The recommendation that certain people take a daily low dose of aspirin to prevent a heart attack has been around for a while now. But it’s still not entirely clear which people would benefit the most – or at all – from taking a daily aspirin and which may get no significant benefit.
The American Diabetes Association (ADA) currently recommends a daily low dose of aspirin (75—162 milligrams) for the following groups:
- People with diabetes who have already had a heart attack or stroke or who have been diagnosed with some form of cardiovascular disease (such as atherosclerosis or peripheral arterial disease)
- People with diabetes (Type 1 or Type 2) who are at increased risk of developing cardiovascular disease because they are over 40, have a family history of heart disease, smoke, have high blood pressure or a blood lipid (cholesterol and triglyceride) disorder, or have albuminuria (protein in the urine). (Click here to learn about risk factors for heart disease.)
The ADA makes these recommendations because people with diabetes generally have a risk for cardiovascular disease that is two to four times greater than that of the rest of the American population. In addition, people with diabetes tend to have increased “platelet aggregation,” which means that their blood is more likely to clot abnormally, which can lead to a heart attack or stroke. Aspirin decreases blood clot formation, therefore lowering these risks.
In all cases, however, a person should talk to his doctor before starting to take daily aspirin. Having certain medical conditions (besides diabetes) and/or taking certain medicines that interfere or interact with aspirin may make it unsafe for some individuals.
Aspirin belongs to the class of drugs known as nonsteroidal anti-inflammatory drugs, or NSAIDs. It is commonly used to relieve mild to moderate aches and pains, such as headache or sore throat, and to reduce fever.
Aspirin is sold over the counter as a generic product and under many brand names in a number of forms: tablets, caplets, gelcaps, chewable tablets, suppositories, enteric-coated tablets (which have a barrier applied to the outer surface that prevents the release of the drug until it reaches the small intestine), and buffered tablets (which contain ingredients to reduce stomach acid). (To learn about some commonly used low-dose aspirin products, click here.) Aspirin is also an ingredient in some combination medicines. The dose of aspirin per tablet, caplet, etc., can range from 75 milligrams (mg) to 650 mg.
Because the most common side effect of routine aspirin use is irritation of the stomach lining, some physicians prefer enteric-coated or buffered aspirin for daily aspirin therapy. Taking aspirin with food, milk, or a full glass of water can also help minimize stomach irritation.
When taking aspirin on a daily basis, it is generally best to take it at the same time each day. Avoid taking it with other NSAIDs, such as ibuprofen (brand name Advil and others), naproxen (Aleve, Naprosyn), and diclofenac (Voltaren); doing so may make one or both of the drugs less effective or increase the risk of side effects. If you must take both aspirin and ibuprofen, either take ibuprofen 8 hours before aspirin or 30 minutes after non-enteric-coated aspirin. The NSAID celecoxib (Celebrex) can be used at the same time as low-dose aspirin, but doing so increases the risk of gastrointestinal bleeding.
Aspirin does degrade over time, and it degrades faster if exposed to warm, humid air. If your bottle of aspirin has passed its expiration date or smells like vinegar, discard it. It may no longer be effective.
Preventing heart attack
Blood is made up of red and white blood cells, plasma (the liquid part), and small, sticky particles called platelets. Normally, platelets help to heal wounds by causing the blood to clot at the site of an injury. However, in people with diabetes, platelets tend to be too sticky and more likely to form clots that are not beneficial. Such clots can lead to heart attack or stroke. (Click here to find out what to do if you think you’re having a heart attack.) Regular aspirin use “thins” the blood, so that platelets are less likely to stick together and form clots.
Some recent studies have questioned how well aspirin therapy prevents heart attack in people with diabetes.
One study, published in October 2008 in the journal BMJ and called “The Prevention of Progression of Arterial Disease and Diabetes,” was conducted at the University of Dundee in Scotland. It looked at 1,276 men and women who had never had a heart attack or stroke but were at high risk because they had either Type 1 or Type 2 diabetes, were age 40 or older, and had peripheral arterial disease. The researchers wanted to see if 100 mg of aspirin daily helped prevent “cardiovascular events” (such as heart attack or stroke) in the study participants. Some of the study participants took an aspirin a day, and some took a placebo (an inactive pill). After eight years, the researchers found that the number of heart attacks and strokes was about the same in the aspirin group as it was in the placebo group.
However, the researchers noted that several earlier studies have established the effectiveness of daily aspirin in reducing the risk of another heart attack or stroke among men and women with diabetes who have already had a heart attack or stroke. They concluded that aspirin should still be given for prevention of heart attacks in people with diabetes with diagnosed cardiovascular disease.
