Increased Plasma Glycated Low-Density Lipoprotein Concentrations in Diabetes: A Marker of Atherogenic Risk

Abstract

Nonenzymatic glycation of apolipoprotein B in the low-density lipoprotein (LDL) complex has been considered a proatherogenic modification contributory to the increased susceptibility of patients with diabetes to atherosclerosis. We postulated that glycated LDL concentrations might be associated with other markers of cardiovascular disease. To explore this hypothesis, we measured glycated LDL concentrations by a monospecific immunoassay in 50 patients with type 1 and 100 patients with type 2 diabetes and examined relationships with the amount of albumin excretion and the serum cholesterol and triglyercide concentrations. Plasma glycated LDL showed a significant positive correlation (r = 0.325; P < 0.001) with urinary albumin excretion that was higher in type 1 (r = 0.463) than in type 2 (r = 0.245) patients. The mean glycated LDL concentration progressively increased with increasing albumin excretion when patients were subcategorized into groups of normoalbuminuria, low (≤100 μg/mg of creatinine), and high (101-300 μg/mg) microalbuminuria, and proteinuria. Glycated LDL also correlated positively and significantly with cholesterol (r = 0.578) and triglyceride (r = 0.350) concentrations. The significant correlations in this cross-sectional analysis between glycated LDL and urinary albumin excretion, an index of cardiovascular mortality, and cholesterol and triglyceride concentrations, traditional markers of risk for cardiovascular disease, support the hypothesis that an elevated level of glycated LDL represents an atherogenic risk factor in patients with diabetes.