BACKGROUND AND PURPOSE:

McQuilten et al. (Ann Intern Med, 2023) investigated the effect of low-dose aspirin on incident anemia, hemoglobin, and serum ferritin concentrations.

METHODS:

• Post hoc analysis of an RCT
  • ASPREE (ASPirin in Reducing Events in the Elderly) trial
• Participants
  • Community-dwelling ≥70 years or ≥65 years for Black and Hispanic persons
• Intervention
  • 100 mg of aspirin daily
  • Placebo
• Primary outcomes
  • Anemia incidence
  • Hemoglobin concentrations (measured annually)
  • Ferritin concentrations (measured at 3 years after assignment)

RESULTS:

• 19,114 individuals
• Anemia incidence was higher in the aspirin group
  • Placebo: 42.9 events per 1000 person-years | Aspirin: 51.2 events
  • Hazard ratio (HR) 1.20 (95% CI, 1.12 to 1.29)
• Both groups experienced declines in hemoglobin concentrations with steeper decline in the aspirin group
  • Placebo: 3.6 g/L per 5 years
  • Aspirin: 0.6 (95% CI, 0.3 to 1.0) g/L per 5 years
• Subgroup analysis: Aspirin group had
  • Greater prevalence of ferritin levels <45 µg/L at year 3
    • Placebo: 9.8% | Aspirin: 13%
  • Greater overall decline in ferritin
    • Aspirin: 11.5% (95% CI, 9.3 to 13.7)
• Similar results found in the absence of major bleeding

CONCLUSION:

• Even in the absence of major bleeding, daily aspirin led to increased incidence of anemia and reduced ferritin levels in healthy older adults
• The authors state

Low-dose aspirin increased incident anemia and decline in ferritin in otherwise healthy older adults, independent of major bleeding

Periodic monitoring of hemoglobin should be considered in older persons on aspirin 

Learn More – Primary Sources:

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