Circulating oxidized LDL is associated with increased waist circumference independent of body mass index in men and women.

BACKGROUND Obesity is associated with oxidative stress, and the oxidation of LDL is thought to play a crucial role in the generation of atherosclerotic lesions. OBJECTIVE The objective was to describe the association of waist circumference (WC) and body mass index (BMI; in kg/m2) with plasma circulating oxidized LDL (ox-LDL) and C-reactive protein (CRP). DESIGN This cross-sectional study included data for circulating ox-LDL and CRP from a subpopulation of 586 men and women enrolled in a population-based survey conducted in 2000 in Girona, Spain. Multivariate analysis was performed to describe the independent association of WC and BMI with ox-LDL and CRP. RESULTS Multivariate logistic regression analysis adjusted for lifestyle, educational level, and dietary confounders showed a direct association of WC (quartile distribution) and BMI categories with ox-LDL (P for linear trend = 0.002) and CRP (P for linear trend = 0.004). Subjects in the top quartile of WC and with a BMI > 29.9 were at high risk of elevated circulating concentrations of ox-LDL and CRP. Further adjustment for cardiovascular disease risk factors did not substantially modify these associations. The risk of high ox-LDL concentrations in overweight (BMI = 25.0-29.9) or obese (BMI > or = 30) subjects with a WC < 102 cm (men) or < 88 cm (women) was not significantly different from that in normal-weight subjects with these WCs. In contrast, overweight or obese subjects with higher WCs (WC > or = 102 cm for men and > or = 88 cm for women) were at significantly higher risk of increased ox-LDL. CONCLUSION High WC was associated with high concentrations of ox-LDL independently of BMI in the study population.