RESUMO
BACKGROUND: Circadian fluctuations in thrombogenicity and hemostasis play a role in acute cardiovascular thrombotic events occurring in the early morning hours. There is a lack of data assessing thrombogenicity, platelet function, and hemodynamics to investigate diurnal variations in a high cardiovascular risk population. METHODS: This was an exploratory, single-center study conducted in aspirin-treated patients with Type II Diabetes Mellitus (T2DM) (n = 37) with documented vascular disease and/or multiple cardiovascular risk factors. Hemodynamic monitoring and blood sample collection for thromboelastography (TEG) and platelet function testing were done serially at 7-9 AM (morning), 7-9 PM (evening), 11 PM-1 AM (night), and at 5-7 AM (awakening). RESULTS: R-value measured by TEG was shorter during awakening hours than during the night and day hours (p < 0.05). There were no changes in platelet reactivity in response to arachidonic acid, adenosine diphosphate, and collagen between time points. Pulse pressure (PP) was highest during awakening hours (p < 0.05). CONCLUSION: Study findings provide a mechanistic explanation for increased thrombotic events observed in the early waking hours among diabetics with multiple cardiovascular risk factors. The role of chronotherapy in reducing coagulability and PP to improve clinical outcomes should be explored.
