In vivo oxidizability of LDL in type 2 diabetic patients in good and poor glycemic control

We aimed to determine if increased non-enzymatic glycosylation of the LDL was sufficient to increase the susceptibility to in vivo oxidation of the LDL particles. Twenty-two type 2 diabetic patients (11 males and 11 females) were included in this study. They were enrolled on the basis of good [glycated hemoglobin (HbA1c)<7%] and poor glycemic control [(HbA1c)>8%]. LDL were isolated by sequential ultracentrifugation and analyzed by capillary electrophoresis (CE) for diene conjugate content and for electronegativity. The glyc-LDL levels were increased in all diabetic type 2 patients, peaking in the diabetic subjects in poor diabetic control (17.3±8.07%). The LDL content of diene conjugates was similar between the two groups (6.65±0.77% for the patients with good glycemic control versus 6.88±0.74% for those with poor glycemic control; P=0.49) as was the electrophoretic mobility ((−1.14544±0.089)×10−4 cm2/(V s) for the patients with good glycemic control and (−1.13666±0.073)×10−4 cm2/(V s) for those with poor glycemic control; P=0.80). The susceptibility to in vivo oxidation of LDL from type 2 diabetic patients in poor glycemic control did not differ from that of well-controlled diabetic patients. LDL glycosylation was not able to increase the oxidizability of LDL in the diabetic patients with poor glycemic control.