Low-dose aspirin may increase anemia risk in healthy older adults: study
A new study analysing data from the landmark ASPREE trial has found that prolonged daily aspirin use increases the risk of anemia by 20% in some older adults, mostly aged over 70 years (65 years for African Americans and Hispanic individuals).
The results may help physicians identify older patients at higher risk of anemia and who may benefit from regular monitoring.
This Australian and US study, published in Annals of Internal Medicine, followed 18,153 initially healthy older adults in the USA and Australia and recorded incidents of anemia over an average 4.7 years.
The risk of developing anemia was found to be 20 per cent higher in the aspirin group compared to those in the placebo group.
This is the largest investigation into anemia in older people and was a part of the randomised controlled trial, ASPREE (ASPirin in Reducing Events in the Elderly) – with half the participants taking a placebo and the other half a daily low dose (100mg) of aspirin.
Anemia is commonly experienced by older adults, potentially affecting overall function and increasing fatigue, disabilities, depressive symptoms and problems with thinking and memory. Around one third of all cases of anemia in older adults have no known cause.
Over the duration of the trial, 18% of participants in the aspirin group and 15% in the placebo group developed anemia.
In addition to a higher risk of anemia, blood tests revealed a faster decline of hemoglobin (a protein that carries oxygen in our red blood cells) and reduced ferritin (a protein that carries iron) levels in the aspirin group compared to the placebo group.
Lead author, Associate Professor Zoe McQuilten from Monash University’s School of Public Health and Preventive Medicine, said while bleeding was a known side-effect of aspirin, few previous studies had looked at the effect of prolonged aspirin use on the progressive development of anemia in older adults.
“This study gives a clearer picture of the additional risk of becoming anaemic with aspirin use and the impact is likely to be greater in older adults with underlying diseases, such as kidney disease,” A/Prof McQuilten said.
A/Prof McQuilten said the new data gave doctors insight into the risk of anemia from prolonged aspirin use by their older patients. “Older adults are more likely to become anaemic generally and now doctors can potentially identify patients at higher risk of developing anemia,” she said.
Principal Investigator to the ASPREE Project in the US, Dr Anne Murray, urged patients to follow the advice of their doctor about their daily use of aspirin. She cautioned that for some older adults that have had previous heart attacks, strokes, or have atrial fibrillation, aspirin may be recommended as a valuable therapy to prevent recurring heart attacks or stroke. However, aspirin is not recommended for primary prevention: e.g. to prevent a first heart attack or stroke in those 60 years and older, unless per their doctor’s evaluation there are other factors that places them at increased risk . “Patients should not change their aspirin regimen without speaking to their doctor,” said Prof Murray.
“Physicians are experienced at investigating and managing anemia and low iron levels.”