Hyperglycemia-Induced Platelet Activation in Type 2 Diabetes Is Resistant to Aspirin but Not to a Nitric Oxide–Donating Agent
- Paolo Gresele, MD, PHD1,
- Stefania Marzotti, MD2,
- Giuseppe Guglielmini, PHD1,
- Stefania Momi, PHD1,
- Silvia Giannini, PHD1,
- Pietro Minuz, MD3,
- Paola Lucidi, MD2 and
- Geremia B. Bolli, MD, PHD2
- 1Section of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Perugia, Italy;
- 2Section of Internal Medicine, Endocrinology and Metabolism, Department of Internal Medicine, University of Perugia, Perugia, Italy;
- 3Department of Biomedical and Surgical Sciences, University of Verona, Verona, Italy.
- Corresponding author: Paolo Gresele, grespa{at}unipg.it.
Abstract
OBJECTIVE Acute, short-term hyperglycemia enhances high shear stress–induced platelet activation in type 2 diabetes. Several observations suggest that platelets in type 2 diabetes are resistant to inhibition by aspirin. Our aim was to assess comparatively the effect of aspirin, a nitric oxide–donating agent (NCX 4016), their combination, or placebo on platelet activation induced by acute hyperglycemia in type 2 diabetes.
RESEARCH DESIGN AND METHODS In a double-blind, placebo-controlled, randomized trial, 40 type 2 diabetic patients were allocated to 100 mg aspirin once daily, 800 mg NCX 4016 b.i.d., both of them, or placebo for 15 days. On day 15, 1 h after the morning dose, a 4-h hyperglycemic clamp (plasma glucose 13.9 mmol/l) was performed, and blood samples were collected before and immediately after it for platelet activation and cyclooxygenase-1 (COX-1) inhibition studies.
RESULTS Acute hyperglycemia enhanced shear stress–induced platelet activation in placebo-treated patients (basal closure time 63 ± 7.1 s, after hyperglycemia 49.5 ± 1.4 s, −13.5 ± 6.3 s, P < 0.048). Pretreatment with aspirin, despite full inhibition of platelet COX-1, did not prevent it (−12.7 ± 6.9 s, NS vs. placebo). On the contrary, pretreatment with the NO donor NCX 4016, alone or in combination with aspirin, suppressed platelet activation induced by acute hyperglycemia (NCX 4016 +10.5 ± 8.3 s; NCX 4016 plus aspirin: +12.0 ± 10.7 s, P < 0.05 vs. placebo for both). Other parameters of shear stress–dependent platelet activation were also more inhibited by NCX 4016 than by aspirin, despite lesser inhibition of COX-1.
CONCLUSIONS Acute hyperglycemia-induced enhancement of platelet activation is resistant to aspirin; a NO-donating agent suppresses it. Therapeutic approaches aiming at a wider platelet inhibitory action than that exerted by aspirin may prove useful in patients with type 2 diabetes.
Footnotes
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- Received October 30, 2009.
- Accepted February 23, 2010.
- © 2010 by the American Diabetes Association.
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