You are seeing this message because your Web browser does not support basic Web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.


ABOUT JAMA
Advanced Search

Welcome   | My Account | E-mail Alerts | Access Rights | Sign In


  Vol. 295 No. 12, March 22/29, 2006 TABLE OF CONTENTS
  JAMA
  •  Online Features
  Original Contribution
 This Article
 •Full text
 •PDF
 •Send to a friend
 • Save in My Folder
 •Save to citation manager
 •Permissions
 Citing Articles
 •Citation map
 •Citing articles on HighWire
 •Citing articles on ISI (16)
 •Contact me when this article is cited
 Related Content
 •Similar articles in JAMA
 Topic Collections
 •Men's Health, Other
 •Women's Health, Other
 •Alert me on articles by topic

Sex Differences in Platelet Reactivity and Response to Low-Dose Aspirin Therapy

Diane M. Becker, ScD, MPH; Jodi Segal, MD; Dhananjay Vaidya, MD, PhD; Lisa R. Yanek, MPH; J. Enrique Herrera-Galeano, MS; Paul F. Bray, MD; Taryn F. Moy, MS; Lewis C. Becker, MD; Nauder Faraday, MD

JAMA. 2006;295:1420-1427.

Context  Recent randomized trials suggest that women may not accrue the same cardioprotective benefits as men do from low-dose aspirin therapy used in primary prevention. Failure of aspirin to suppress platelet aggregation in women is one hypothesized mechanism.

Objective  To examine differential platelet reactivity to low-dose aspirin therapy by sex.

Design, Setting, and Participants  A clinical trial of aspirin at 81 mg/d for 14 days was conducted in 571 men and 711 women. Baseline and post–aspirin therapy measures included platelet aggregation to arachidonic acid, adenosine diphosphate, epinephrine, and platelet function analyzer closure time.

Main Outcome Measure  Sex differences in cyclooxygenase 1 (COX-1) direct and indirect platelet activation pathways before and after administration of aspirin.

Results  In 10 of the 12 platelet agonist exposures, women's platelets were significantly more reactive at baseline. However, after aspirin therapy, the percent aggregation to arachidonic acid (the direct COX-1 pathway) decreased more in women than in men (P<.001) and demonstrated near total suppression of residual platelet reactivity in both men and women. In COX-1 indirect pathways, women experienced the same or more platelet inhibition than men in 8 of the 9 assays yet retained modestly greater platelet reactivity after aspirin therapy. In multivariable analysis, female sex significantly predicted aggregation to 2 µM and 10 µM of adenosine diphosphate (P = .02 and <.001, respectively) and collagen at 5 µg/mL (P<.001) independent of risk factors, age, race, menopausal status, and hormone therapy.

Conclusions  Women experienced the same or greater decreases in platelet reactivity after aspirin therapy, retaining modestly more platelet reactivity compared with men. However, most women achieved total suppression of aggregation in the direct COX-1 pathway, the putative mechanism for aspirin's cardioprotection.


Author Affiliations: Division of General Internal Medicine (Drs D. M. Becker, Segal, and Vaidya, Mr Herrera-Galeano, and Mss Yanek and Moy), Cardiology Division (Dr L. C. Becker), and Department of Medicine, Department of Anesthesiology and Critical Care Medicine (Dr Faraday), The Johns Hopkins University School of Medicine, Baltimore, Md; and Thrombosis Research Unit, Baylor College of Medicine, Houston, Tex (Dr Bray).



THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

The Role of Aspirin in Cardiovascular Prevention: Implications of Aspirin Resistance
Gasparyan et al.
J Am Coll Cardiol 2008;51:1829-1843.
ABSTRACT | FULL TEXT  

Primary prevention of coronary heart disease in women
Rees et al.
Menopause Int 2008;14:40-45.
ABSTRACT | FULL TEXT  

Individual Heterogeneity in Platelet Response to Lysophosphatidic Acid: Evidence for a Novel Inhibitory Pathway
Pamuklar et al.
Arterioscler. Thromb. Vasc. Bio. 2008;28:555-561.
ABSTRACT | FULL TEXT  

Heritability, Platelet Function, and Aspirin: A Link Established but Cause Unknown
Freedman
Circulation 2007;115:2468-2470.
FULL TEXT  

Heritability of Platelet Responsiveness to Aspirin in Activation Pathways Directly and Indirectly Related to Cyclooxygenase-1
Faraday et al.
Circulation 2007;115:2490-2496.
ABSTRACT | FULL TEXT  

Aspirin Dose for the Prevention of Cardiovascular Disease: A Systematic Review
Campbell et al.
JAMA 2007;297:2018-2024.
ABSTRACT | FULL TEXT  

Aspirin Resistance in Patients with Stable Coronary Artery Disease with and without a History of Myocardial Infarction
Dorsch et al.
The Annals of Pharmacotherapy 2007;41:737-741.
ABSTRACT | FULL TEXT  

CARPHOLOGY by Rajendra
PN 2006;6:268-268.
FULL TEXT  

Review: aspirin was effective for primary prevention of stroke in women and MI in men but increased major bleeding
Thompson
Evid. Based Nurs. 2006;9:76-76.
FULL TEXT  

The Aspirin Resistance Controversy: Clinical Entity or Platelet Heterogeneity?
Freedman
Circulation 2006;113:2865-2867.
FULL TEXT  

Four Studies on Cardiac Health in Women
Journal Watch Cardiology 2006;2006:6-6.
FULL TEXT  

Women's Health--Advances in Knowledge and Understanding
DeAngelis and Glass
JAMA 2006;295:1448-1450.
FULL TEXT  





HOME | CURRENT ISSUE | PAST ISSUES | TOPIC COLLECTIONS | CME | SUBMIT | SUBSCRIBE | HELP
CONDITIONS OF USE | PRIVACY POLICY | CONTACT US | SITE MAP
 
© 2006 American Medical Association. All Rights Reserved.