Abstract 639: Visfatin, a Novel Adipocytokine, Mediated Activation of Human Platelets in Obese Individuals.
Background Obesity is associated with insulin resistance, accelerated atherothrombosis, and cardiovascular diseases. Visfatin, a newly recognized adipocytokine, has been isolated from visceral fat deposits. It has been shown to activate insulin receptors. But role of visfatin for atherosclerosis is still unclear. The insulin receptor is present on adipose tissue but also on platelets ant other cells. In insulin-resistant patients, platelet inhibition by insulin is attenuated or absent, suggesting that in healthy individuals insulin signals suppress platelet activation. To understand the role of visfatin in platelet activation, we investigated the effect of visfatin on ADP-induced platelet activation of obese individuals.
Methods and Results Obese volunteers and non-obese healthy controls claimed not to have any cardiovascular disease and any medicine were recruited into this study. The baseline aggregation response to ADP was higher in obese platelets (P<0.01). Pre-incubated with visfatin, inhibition of ADP-induced aggregation was observed in healthy control, but absent in obese individuals. Expression of platelet P-selectin in unstimulated samples was not significantly altered by visfatin in both obese and control group. However, ADP-induced platelet P-selectin expression was enhanced by visfatin in obese group (Figure⇓).
Conclusion Here we have demonstrated the first evidence of visfatin mediated platelet activation in obese individuals. Our data indicate a new role of visfatin as a prothrombotic factor.