December 9, 2023

Long-term use of low-dose aspirin may increase the risk of anemia in healthy older adults, a large new study finds. The researchers say their findings suggest that these patients may require regular monitoring.

Because of its blood-thinning properties, aspirin is often used in low doses to prevent heart attacks or strokes or to prevent the recurrence of these conditions. Although the risk of bleeding from aspirin is well known, few studies have examined the effects of long-term low-dose aspirin use on the risk of anemia in older adults.

Anemia occurs when there are not enough healthy red blood cells. Red blood cells carry oxygen through hemoglobin, an iron-containing protein. A lack of these cells means less oxygen circulates to organs and tissues, which can lead to fatigue, shortness of breath, dizziness or a rapid heartbeat. Anemia can be caused by deficiencies in vitamin B12, folic acid, or iron, as well as chronic diseases such as kidney disease, cancer, or rheumatoid arthritis.

A new study led by researchers at Monash University in Australia analyzed data on ASPirin in reducing incidents in older adults (April) trial, The Long-Term Multicenter Study of Aspirin and Health in older adults, examines how long-term use of low-dose aspirin affects the risk of anemia.

Researchers followed 18,153 initially healthy adults aged 70 or older from Australia and the United States for four and a half years. Half of the participants took low-dose (100 mg) aspirin daily and the other half took a placebo.

They found that the group taking aspirin had a 20 percent higher risk of developing anemia than the placebo group. They also found that hemoglobin levels fell more rapidly in the aspirin group, as did ferritin levels. Ferritin is a blood protein that contains iron. Decreased hemoglobin and ferritin levels were not due to major bleeding.

Zoe McQuilten, lead author of the study, said: “This study provides a clearer picture of the increased risk of anemia associated with aspirin use, and that this effect is greater in people with underlying conditions such as kidney disease. It may be greater in the elderly.”

The researchers say their findings suggest that health professionals may consider more frequent monitoring for symptoms of anemia in healthy older adults taking aspirin.

“Older adults are more likely to develop anemia, and now physicians may be able to identify patients at higher risk for anemia,” McQuilten said.

However, researchers urge people not to stop taking aspirin or change the dose of the drug without first consulting their doctor, especially if they are taking the drug to prevent blood clotting, heart attack or stroke.

The study was published in the journal Annals of Internal Medicine.

source: monash university