Activated platelets in patients with severe hypertriglyceridemia: effects of triglyceride-lowering therapy

Hypertriglyceridemia, a risk factor for cardiovascular disease, has been as sociated with hypercoagulability, but whether platelet activation is implic ated is unknown. This study was designed to compare the in vivo platelet ac tivation status between patients with severe hypertriglyceridemia and age- and sex-matched control subjects, and to evaluate the effects of triglyceri de-lowering therapy. Sixteen patients with primary hypertriglyceridemia wer e included in a double-blind, placebo-controlled cross-over trial with 400 mg bezafibrate once daily. Platelet activation was analysed by double label flow cytometry, using monoclonal antibodies against GP53, P-selectin, and platelet-bound fibrinogen. Surface expression of the lysosomal membrane pro tein GP53 was significantly higher in the hypertriglyceridemic patients at baseline as compared to the group of age- and sex-matched controls (16.3 +/ - 4.8% vs. 8.9 +/- 3.4%, respectively, P<0.001). No differences in the expr ession of P-selectin and fibrinogen binding were observed. In response to b ezafibrate therapy, the expression of GP53 in the patient group decreased f rom 16.3 +/-4.8% to 13.1+/-4.1% (P= 0.018). The expression of P-selectin an d fibrinogen binding was not affected by bezafibrate therapy. In conclusion , patients with hypertriglyceridemia have an increased in vivo platelet act ivation status, which can be improved by bezafibrate therapy. (C) 2000 Else vier Science Ireland Ltd. All rights reserved.