ABSTRACT
Objective: To examine the effects of acute hyperglycemic stress on platelet activation by analyzing the plasma levels of P-selectin, beta-thromboglobulin, and platelet indices in an oral glucose tolerance test (OGTT). Material and Methods: The OGTT results were used to form four study groups: a control group (n=31) and a prediabetic group (n=103) comprising three subgroups according to the American Diabetes Association criteria for diabetes. Platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) were determined using the impedance method, and P-selectin and beta-thromboglobulin (β-TG) levels were determined by enzyme-linked immunosorbent assay. P<0.05 was considered significant. Results: No significant difference was observed in the baseline values of PLT, platelet indices, or plasma P-selectin level between the control and prediabetic groups. The baseline plasma β-TG level was significantly higher in the prediabetic group than in the control group (p<0.001). PLT, PCT and P-selectin levels significantly reduced during OGTT in both control (p<0.05 for each) and prediabetic groups (p<0.001 for each). The reduction in PCT (3.88%) and PLT (3.18%) after glucose loading was greater in the prediabetic group than in the control group (2.04% and 1.44%, respectively). The MPV decreased in the prediabetic group (p<0.05), while no significant decrease was observed in the control group. Conclusion: The platelet indices do not change in the prediabetic stage and the initiation of granule activation is independent of platelet morphology. Acute hyperglycemia appears to affect platelet morphology and function in both healthy and prediabetic subjects, and can be marked in prediabetic individuals.