A new study associates the daily use of low-dose aspirin with a higher risk of developing anemia in adults 65 years and older.
Anemia is the most common blood disorder affecting over three million Americans. It occurs when a person does not have enough red blood cells or when they do not function properly. The condition is diagnosed by measuring levels of hemoglobin, a protein in red blood cells that carries oxygen to the body’s organs and tissues, and ferritin, an iron-containing blood protein.
People over the age of 65 are at increased risk of developing anemia, which may be related to diet or chronic health conditions.
The researchers from Monash University in Australia examined how prolonged low-dose aspirin use affects iron deficiency and anemia. The study, published in Annals of Internal Medicine, followed 19,114 initially healthy adults 65 years and older in the United States and Australia for about five years.
The participants were randomized into groups taking 100mg of aspirin or placebo daily. Each year, hemoglobin concentration was measured in all participants, whereas ferritin tests — a test that measures the protein that stores iron — were done in 7,139 of the participants at the beginning of the study and three years later.
The risk of developing anemia was found to be 20% higher in the aspirin group compared to those in the placebo group. In addition, aspirin users experienced a faster decline in hemoglobin and reduced ferritin levels than those taking the placebo.
"This study gives a clearer picture of the additional risk of becoming anemic with aspirin use and the impact is likely to be greater in older adults with underlying diseases, such as kidney disease," says lead author, Associate Professor Zoe McQuilten from Monash University’s School of Public Health and Preventive Medicine.
The study’s limitations include the lack of available data on the causes of anemia. Moreover, it remains unclear if anemia associated with aspirin use produced symptoms impairing the quality of life.
Aspirin is a common medication used to thin the blood to prevent blood clots, but it is linked to an increased risk of bleeding in some patients. Since 2018, the American Heart Association and American College of Cardiology no longer recommend aspirin for cardiovascular disease prevention in adults aged 70 and older.
Although further research is necessary on the link between daily aspirin use and anemia, the authors suggest considering periodic hemoglobin monitoring in older individuals on aspirin.
- Annals of Internal Medicine. Effect of Low-Dose Aspirin Versus Placebo on Incidence of Anemia in the Elderly.
- Monash University. Low-dose aspirin may increase anaemia risk in healthy older adults: study.
- American Society of Hematology. Anemia.
- National Institutes of Health. Aspirin use may be widespread despite new guidelines.