BACKGROUND: Type-2 diabetes mellitus (T2DM) is an isolated risk factor for coronary artery disease, especially when associated with microalbuminuria (MA). Structural and functional changes in lipoproteins have not yet been fully elucidated in this context. OBJECTIVE: To assess lipid transfer (T) to HDL in type-2 diabetic patients and its association with microalbuminuria and treatment with statins or insulin. METHODS: Thirty-three patients with type-2 diabetes mellitus and 34 age-matched control subjects were studied. A synthetic cholesterol-rich nanoemulsion radiolabeled with ³H- triglycerides (TG) and 14C-free cholesterol (FC) or ³H- cholesteryl ester (CE) and 14C-phospholipids (PL) was incubated with plasma. Both the nanoemulsion and lipoproteins were precipitated, except for HDL, which was counted for radioactivity. RESULTS: PLT (%) was higher in the T2DM group than in the control group (25.2 ± 3.2 and 19.7 ± 3.2 respectively; p < 0.001), as was free cholesterol (% FC): 9.1 ± 2.7 and 6.3 ± 1.5 respectively; p < 0.001. The diagnosis of microalbuminuria (MA) was not associated with changes in lipid transfers. Insulin therapy was associated with lower PLT rates: 23.5 ± 2.1 versus 26.1 ± 3.3; p = 0.018. Statin therapy, in turn, was associated with a drop in all lipid transfers - CET 3.5 ± 0.9; PLT: 23.8 ± 2.0; TGT: 3.9 ± 0.8; FCT: 7.4 ± 1.3 - as compared to the group that was not on statin therapy (CET: 5.9 ± 2.4; PLT: 26.9 ± 3.6; TGT: 6.4 ± 2.2; FCT: 11.1 ± 2.6). CONCLUSION:Type-2 diabetes mellitus increased lipid transfer to HDL particles, whereas statin therapy decreased all lipid transfers. The presence of MA was not associated with changes in lipid transfer.
Cholesterol, HDL; lipoproteins; diabetes mellitus, type 2; insulin; hydroxymethylglutaryl-CoA reductase inhibitors; albuminuria; diabetic nephropathies
