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In older adults, anemia may increase with use

June 20, 2023 – Older individuals who take low-dose aspirin day by day have a 20% higher risk of Development of anemiashow latest research results.

The study, published Monday within the Annals of Internal Medicineexamined hemoglobin concentrations in greater than 19,000 healthy adults within the United States and Australia who were 65 years of age and older.

Low levels of hemoglobin, an iron-containing protein in red blood cells that carries oxygen throughout the body, can result in anemiawhich is common in older people and may cause fatigue, rapid or irregular heartbeat, headaches, chest pain and throbbing or whooshing noises within the ears. In people over 65, it could also result in a worsening of conditions similar to heart failure, cognitive impairment and depression.

“We knew from large clinical trials, including our … study, that taking low-dose aspirin daily increased the risk of clinically significant bleeding,” said Zoe McQuilten, MBBS, PhD, a hematologist at Monash University in Australia and lead creator of the study. “From our study, we found that taking low-dose aspirin during the study also increased the risk of anemia, and this was most likely due to bleeding that was not clinically apparent.”

The US Preventive Services Task Force changed its recommendation on aspirin as primary prevention of heart problems in 2022 and advises against starting low-dose aspirin in adults aged 60 and older. For adults aged 40 to 59 with a 10-year heart problems risk of 10% or more, the agency recommends that patients and health care providers make the choice to take low-dose aspirin on a case-by-case basis because the general profit is small.

McQuilten said that in lots of cases of anemia, doctors cannot find the cause. A study published within the Journal of the American Geriatrics Society In 2021, it was found that a few third of anemia cases had no clear cause.

About 50% of individuals involved in probably the most recent study took aspirin for prevention from 2011 to 2018. That number has likely dropped after guidelines changes in 2022, in line with McQuilten, but can have persevered long-term in older patients. The researchers also checked out ferritin levels, which serves as an indicator of iron levels (and may indicate anemia when low), initially of the study and again after 3 years.

People who took aspirin were more prone to have lower serum ferritin levels after three years than those that took a placebo. The average decline in ferritin amongst people within the study who took aspirin was 11.5% greater than amongst those that took a placebo.

The estimated risk of anemia inside 5 years was 23.5% within the aspirin group and 20.3% within the placebo group. Overall, aspirin therapy resulted in a 20% increased risk of anemia.

Basil Eldadah, MD, PhD, chief medical officer on the U.S. National Institute on Aging, said the findings should encourage health care providers to discuss with their patients in regards to the have to take aspirin.

“For someone who is taking aspirin and is older and whose indication is not cardiovascular disease, you should seriously consider whether that is the best treatment option,” said Eldadah, who was not involved within the study.

The study didn’t examine the results of the anemia on participants. This could possibly be the topic of future research, he said. One limitation, the researchers said, is that it isn’t clear whether the anemia was enough to cause symptoms that affected the study participants' quality of life or whether unknown bleeding caused the anemia.

The researchers also didn’t document whether the patients visited their regular doctors and received treatment for anemia throughout the study.