Navigation Links
Low-dose Aspirin Benefits Both Sexes

A daily low-dose of Aspirin can lower clot formation in both men and women according to a new study from John Hopkins//.

A direct comparison of blood cell testing in both sexes with 81 milligrams of acetyl salicylic acid a day, resulted in prevention of clumping together of platelets – the clot-forming cells. Clots in blood vessels of the heart and brain cause heart attacks and strokes.

However, while the drug's overall effects on blood cell function were the same for men and women, the investigators found that women's platelets reacted somewhat more strongly to aspirin before the start of therapy, and remained so even after treatment.

The study findings appear in the Journal of the American Medical Association online March 21, and challenge the conclusions from several other recent studies, including the federal Women's Health Study, which showed low-dose aspirin had no effect in preventing heart attacks in women, even though it worked in men. Previous results, the researchers say, were not likely caused by the failure of aspirin to prevent platelets from clumping together and forming blood clots in women.

"Women are clearly benefiting from taking aspirin and should continue to take it to improve their cardiovascular health," says study senior investigator Diane Becker, M.P.H., Sc.D., a professor at The Johns Hopkins University School of Medicine and Bloomberg School of Public Health. "Aspirin has been proven by all previous studies to lower the risk of stroke and, as our latest findings show, it also reduces platelet aggregation that can lead to potentially fatal clots in blood vessels."

"Our results show that aspirin does what it is supposed to do in both men and women," says platelet biologist and study co-author Nauder Faraday, M.D., an associate professor at Hopkins. "But women started at a higher baseline level of platelet aggregation and remained slightly higher even after taking aspirin. So, it remains uncl ear if the residual differences in platelet function impact the drug's overall beneficial effects, and if the doses used in earlier studies were sufficient to decisively prevent heart attacks in women.

"Further research is required to get a definitive answer as to whom aspirin really benefits, under what circumstances it does work and does not work, and just how much is required in different people," he adds.

Results in both men and women showed that aspirin, taken daily for a two-week period, works by inhibiting key biological pathways that lead to platelet clumping.

Moreover, platelet aggregation was largely suppressed in at least three other key pathways related to their function when platelets were stimulated with substances that normally trigger clot formation. Each of these tests involved mixing whole blood, or platelet-rich plasma, from aspirin-treated men and women with various concentrations of each of the main chemical compounds involved in the pathways - collagen, adenosine diphosphate, and epinephrine - to see how platelets responded.

For example, in aspirin-treated men, platelet clumping went down by 14.6 ohms when 1 microgram of collagen per milliliter was added to whole blood, and decreased by 2.4 ohms when exposed to a higher dose of 5 micrograms per milliliter. In treated women, reductions were the same, at 14.9 ohms and 2.42 ohms, respectively.

When 10 micromoles per liter of adenosine diphosphate were added to whole blood, platelet aggregation decreased the same amount, 0.19 ohms in men and 0.21 ohms in women. Addition of 2 micromoles per liter of epinephrine to platelet-rich plasma produced significantly greater reductions in platelet clumping in treated women, a drop of 36.9 percent, while it was less of a reduction for men, at 31.5 percent. Again, the researchers say, these changes would have been zero if aspirin had had no effect.

Further analysis of results highlighted mainly two fac tors, platelet reactivity levels before therapy starts and gender, as having played a significant role in predicting the effects of aspirin therapy on platelet clumping. Other factors, such as age, race or known risk factors for heart disease, including smoking, obesity and high blood pressure, were not found to be good predictors of aspirin's beneficial effects.

More than 500 men and 700 women participated in the study, called the Genetic Study of Aspirin Responsiveness (GeneSTAR). Conducted solely at Hopkins from June 2004 to November 2005, the study enrolled participants from across the country who ranged in age from 21 to 80; 31 percent were black and the rest were white. None had previous histories of heart problems, such as a heart attack, but all were considered to be at slightly increased risk of heart disease because of a family history. Fifty percent of women participants were postmenopausal.

