We evaluated the plasma concentrations of soluble adhesion molecules, platelet activation markers, and platelet-derived microparticles (PMPs) in patients with connective tissue diseases who had secondary hyperlipidemia caused by long-term steroid administration (n = 22) before and after treatment with bezafibrate. There were differences in levels of platelet activation markers both before and after treatment (platelet CD62p: 15.11+/-2.03 vs 10.38+/-8.53%, P < 0.05; platelet CD63: 12.12+/-9.17 vs 9.90+/-7.20%, P < 0.05). There were also differences in the levels of PMPs and soluble adhesion molecules both before and after treatment (PMP: 514+/-273 vs 401+/-201 /10(4) platelet. P < 0.05; soluble vascular cell adhesion molecule-1: 724+/-191 vs 666+/-157 ng/mL, P < 0.01). After 6 months of treatment, serum lipid concentrations were reduced by 9% for total cholesterol (TC) and 32% for triglyceride (TG). The level of PMPs, activated platelets, and soluble adhesion molecules were all significantly decreased after treatment with bezafibrate. These findings suggest that bezafibrate may be useful for inhibiting both PMP-dependent and -independent vascular damage in patients with connective tissue diseases complaining of secondary hyperlipidemia.