Figure 6. Correlation between serum N – epsilon carboxy methyl lysine (N^ε-CML) and ” and peripheral blood mononuclear cell reactive oxygen species (PBMC ROS) level. A, B, C, D: The XY scatterplot represents the correlation between serum N^ε-CML levels and PBMC ROS levels among healthy control (HC), diabetic without retinopathy (DNR), nonproliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) subjects. A significant correlation was observed in between serum N^ε-CML levels and PBMC ROS levels among NPDR (p<0.0001; r=0.5687) and PDR (p=0.0034; r=0.2863) subjects, but no significant correlation was found in DNR (p=0.2344; r=0.1188) and HC individuals (p=0.3875; r=0.0896).