Increased levels of platelet activation markers are positively associated with carotid wall thickness and other atherosclerotic risk factors in obese patients

The role of platelets in the development of atherosclerosis and obesityrelatedprothrombotic state is still under investigation. In this cross-sectionalcohort study, we measured the levels of different platelet activationmarkers and evaluated their relationship with carotid intimamediathickness (IMT) along with other atherosclerotic risk factors inobese patients with or without atherosclerotic co-morbidities. We enrolled154 obese patients, including 98 with either hypertension, type 2diabetes mellitus or dyslipidaemia, 56 without these co-morbiditiesand 62 age- and sex-matched healthy controls. Platelet P-selectin expressionand the number of platelet-derived microparticles (PMPs)were measured by flow cytometry; soluble P-selectin levels were analysedby ELISA and Thr715Pro P-selectin polymorphism was determinedby PCR-RFLP. Carotid IMT was examined by ultrasonography. The levelsof platelet activation parameters were significantly elevated in allobese subjects with increased carotid IMT compared to healthy con-trols. There was no effect of Thr715Pro genotype on soluble P-selectinlevels in obese individuals contrary to normal subjects. Significant andpositive association was revealed between carotid IMT and plateletP-selectin (p<0.0001), soluble P-selectin (p=0.039) and PMP(p=0.0001) levels. After adjusting for multiple variables, independentassociation was found between soluble P-selectin and fibrinogen(p=0.007), PMP levels and body mass index (p<0.0001) as well as plateletP-selectin and carotid IMT (p=0.012) plus plasminogen activatorinhibitor-1 (p=0.009). In conclusion, P-selectin and PMP levels showedpositive associations with abnormal carotid IMT and other risk factorsin obesity suggesting a critical role of enhanced platelet reactivity inatherosclerotic wall alteration