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 microg/mg of
creatinine), and high (101-300 microg/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.