Another recent study, published in The Journal of the American Medical Association in November 2008 and called the “Japanese Primary Prevention of Atherosclerosis With Aspirin for Diabetes” trial, examined whether daily aspirin therapy prevented first cardiovascular events in Japanese people with Type 2 diabetes and no history of heart disease. In this study there were 2,539 participants, and the study lasted for about four years. At the end of the study, the re-searchers observed no significant difference in the number of first-time cardiovascular events in the two groups. But they did note that among study participants aged 65 and older, the risk of cardiovascular events decreased by 32%. Still, the researchers cautioned that the study results had to be looked at in context, and that the overall rate of initial cardiovascular events was relatively low.
The conclusions of these two studies are consistent with previous studies that have found little benefit to taking low-dose aspirin for people with diabetes who do not already have cardiovascular disease. However, some experts believe that larger studies of longer duration that use a higher dose of aspirin are needed to settle the question of whether aspirin can prevent new cardiovascular disease in people, and specifically Americans, with diabetes.
At present, two larger-scale studies of the effects of aspirin – one with locations in the United States – are recruiting individuals with diabetes to participate. It is hoped that these studies will better establish the risks and benefits of aspirin in people with diabetes at moderate to high risk of a first heart attack or stroke.
Who should not take aspirin?
While a daily low dose of aspirin is safe for many people, for some people it is not, and some may have a higher risk of stomach irritation than others. For these reasons, everyone should check with his doctor before starting daily aspirin use.
The more aspirin you take, the higher your risk of stomach ulceration or bleeding. That’s why it’s important to be aware of aspirin as an ingredient in combination medicines, so you can accurately assess your daily intake. Other NSAIDs can also cause gastrointestinal bleeding, so if you take other NSAIDs as well as aspirin, your risk of bleeding increases.
Drinking alcohol also raises the risk of stomach irritation and bleeding, so if you have a history of alcoholism or drink more than three servings of alcohol daily, your health-care provider may advise against daily aspirin use.
Your risk of stomach irritation and bleeding is also higher if you have a history of gastroesphageal reflux disease (GERD) or stomach ulcers, take steroids such as prednisone, smoke, or are over 60 years old. You may still be able to take aspirin, but your doctor may advise you to also take a drug called a proton-pump inhibitor to decrease the amount of acid in your stomach.
Aspirin is generally not recommended if you have gout.
Aspirin and other NSAIDs are not recommended if you have kidney disease.
Aspirin should not be taken if you have active liver disease.
Aspirin should not be given to children and teenagers who have a fever because of the associated risk of Reye syndrome (a serious disease). (Daily aspirin therapy is not recommended for anyone under 21 in any case.)
Always check with your health-care provider before using any product that contains aspirin if you are taking a blood thinner (also referred to as an anticoagulant or antiplatelet medicine). Anticoagulants include pills such as warfarin (Coumadin, Jantoven) and injections such as heparin and low-molecular-weight heparins, which include enoxaparin (Lovenox), tinzaparin (Innohep), and dalteparin (Fragmin). Antiplatelet medicines include NSAIDs as well as clopidogrel (Plavix), ticlopidine (Ticlid), dipyridamole (Persantine), and combined dipyridamole and aspirin (Aggrenox).
You should also check with your doctor before using aspirin if you are pregnant or are breast feeding or if you have asthma, kidney problems, or a history of bleeding problems. In addition, let your physician know you are taking aspirin if you are scheduled for any type of medical, dental, or surgical procedure.
Last, if you notice any of the following symptoms, stop taking aspirin and call your doctor right away: severe stomach pain; coughing up blood; vomit that looks like coffee grounds; black, tarry, or bloody stools; skin rash or hives with intense itching; swelling of the face or eyelids; wheezing or trouble breathing; severe dizziness or drowsiness; any type of ringing in your ears.
One piece of the puzzle
If you are currently taking an aspirin a day under your doctor’s orders, don’t stop. It could be preventing a heart attack or stroke.
However, don’t expect aspirin to protect your cardiovascular health single-handedly. It should be only one part of a coordinated effort that includes heart-healthy eating, maintaining a healthy weight, being physically active, keeping your blood glucose controlled, and not smoking. If, in spite of lifestyle measures, you have high blood pressure, high triglycerides, or high LDL cholesterol and low HDL cholesterol, taking appropriate medicines for these conditions will likely be a part of your heart attack and stroke prevention plan, as well.
The recommendations for who should take aspirin to reduce the risk of cardiovascular “events” has not changed; it just seems the evidence to support aspirin use in people who do not have cardiovascular disease is not as strong as once thought. For people who do have cardiovascular disease, aspirin can be beneficial in preventing heart attack.
Even though aspirin is readily available over the counter and is relatively low in cost, it’s a powerful medicine. Be sure to review aspirin use with your diabetes care provider to be sure of the recommendation that is right for you.