Increased anaemia risk with low-dose aspirin in older adults

The use of low-dose aspirin was associated with a 20% increased incidence of anaemia and decline in ferritin, or blood iron levels, in otherwise healthy older adults, according to new research.

The study, published in Annals of Internal Medicine, was an analysis of the ASPREE (ASPirin in Reducing Events in the Elderly) trial found that suggested that periodic monitoring of haemoglobin should be considered in older patients taking aspirin.

Researchers from Monash University, Melbourne conducted a post-hoc analysis of the ASPREE randomised controlled trial. The trial included 19,114 persons aged 70 years or older who were randomly assigned to take 100mg of aspirin daily or placebo. Haemoglobin was measured annually, and ferritin was measured at baseline and 3 years after randomisation.

Increased risk for major bleeding with low-dose aspirin

The data showed that the risk for developing anaemia was 23.5% among those assigned to receive low-dose aspirin. These results were accompanied by a small but greater decrease in mean haemoglobin and a greater decline in ferritin concentrations among those receiving aspirin.

Differences in clinically significant bleeding events did not account for the overall difference in incident anaemia or the decline in ferritin observed in ASPREE but was most likely due to occult blood loss given the observed steeper decline in ferritin in participants allocated to aspirin.

The aim of the study was to investigate the effect of low dose aspirin on iron deficiency and anaemia as approximately half of older persons in the US have reported preventative aspirin use. One of the complications of aspirin use is an increased risk for major bleeding, particularly gastrointestinal bleeding. Although the risk for overt bleeding due to aspirin has been well characterised, very few studies have measured the effect of aspirin on anemia, particularly in older populations.