Fasting and postprandial glycoxidative and lipoxidative stress are increased in women with type 2 diabetes.

Abstract

We studied acute changes in markers of glycoxidative and lipoxidative stress, including oxidized LDL, N(epsilon)-(carboxyethyl)-lysine (CEL), N(epsilon)-(carboxymethyl)-lysine (CML), and 3-deoxyglucosone (3DG), following two consecutive meals. Postmenopausal women (27 with normal glucose metabolism [NGM], 26 with type 2 diabetes) received two consecutive fat-rich meals and two consecutive carbohydrate-rich meals on two occasions. Glucose and triglyceride concentrations were measured at baseline and 1, 2, 4, 6, and 8 h following breakfast; lunch was given at 4 h. Oxidized LDL-to-LDL cholesterol ratio, CEL, CML, and 3DG were measured at baseline and at 8 h. Fasting oxidized LDL-to-LDL cholesterol ratio, 3DG, and CML were higher in women with type 2 diabetes compared with women with NGM and were comparable to the postprandial values at 8 h in NGM. Postprandial rises in the oxidized LDL-to-LDL cholesterol ratio and 3DG were similar in both groups. However, the oxidized LDL-to-LDL cholesterol ratio increased more after the fat-rich meals, whereas CML and 3DG increased more after the carbohydrate-rich meals. After the fat-rich meals, the increase in the oxidized LDL-to-LDL cholesterol ratio correlated with postprandial triglycerides, whereas the increase in 3DG was correlated with postprandial glucose. The acute changes in markers of glycoxidative and lipoxidative stress in both type 2 diabetes and NGM suggest that postabsorptive oxidative stress may partly underlie the association of postprandial derangements and cardiovascular risk.