Effects of lipid-lowering treatment on circulating microparticles in patients with diabetes mellitus and chronic kidney disease

Background. Elevated levels of circulating microparticles (MPs) may contribute to the high cardiovascular risk in diabetes mellitus (DM) and chronic kidney disease (CKD). Therefore, we investigated the effects of lipid-lowering treatment (LLT) with simvastatin alone (S) or with ezetimibe (S+E) on MPs in DM patients with or without CKD. Methods. After a placebo run-in period, 18 DM patients with an estimated glomerular filtration rate (eGFR) of 15-59 mL/min (CKD stages 3-4) (DM-CKD) and 21 DM patients with eGFR >75 mL/min (DM-only) were treated with S and S+E in a randomized, double-blind, crossover study. MPs from platelets, monocytes and endothelial cells (PMPs, MMPs and EMPs), and their expression of phosphatidylserine (PS), P-selectin, CD40 ligand (CD40L) and tissue factor (TF) were measured by flow cytometry. Results. At baseline, all types of MPs, except TF-positive MMPs, were elevated in DM-CKD compared with DM-only patients. All MPs, regardless of origin and phenotype, were inversely correlated with eGFR. S reduced the expression of P-selectin, TF and CD40L on PMPs and of TF on MMPs in both patient groups. S+ E had no further effect. S also reduced total PS-positive procoagulant MPs, PMPs and MMPs in DM-CKD but not in DM-only patients. Conclusions. DM patients with CKD stages 3-4 had elevated PMPs, EMPs and MMPs compared with DM patients with normal GFR. Simvastatin reduced procoagulant MPs, MMPs and PMPs in DM-CKD patients, suggesting a beneficial reduction of hypercoagulability in this high-risk patient group. Differences between DM-CKD and DM-only patients were counteracted by LLT.