2.4 Oxidized LDL in risk prediction

Is oxLDL, as measured with the Mercodia Oxidized LDL ELISA, just another assay for LDL-cholesterol or does oxLDL provide any additional information? The overall correlation of oxLDL to LDL-cholesterol is about 0.70 (R2=0.4886) (Figure). However, if the LDL-cholesterol levels are divided into quartiles, the correlation of oxLDL to LDL-cholesterol decreases with increasing blood levels of LDL-cholesterol with a slight increase in correlation in the highest quartile. In a study of 148 subjects blood levels of oxLDL and LDL-cholesterol were measured. LDL- cholesterol levels were divided into quartile I (0.8-2.6 mM), II (2.6-3.2 mM), III (3.3-3.8 mM) and IV (3.8-5.8 mM). The correlation of oxLDL to LDL- cholesterol was 0.65 (R2=0.42) in quartile I, 0.17 (R2=0.0285) in quartile II, 0.13 (R2=0.0168) in quartile III and 0.29 (R2=0.0814) in quartile IV (Table). Thus, the correlation of oxLDL to LDL-cholesterol is lost at elevated LDL-cholesterol levels.