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Thrombosis as the main complication of coronary heart disease (CHD) represents the primary cause of morbidity and mortality in patients with diabetes mellitus (DM). In the course of diabetes mellitus some coagulation abnormalities occur, that may result in a thrombogenic propensity. Aspirin (ASA) as a platelet-inhibiting agent through inactivation of Cyclooxygenase-1 (COX-1) is mostly used for the prevention and treatment of atherothrombotic disorders. ASA inhibits the COX-1 enzyme and therefore blocks platelet thromboxane A2 (TXA2) synthesis. However, some of the serious vascular events in high-risk vascular patients are attributable to a failure of ASA to suppress platelet aggregation. The consumption of antioxidant or antioxidant rich foods such as vitamin C, E, and polyphenols might impart anti-thrombotic and cardiovascular protective effects via their inhibition of platelet hyper-activation or aggregation similar to the action of aspirin. This review will discuss the risk of thrombosis in diabetes, what aspirin resistance means, and the effectiveness of antioxidant therapy in the prevention and possible treatment of atherothrombotic disorders. [ABSTRACT FROM AUTHOR]

Gilbert's syndrome (GS) is a relatively common condition, inducing a benign, non-hemolytic, unconjugated hyperbilirubinemia. Gilbert's Syndrome is associated with mutation in the Uridine Glucuronosyl Transferase 1A1 (UGT1A1) gene promoter, reducing UGT1A1 activity, which normally conjugates bilirubin allowing its elimination from the blood. Individuals with GS demonstrate mildly elevated plasma antioxidant capacity caused by elevated levels of unconjugated bilirubin (UCB), reduced thiols and glutathione. Interestingly, the development of, and risk of mortality from, cardiovascular disease is remarkably reduced in GS individuals. An explanation for this protection may be explained by bilirubin's ability to inhibit multiple processes that induce platelet hyper-reactivity and thrombosis, thus far under-appreciated in the literature. Reactive oxygen species are produced continuously via metabolic processes and have the potential to oxidatively modify proteins and lipids within cell membranes, which may encourage the development of thrombosis and CVDs. Oxidative stress induced platelet hyper-reactivity significantly increases the risk of thrombosis, which can potentially lead to tissue infarction. Here, we discuss the possible mechanisms by which increased antioxidant status might influence platelet function and link this to cardiovascular protection in GS. In summary, this is the first article to discuss the possible role of bilirubin as an anti-thrombotic agent, which inhibits platelet activation and potentially, organ infarction, which could contribute to the reduced mortality rate in mildly hyperbilirbinemic individuals. [ABSTRACT FROM AUTHOR]

Gilbert’s syndrome (GS) is associated with a mild unconjugated hyperbilirubinemia, increased circulating antioxidant capacity, and reduced cardiovascular disease (CVD) risk. The current study investigated whether mildly elevated circulating unconjugated bilirubin (UCB) is negatively associated with multiple thrombotic risk factors including platelet activity, hemostatic function, and inflammation in individuals with GS. Blood samples were collected from matched GS and control subjects (14 per group). Activation-dependent platelet surface marker expression of PAC-1 (binds to GPIIb/IIIa surface receptors on activated platelets) and CD62P (marker for P-selectin released from activated degranulated platelets) was assessed in adenosine diphosphate (ADP)-stimulated platelets using flow cytometry. Exogenous agonists, ADP, collagen, and arachidonic acid (AA), were used to stimulate platelet aggregation. A statistically significant decrease in the expression of P-selectin (P= 0.030) on activated platelets was observed in GS subjects. Collagen and AA-induced platelet aggregation were significantly (P =0.018;P= 0.032 for respective agonists) reduced in GS versus control group. Elevated UCB (P= 0.001) and high density lipoprotein (P= 0.033) in addition to reduced low density lipoprotein (P= 0.024) and high sensitive C-reactive protein (P =0.043) were also observed in GS when compared to the control group. Reduced P-selectin expression suggests decreased platelet activation-dependent degranulation, while reduced platelet aggregation by AA and collagen indicates a quantitative decrease in platelet aggregation consequently targeting the cyclooxygenase-1 and GP VI pathways, respectively. These findings are the first to demonstrate that the activation of platelets is mildly inhibited in individuals with GS, an effect that might contribute to protection from platelet hyperactivation-induced thrombosis and thus cardiovascular mortality in individuals with benign hyperbilirubinemia. [ABSTRACT FROM AUTHOR]

One of the most commonly identified chronic illnesses in many countries is type 2 diabetes mellitus (T2DM). T2DM denotes an independent risk factor for cardiovascular disease (CVD). Heart disease is one of the causes of mortality in patients with diabetes, mainly due to the macrovascular complications. One of these macrovascular complications in diabetes is atherosclerosis, which involves a complicated pathophysiological process. Besides hyperglycemia, oxidative stress plays a significant role in the pathogenesis of diabetes and its associated risk of CVD. There are many other factors including molecular, metabolic, lipid, fibrinolytic, and platelet function disorders precipitate to thrombotic and CVD risks in T2DM. Also, Platelets have an increased response to procoagulants in patients with diabetes. Platelet hyperactivity, in the presence of oxidative stress, has a major effect on the progression of thrombotic and CVD events. This review will discuss the impact of the above factors and the potential effects of platelet hyperactivity on thrombotic and cardiovascular risks. [ABSTRACT FROM AUTHOR]