Decreased release of lipoprotein lipase is associated with vascular endothelial damage in NIDDM patients with microalbuminuria

OBJECTIVE - To explore mechanisms for hypertriglyceridemia in diabetic patients with microalbuminuria, we examined an association between heparin-releasable lipoprotein lipase (LPL) and the von Willebrand factor (VWF), based on the hypothesis that LPL bound to endothelium is decreased by generalized endothelial damage. RESEARCH DESIGN AND METHODS - A total of 37 NIDDM patients with microalbuminuria and 69 patients with normoalbuminuria were studied. Plasma LPL mass in postheparin plasma and plasma vWF antigen were quantified by sandwich-enzyme immunoassay and enzyme-linked immunosorbent assay, respectively. RESULTS - The NIDDM patients with microalbuminuria had higher plasma triglyceride (TG) and lower HDL cholesterol concentrations compared with the patients with normoalbuminuria. Heparin-releasable LPL mass was significantly lower in the microalbuminuric than in the normoalbuminuric subjects. Plasma level of vWF; a marker for endothelial damage, was significantly increased in microalbuminuric subjects compared with their normoalbuminuric counterparts. The LPL mass was inversely correlated with plasma vWF level at a high correlation coefficient value. The LPL mass was inversely related to TG and positively to HDL cholesterol concentrations. CONCLUSIONS - These results suggest that widespread endothelial damage occurred in NIDDM patients with microalbuminuria, thereby LPL moiety bound to the endothelium is decreased, which results in an impaired catabolism of TG-rich lipoproteins.