Association between lipid peroxidation and carotid artery intima media thickness (IMT) in a European population study (IMPROVE PROJECT)

The aim of this study was to evaluate the relationship between lipid peroxidation and cross-sectional intima-media thickness (IMT) in a European multicenter study (Carotid IMT and IMT progression as Predictors of Vascular Events in a High Risk European Population project. IMPROVE). Seven clinical centres were included. Two centres were in Italy, two centres in Finland, and one centre in Sweden, in The Netherlands and in France. Of over 3600 subjects participating in IMPROVE, a randomized subgroup of 560 men and women were included in lipid peroxidation assays at the baseline visit. Serum LDL conjugated, dienes were measured spectrophotometrically in 554 subjects, and F2-isoprostanes in 24-hour urine of 544 subjects by gas chromatography-mass spectrometry. IMT was measured by B-mode ultrasound. The readings of the ultrasound scannings were performed in one Central Reading Centre. Women had significantly higher urinary F2-isoprostane excretion (1.41±0.06 µg/mg creatinine) than men (1.17±0.06 µg/mg creatinine), but there was no gender difference in LDL conjugated dienes. There was a significant decreasing trend (P<0.0001) in serum LDL conjugated dienes from Northern to Southern part of Europe. After adjustment for age, gender, center, sonographer and reader, conjugated dienes did not associate with any IMT variable. However, the lMT mean of internal carotid arteries increased significantly (p=0.0201) with the increasing content of F2-isoprostanes in urine. Urinary F2-isoprostanes may be an indicator of increased atherosclerosis. Interestingly, serum LDL conjugated diene content was increased in Northern part of Europe as compared with the Southern part.