Article Impact Level: HIGH Data Quality: STRONG Summary of Annals of Internal Medicine, M23-0675. https://doi.org/10.7326/M23-0675 Dr. Zoe K. McQuilten et al.
Points
- Low-dose aspirin use in older adults increased the incidence of anemia, with 51.2 events per 1000 person-years compared to 42.9 events in the placebo group.
- Hemoglobin concentrations declined more rapidly in the aspirin group, with a decline of 4.2 g/L per 5 years compared to 3.6 g/L in the placebo group.
- In participants with ferritin measurements, the aspirin group had a higher prevalence of ferritin levels below 45 µg/L at year 3 (13% vs. 9.8% in placebo) and a more significant overall decline in ferritin levels by 11.5%.
- The findings were consistent even after accounting for major bleeding events, suggesting that the effects of aspirin on anemia and ferritin decline were independent of bleeding.
- Periodic monitoring of hemoglobin levels should be considered in older individuals taking aspirin to manage and detect anemia.
Summary
This research paper presents a post hoc analysis of the ASPREE (ASPirin in Reducing Events in the Elderly) randomized controlled trial, which included a total of 19,114 community-dwelling persons aged 70 years or older (≥65 years for Black persons and Hispanic persons) in Australia and the United States. The participants were randomly assigned to receive 100 mg of aspirin daily or a placebo. The analysis aimed to investigate the effect of low-dose aspirin on incident anemia, hemoglobin concentrations, and serum ferritin levels.
The study results showed that the incidence of anemia was higher in the aspirin group compared to the placebo group, with 51.2 events and 42.9 events per 1000 person-years, respectively (hazard ratio, 1.20 [95% CI, 1.12 to 1.29]). Hemoglobin concentrations declined over time in both groups, but the aspirin group experienced a steeper decline. Specifically, the hemoglobin concentrations decreased by 3.6 g/L per 5 years in the placebo group, whereas the aspirin group had a decline of 4.2 g/L per 5 years (95% CI, 0.3 to 1.0 g/L).
Moreover, in a subset of 7,139 participants who had ferritin measurements at baseline and after three years, the aspirin group had a higher prevalence of ferritin levels below 45 µg/L at year 3 (13% vs. 9.8% in the placebo group) and a more significant overall decline in ferritin levels by 11.5% (95% CI, 9.3% to 13.7%) compared with placebo. Notably, a sensitivity analysis that excluded the effect of significant bleeding yielded similar results, indicating that the observed outcomes were independent of bleeding events.
In conclusion, this analysis of the ASPREE trial revealed that daily low-dose aspirin use in older adults increased the incidence of anemia and led to a steeper decline in hemoglobin concentrations compared to placebo. Furthermore, the aspirin group had a higher prevalence of low ferritin levels and experienced a more significant decline over time. These findings highlight the importance of periodic monitoring of hemoglobin levels in older individuals taking aspirin, even without significant bleeding. However, it is essential to note that this analysis had certain limitations, such as annual hemoglobin measurements and a lack of data on the specific causes of anemia.
Link to the article: https://www.acpjournals.org/doi/10.7326/M23-0675
References McQuilten, Z. K., Thao, L. T. P., Pasricha, S.-R., Artz, A. S., Bailey, M., Chan, A. T., Cohen, H. J., Lockery, J. E., Murray, A. M., Nelson, M. R., Schneider, H. G., Wolfe, R., Woods, R. L., Wood, E. M., & McNeil, J. J. (2023). Effect of Low-Dose Aspirin Versus Placebo on Incidence of Anemia in the Elderly: A Secondary Analysis of the Aspirin in Reducing Events in the Elderly Trial. Annals of Internal Medicine, M23-0675. https://doi.org/10.7326/M23-0675