Blood testing was conducted both before and after treatment. In total, more than 200 different tests of platelet reactivity were performed and analyzed in the study. Because whole blood contains other cells that affect platelet aggregation, testing was repeated using a purified version of test samples made up of strictly platelet-rich plasma.

At the start of the experiment, laboratory tests of blood platelets in women were found four times more likely than in men to aggregate when exposed to arachidonic acid, a clot-inducing chemical in the pathway that is most suppressed by aspirin.

While taking aspirin, participants maintained a strict and consistent dietary and exercise regimen, with no smoking or consumption of foods that by themselves affect platelet activity, such as caffeine, chocolate, wine or grapefruit juice. Physical examinations and pill counts were conducted to ensure that all participants adhered to the study protocol. Because aspirin reaches its maximal effect in the body at five days, the researchers say a longer study testing period was not required to determine the drug's effects on platelet function.

Funding for the study was provided by the National Heart, Lung and Blood Institute, a member of the National Institutes of Health, and the Johns Hopkins Clinical Research Center.

Besides Becker and Faraday, other investigators in this research were Jodi Segal, M.D.; Dhananjay Vaidya, M.D., Ph.D.; Lisa Yanek, M.P.H.; J. Enrique Herrera-Galeano, M.S.; Paul Bray, M.D.; Taryn Moy, M.S.; and Lewis Becker, M.D.

Contact: David March
Johns Hopkins Medical Institutions

Related medicine news :

1. Low-dose Growth Hormone (GH) with diet and exercise may help weight loss
2. Low-dose Aspirin Beats High-dose After Cardiac Surgery
3. Low-dose Omega-3 Linked to Lower Blood Pressure
4. Clinical Trials for a Low-dose Steroid Therapy for Bone Marrow Cancer Prove Positive
5. What happens when Asthmatics consume Aspirin?
6. Aspirin reduces deaths
7. Aspirin and Warfarin Are Equally Effective for Stroke Prevention
8. Aspirin - a drug after one’s own hear
9. Aspirin deflated
10. Aspirin surpasses Modern Anti-clotting Drugs
11. Night Time Aspirin Regimen Found to Reduce Blood Pressure
Post Your Comments:

(Date:6/26/2016)... ... June 26, 2016 , ... Pixel Film Studios Released ProSlice ... "Film editors can give their videos a whole new perspective by using the ... of Pixel Film Studios. , ProSlice Levels contains over 30 Different presets to ...
(Date:6/25/2016)... D.C. (PRWEB) , ... June 25, 2016 , ... ... discuss health policy issues and applications at AcademyHealth’s Annual Research Meeting June 26-28, ... their work on several important health care topics including advance care planning, healthcare ...
(Date:6/25/2016)... TX (PRWEB) , ... June 25, 2016 , ... ... the United States, named Dr. Sesan Ogunleye, as the Medical Director of its new ... the facility Medical Director of our new Mesquite location,” said Dr. James M. Muzzarelli, ...
(Date:6/25/2016)... Montreal, Canada (PRWEB) , ... June 25, 2016 , ... ... the pursuit of success. In terms of the latter, setting the bar too high ... low, risk more than just slow progress toward their goal. , Research from ...
(Date:6/24/2016)... PASADENA, CA (PRWEB) , ... June 24, 2016 , ... Marcy was in a crisis. ... he would lash out at his family verbally and physically. , “When something upset him, ... table, he would use it. He would throw rocks at my other children and say ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... INDIANAPOLIS , June 23, 2016 /PRNewswire/ ... Diabetes Tomorrow,s Leaders Scholarship is any indication, the future ... today online at by the Diabetes ... stand in the way of academic and community service ... scholarship program since 2012, and continues to advocate for ...
(Date:6/23/2016)...  Guerbet announced today that it has been named ... . One of 12 suppliers to receive ... support of Premier members through exceptional local customer service ... to lower costs. ... outstanding customer service from Premier," says Massimo Carrara ...
(Date:6/23/2016)... FRANKLIN, Tenn. , June 23, 2016 ... for automating, integrating and transforming the patient ... launch of several innovative new products and ... depth of its revenue cycle offerings. These ... establish more efficient workflows, remain compliant in ...
Breaking Medicine Technology: