WHEN AND WHEN NOT TO ASPIRIN

Whether you think you can or whether you think you can't, you're right!

Experts agree that if you survive a heart attack or a clot caused (ischemic) stroke, you should take low dose aspirin. This holds true unless you have an aspirin allergy. In most cases, it also holds true if you have known blockages in the arteries that feed your heart or brain.

But what if you haven't been diagnosed with heart disease or had a stroke? Can an aspirin a day help you, too?

Aspirin reduces the risk of having a heart attack or ischemic stroke. It does this by making platelets in blood less likely to form clots. How much it can help depends on your risk of having a heart attack or stroke.

Aspirin helps a lot if you have already had a heart attack or stroke or if you have partial blockages in your arteries. But if neither of these applies to you, it actually helps very little.

If aspirin had no side effects, then it wouldn't matter whether your risk of heart attack or ischemic stroke was high or low. But we know that is not the case. Even low dose aspirin can cause serious problems. A low dose is generally defined as less than 325 milligrams of aspirin (one regular-strength tablet) daily.

Low dose aspirin can upset the stomach and contribute to the formation of ulcers. The most worrisome side effect is major bleeding. This mainly takes the form of bleeding from the stomach or intestines or bleeding into the brain (called a hemorrhagic stroke).

A new study strongly supports what we have known. Study results appear in the June 6 issue of the Journal of the American Medical Association. The researchers suggest that the prior studies have actually:

Underestimated the risk of major bleeding from low dose aspirin
Overestimated the ability of aspirin to prevent heart attacks and strokes
Another important finding in this study pertains to the benefits and risks of low dose aspirin in people with diabetes. Their baseline risk of major bleeding was found to be 36% higher than that of the general population, whether or not they used aspirin.

So aspirin did not cause people with diabetes to bleed any more than they would if they did not take aspirin. That's good. But wait. Aspirin also did not protect them from strokes and heart attacks as well as it did in the general population. The risks were lower, but so were the benefits.

You would think it's simple to decide about daily low dose aspirin. And for people who have been diagnosed with coronary artery or other blood vessel disease, it is simple. Take a baby aspirin (81 milligrams) daily unless you are allergic.

For everyone else, it gets a bit complicated.

If your heart and arteries are in good shape, consider your heart and blood vessel risk factors. Do you:

Smoke?
Have high blood pressure?
Have a high LDL (bad) cholesterol level?
Have family members with coronary artery disease that started before age 60?

If you answered no to all of the above, you would not take aspirin simply to prevent a heart attack or stroke. However, aspirin may have other benefits. For example, people who take aspirin appear to have a decreased risk of developing cancer, especially colon cancer.

What if you do have one or more of the heart risk factors? Your benefit score goes up with each risk factor you have. If the risk of major bleeding is the same for everyone, your benefit to risk ratio might favour low dose aspirin.

Until recently, daily aspirin was recommended for everyone with diabetes. Now your decision about taking an aspirin is similar to everyone else's. Aspirin is less effective at preventing heart attacks and strokes in people with diabetes. Scientists aren't sure why. Possible reasons include:

Decreased anti-clotting effects of aspirin
Increased platelet turnover in diabetics, therefore increasing the percentage of young, very sticky platelets that would be more aspirin resistant
High blood sugar levels pushing sugar into platelets, which changes how they are affected by aspirin


There will be no simple answer for many of us to the question of "if and when" we should take daily low-dose aspirin. But for people with heart or blood vessel disease or more than two heart risk factors, aspirin benefit will almost always outweigh risk.

The world cares very little about what a man or woman knows; it is what a man or woman is able to do that counts.

THE BACKLASH OF EXERCISE

For some healthy people, exercise may actually increase heart risk, according to a paper published this week in the journal PLoS One.

The review of six previous studies on exercise found that working out worsened at least one measure of heart risk — blood pressure, insulin level or levels of HDL cholesterol or triglycerides — for about 10% of people. About 7% of people declined on at least two measures.

The lead author of the paper, Claude Bouchard, a professor of genetics and nutrition at the Pennington Biomedical Research Center at Louisiana State University, told the New York Times that the finding was “bizarre.”


At the same time, the data, involving 1,687 people, showed that about 10% of people saw outsized gains in at least one measure of heart disease risk — some patients improved 20% to 50%. For other participants, exercise-related rewards ran the gamut, from none to some to significant benefits.

One of the authors of the study was on the committee that provided the scientific evidence underlying the government’s official exercise guidelines for Americans, which recommend at least 150 minutes per week of moderate activity.

The implication here is that the government’s physical activity guidelines are based on rather weak scientific data. The Times’ Gina Kolata writes:

The problem with studies of exercise and health, researchers point out, is that while they often measure things like blood pressure or insulin levels, they do not follow people long enough to see if improvements translate into fewer heart attacks or longer lives. Instead, researchers infer that such changes lead to better outcomes — something that may or may not be true.

Some critics have noted that there is no indication that those who had what Dr. Bouchard is calling an adverse response to exercise actually had more heart attacks or other bad health outcomes. But Dr. Bouchard said if people wanted to use changes in risk factors to infer that those who exercise are healthier, they could not then turn around and say there is no evidence of harm when the risk factor changes go in the wrong direction.

Still, the findings are no excuse not to exercise. For one thing, it’s still not clear why some people had adverse responses to working out. The results couldn’t be explained by how fit participants were (or later became), how strenuously they exercised, whether they were taking medications for blood pressure or cholesterol, or their age, race or gender. “I suspect the most important explanation here will be genomics,” Bouchard told the Boston Globe.

Researchers said it’s important to figure out who will benefit from exercise and who won’t, if we want to able to prescribe exercise individually for better health. “Identifying the predictors of such unwarranted responses and how to prevent them will provide the foundation for personalized exercise prescription,” they wrote.

But for healthy people, experts agree that exercise is a benefit overall. It improves mood, makes you stronger and preserves physical fitness as you age.

So, for now, the authors recommend that people continue exercising as before. If you’ve been sedentary and are starting a new exercise regimen, however, it would be a good idea to check in regularly with your physician to monitor measures of heart health.