Patients with type 2 diabetes but without existing cardiovascular disease experienced a time-dependent increase in platelet aggregation in the 24 hours after once-daily aspirin therapy, suggesting that a twice-daily aspirin regimen could provide CV benefit, study data show.
“The antiplatelet effects of aspirin do not last for the standard 24-hour dosing interval, and patients with type 2 diabetes have alterations in their platelet function,” Liv Vernstrøm, a master’s student in the department of endocrinology and internal medicine at Aarhus University in Denmark, told Endocrine Today. “Perhaps the alterations seen in platelet function in patients with type 2 diabetes could be related to their increased risk for CVD. Further, they might benefit from an alternative dosing regimen when it comes to treatment with aspirin. Our data indicate that a twice-daily dosing could add additional benefits, but this needs to be studied further.”
In an open-label, parallel group study, Vernstrøm and colleagues analyzed data from 21 patients with type 2 diabetes and 21 age- and sex-matched controls who received once-daily aspirin for 6 days (mean age, 62 years; 67% men; mean diabetes duration, 9 years). Participants provided blood samples 1 hour and 24 hours after aspirin intake. Platelet aggregation was measured by impedance aggregometry using arachidonic acid and thrombin receptor-activating peptide as agonists; platelet turnover markers were measured by flow cytometry.
At 6 days, researchers found that platelet aggregation levels increased during the 24-hour dosing interval in patients with diabetes (mean, 85 aggregation units per minute) and controls (mean, 80 aggregation units per minute).
At baseline, researchers observed increased platelet aggregation in patients with diabetes vs. controls (mean, 949 vs. 835; P = .03), and platelet aggregation numbers fell further after the first dose of aspirin for both groups while remaining higher in patients with type 2 diabetes (mean, 731 vs. 634). Numbers were further reduced after 6 days of treatment in both groups (mean, 172 vs. 215).
Researchers also observed a greater number of immature platelets in patients with type 2 diabetes vs. controls (mean, 8 109/L vs. 5.9 109/L), which points to increased platelet turnover. However, the finding was not statistically significant.
“Given that platelets in people with diabetes are characterized by increased aggregation and increased turnover rates, our study indicates that patients with type 2 diabetes may achieve additional benefit from twice-daily rather than once-daily dosing of aspirin,” the researchers wrote in a press release. “Large-scale clinical outcome trials are needed to confirm the safety and efficacy of this approach.”
The researchers noted that the observed increased baseline aggregation in patients with diabetes has not been shown previously, and it confirms alterations in platelet function in patients with type 2 diabetes.
“This could be related to the increased risk of CVD in patients with type 2 diabetes; however, this needs further evaluation,” they wrote. – by Regina Schaffer
Vernstrøm L, et al. Abstract 1132. Presented at: European Association for the Study of Diabetes Annual Meeting; Sept. 11-15, 2017; Lisbon, Portugal.
Disclosure: Vernstrøm reports no relevant financial disclosures.