RESUMO
AIMS: Platelet activation is known to be associated with arrhythmic effects in myocardial ischaemia. The present study attempts to clarify whether diabetic cardiovascular autonomic neuropathy (CAN) is associated with intravascular platelet activation. METHODS: Platelet activation was assessed by flow cytometry analysis in 30 patients with Type 1 diabetes mellitus screened for diabetic complications. Fifteen patients showed evidence of CAN as assessed by a battery of standard cardiovascular autonomic reflex tests. Fifteen patients without CAN were then selected as a matched control group. Platelet activation was assessed by flow cytometric detection of activation-dependent platelet membrane antigens (P-selectin (CD62), thrombospondin, lysosomal GP53 (CD63) and ligand-induced binding site-1 of GPIIb/IIIa (LIBS-1)). RESULTS: Significantly more activated platelets were detected in the patients with CAN showing 20.9% (coefficient of variation (CV) 44%) CD63+ (vs. 17.2% (CV 19%) in controls, P < or = 0.05), 6.4% (CV 87%) CD62+ (vs. 4.1% (CV 37%), P < or = 0.05), and 6.7% (CV 55%) thrombospondin+ (vs. 4.6% (CV 39%), P < or = 0.01) platelets, respectively. LIBS-1 on platelets was not significantly different between patients with and without CAN. No correlation was found between glucose metabolism and platelet activation. CONCLUSIONS: Cardiovascular autonomic neuropathy is associated with platelet activation in Type 1 diabetes mellitus. The high platelet activation may reflect an increased prothrombotic state in diabetic cardiovascular autonomic dysfunction.
