plasma vitamin E concentrations are low. These are both risk factors for coronary heart disease.