Daily Aspirin may cause anaemia in elderlies, study says

Aspirin is one of the most commonly used medications. Studies show that more than 40 per cent of adults ages 60 and older take an aspirin every day to prevent dangerous blood clots that could lead to a heart attack or stroke.

Because aspirin can contribute to the danger of big bleeds like aneurysms, researchers wanted to know whether it might also be a factor in more subtle blood loss: the kind that may lead to anaemia, or reduced oxygen in the blood. According to the news release, anaemia is another problem among the elderly, like heart attacks and strokes. Studies show that 30 per cent of adults 75 and older worldwide are anaemic, and anaemia is generally tied to poor health – including fatigue, memory loss and cognitive issues, depression and an increased risk of death.

A recent study published in the Annals of Internal Medicine followed more than 18,000 adults who were 65 and older from the US and Australia. Half took 100 milligrams of aspirin a day – a low dose – while the other half took a dummy pill. The researchers followed them for about five years. Study participants had yearly doctor’s visits and blood tests for haemoglobin and ferritin, a protein in blood cells that stores iron.

They saw a small but clear difference. Adults who took aspirin were 20 per cent more likely to be anaemic than those who didn’t take it. Based on their results, the researchers estimated that 24 per cent of seniors in the daily aspirin group would develop anaemia within five years, compared with 20 per cent of those in the placebo group. Those on aspirin regimens also had slightly lower levels of haemoglobin and ferritin, which help blood cells to carry oxygen.

The difference remained even when the researchers adjusted their data to account for cancer and for major bleeding events during the study, and for other differences between the participants like age, sex, diabetes, kidney disease and the use of nonsteroidal anti-inflammatory medications, or NSAIDs.

The study did not observe how aspirin may be contributing to anaemia, but the authors have an idea about how it might happen. Aspirin makes it harder for blood to clot because it keeps platelets from sticking together.

The researchers wrote that because they saw this effect across many different groups, regardless of their underlying health, it’s likely to be a bigger concern for people who have other risks for anaemia, such inflammatory diseases like arthritis or chronic renal insufficiency.

They say doctors should consider more closely monitoring their patients’ haemoglobin levels if they have multiple risk factors, including aspirin use.