An RCT has found that low-dose aspirin use failed to reduce fracture risk but was associated with higher risk of serious falls in the elderly
Daily low-dose aspirin (100 mg) use in healthy elderly patients failed to reduce the risk of fractures but increased the risk of a serious fall according to the findings of a randomised, placebo-controlled trial by Australian researchers.
In a 2017 study it was found that, globally, falls resulted in 695771 deaths and more than 95% of hip fractures are caused by falling. Low-dose aspirin is usually taken by elderly patients with cardiovascular disease although interestingly, there is some evidence to suggest that aspirin inhibits osteoclastogenesis by suppressing the activation of NF‑κB and therefore may possess therapeutic potential for use in the prevention and treatment of osteoporosis. By inhibiting osteoclasts, aspirin may increase bone mineral density and therefore reduce the risk of fractures. In fact, a systematic review of 12 observational studies found that aspirin use was associated with 17% lower odds for any fracture. Nevertheless, to date, no randomised, placebo-controlled trials have examined the potential role of low-dose aspirin as an approach to reduce fracture risk among older adults.
In the present study, the Australian researchers created the ASPREE-FRACTURE study which was actually a sub-study of the ASPirin in Reducing Events in the Elderly trial designed to examine if daily low-dose aspirin use outweigh the risks in older healthy individuals. Participants in the trial received low-dose aspirin (100 mg daily) or matching placebo and the primary outcome was the occurrence of any fracture whereas the secondary outcome was set as a serious fall that resulted in hospital presentation. All participants were free of cardiovascular disease, dementia or physical disability at the start of the study.
Low-dose aspirin and fracture outcomes
A total of 16,703 individuals with a median age of 74 years (55% female) were recruited and randomised to either aspirin (8,322) or placebo and followed-up for a median of 4.6 years.
During follow-up there was no difference in the risk of first (hazard ratio, HR = 0.96, 95% CI -087 – 1.06, p = 0.50) or recurrent (HR = 0.96, 95% CI 0.87 – 1.06, p = 0.40) fracture events. In subgroup analysis based on several factors such as gender, body mass index or frailty, there were no significant differences in the risk of a first fracture event.
However, when researchers looked at the secondary out, 9% of those receiving aspirin compared to 8.2% in the placebo arm, experienced a serious fall, indicating that use of low-dose aspirin used was associated with a significant increase in the risk of such falls (HR = 1.17, 95% CI 1.03 – 1.33, p = 0.01).
The authors concluded that the use of low-dose aspirin provides little favourable benefit in a healthy, older adult population.
Barker AL et al. Daily Low-Dose Aspirin and Risk of Serious Falls and Fractures in Healthy Older People: A Substudy of the ASPREE Randomized Clinical Trial. JAMA Intern Med 2022