Oxidized Low-Density Lipoprotein (ox-LDL) to LDL Ratio (ox-LDL/LDL) and ox-LDL to High-Density Lipoprotein Ratio (ox-LDL/HDL).

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL) plays a principal role in diabetes complications, though ox-LDL concentrations and its functions are dependents of other oxidative and anti-oxidative particles. The oxLDL to low-density lipoprotein ratio (ox-LDL/LDL) and ox-LDL to high-density lipoprotein ratio (ox-LDL/HDL) as new lipid biomarkers may serve as a good estimation of oxidation and anti-oxidation in type 2 diabetes mellitus. The aim of this study was first to examine ox-LDL/LDL and ox-LDL/HDL levels in patients with type 2 diabetes mellitus compared to a control group and evaluate their diagnostic accuracies, and, second, to investigate the correlation of these two ratios with triglyceride and HDL levels.

METHODS

This study was included 144 patients admitted to the diabetes clinic of a University general hospital and 41 healthy individuals as controls. Levels of LDL, HDL, triglyceride (TG) ox-LDL, and malondialdehyde (MDA) were measured for all patients. Levels of ox-LDL/LDL and ox-LDL/HDL were calculated. Diagnostic accuracies were determined by receiver-operating characteristic curve analysis by measuring the area under the curve.

RESULTS

Ox-LDL, ox-LDL/LDL, and ox-LDL/HDL were significantly higher in patients compared to the control group after adjustment for age, gender, and BMI (p = 0.000). The area under the curve for diagnosing diabetes was 0.946 for ox-LDL/HDL, 0.918 for ox-LDL/LDL, and 0.832 for ox-LDL. Ox-LDL/HDL was positively correlated with MDA (r = 0.210, p = 0.011). Ox-LDL/LDL was negatively correlated with HDL (r = -0.2 p = 0.016) and positively correlated with TG (r = 0.45 p = 0.000). Ox-LDL/HDL and TG had significant positive correlation (r = 0.173 p = 0.037). The ox-LDL/LDL level was significantly higher in patients with coronary heart disease (CHD) or hypertension (HTN) compared to those without (p = 0.042).

CONCLUSIONS

Our findings revealed that ox-LDL/LDL and ox-LDL/HDL are potent biomarkers of type 2 diabetes, which apparently reflect the association between lipids in the state of oxidative stress.