Patients with metabolic syndrome exhibit higher platelet activity than those with conventional risk factors for vascular disease.
BACKGROUND
The metabolic syndrome is a matter of ongoing debate with regard to its existence, classification, clinical meaningfulness, and associated risks for vessel occlusion. Considering that persistent platelet activation is a cornerstone for the development of acute vascular events, and that patients with type 2 diabetes consistently exhibit high platelet activity, these characteristics may be critical for distinguishing and triageing specific features of metabolic syndrome among established risk factors for vascular disease.


METHODS
We assessed the platelet activity by conventional aggregation, expression of major surface receptors by flow cytometry, and quantitatively by rapid bedside analyzers in 20 aspirin-naïve patients with documented metabolic syndrome, and compared these with 20 untreated subjects with multiple cardiovascular risk factors.


RESULTS
Closure time by the PFA-100 analyzer was significantly (P = 0.002) shorter in patients with metabolic syndrome indicating platelet inhibition under high shear conditions. Ultegra analyzer readings revealed increased fibrinogen binding (P = 0.0003) what in combination with the increased expression of PAC-1 (P = 0.32) strongly suggest activation of platelet glycoprotein IIb/IIIa receptor. Surface expression of CD107a (P = 0.014), and SPAN-12 (P = 0.003) were also higher in patients with metabolic syndrome. In contrast, platelet aggregation induced by collagen or ADP, CD31, CD41, CD42b, CD51/61, CD62p, CD63, CD154, CD165, so as formation of platelet-monocyte aggregates, PAR-1 thrombin receptor, and thrombospondin did not differ between groups.


CONCLUSIONS
Patients with metabolic syndrome exhibited a higher degree of platelet activation than subjects with conventional risk factors for vascular disease. Conceptually, applying adequate antiplatelet strategies may reduce the risk of acute thrombotic events in these patients. Further prospective studies exploring this notion are encouraged.
Serebruany
Victor L
VL
HeartDrug Research Laboratories, Osler Medical Center, Johns Hopkins University, 7600 Osler Drive, ste.307, Towson, Baltimore, MD 21204, USA. Heartdrug@aol.com
Malinin
Alex
A
Ong
Stephen
S
Atar
Dan
D
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology*; D010979:Platelet Function Tests; D011446:Prospective Studies; D012307:Risk Factors; D014652:Vascular Diseases / Q000503:physiopathology
D015415:Biomarkers