Reassessing Ferritin Levels in Healthy Older Adults: Updated Reference Ranges and Associated Health Outcomes

Context.—: Ferritin is used as a biomarker for iron storage, but levels vary significantly among individuals. Objective.—: To define a ferritin reference range in older adults and explore its associations with health outcomes. Design.—: A post hoc analysis included 5247 men and 6075 women aged 70 years or older from the Aspirin in Reducing Events in the Elderly trial. At enrollment, participants had no diagnosed cardiovascular disease (CVD), dementia, physical disability, or life-threatening illness. Longitudinal data on mortality, CVD morbidity, and serious hemorrhage were linked to baseline ferritin levels. Ferritin levels were analyzed in quintiles (Q) (Q1-Q5), with Q2 through Q4 as the reference category. Results.—: Median ferritin concentrations were 190 μg/L for men and 125 μg/L for women, measured with the Abbott Alinity platform. Sex-specific reference ranges derived using the Clinical and Laboratory Standards Institute guidelines were 23 to 741 μg/L and 19 to 440 μg/L (2.5th-97.5th percentiles), respectively. No relationship was found between ferritin levels and disability-free survival, mortality, or CVD outcomes. However, men with the lowest ferritin levels had increased future incidence of major hemorrhage (hazard ratio [HR], 1.51; 95% CI, 1.10-2.07), gastrointestinal (GI) bleeding (HR, 2.03; 95% CI, 1.12-3.60), and GI cancer (HR, 1.27; 95% CI, 1.04-1.54). Conclusions.—: A suggested reference range for ferritin in older adults using the Abbott Alinity platform is 25 to 740 μg/L for men and 20 to 440 μg/L for women. Low ferritin levels were associated with increased risks of GI bleeding and GI cancer in older men.