Impact of weight reduction on production of platelet-derived microparticles and fibrinolytic parameters in obesity

INTRODUCTION: Generation of platelet-derived microparticle (PMP) is implicated in cardiovascular disease (CVD). However, the influence of adiposity and weight reduction on PMP generation remains to be fully elucidated. We compared PMP generation and fibrinolytic parameters between 49 non-diabetic obese (obese group) and 37 age-matched non-obese subjects (control group), and compared the effects of weight reduction on the parameters between a 12-week calorie restricted diet and diet with aerobic exercise in obese subjects. MATERIALS AND METHODS: PMP, plasma levels of plasminogen activator inhibitor-1 (PAI-1) activity and tissue-type plasminogen activator (t-PA) antigen were measured before and after intervention. RESULTS: Before intervention, PMP, PAI-1 activity and t-PA antigen values were elevated in the obese group compared with the control group. In all 86 subjects of both groups, these three parameters correlated with body mass index, waist circumference and fat tissue mass. There was a positive correlation between plasma levels of fibrinolytic parameters and visceral fat area (VFA). PMP values correlated with subcutaneous fat area (SFA). The intervention significantly reduced PMP, PAI-1 activity and t-PA antigen levels. There was a significant correlation between percentages of changes in PMP values and those in BMI, fat tissue mass and VFA in the obese group. No additional effect of exercise on PMP or fibrinolytic parameters was observed. CONCLUSIONS: Overproduction of PMP and fibrinolytic abnormalities may be associated with excessive adipose tissue. Weight reduction by either calorie restriction with or without exercise improves fibrinolytic abnormalities and PMP overproduction, probably through reduction of adipose tissue.