Anemia Associated with Increased Dementia Risk and Alzheimer Biomarkers
Overview
A cohort study of older adults found that anemia is linked to a 66% higher risk of developing dementia and elevated Alzheimer disease–related blood biomarkers. The highest dementia risk was observed when anemia co-occurred with elevated neurodegenerative markers, particularly neurofilament light chain (NfL).
Background
Dementia is a major neurodegenerative condition with complex risk factors. Anemia, characterized by low hemoglobin levels, may influence brain health and resilience. Alzheimer disease biomarkers such as phosphorylated tau 217 (p-tau217), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) reflect underlying neuropathology and neurodegeneration. Understanding the relationship between anemia and these biomarkers can elucidate mechanisms contributing to dementia development.
Data Highlights
Parameter
Finding
Sample size
2,282 dementia-free adults aged ≥60 years
Follow-up duration
Mean 9.3 years
Dementia cases
362 participants developed dementia
Increased dementia hazard with anemia
66% higher compared to normal hemoglobin
Biomarkers elevated with anemia
p-tau217, NfL, GFAP (largest increases in NfL and p-tau217)
Dementia risk with anemia + high NfL
Nearly 4-fold higher hazard
Key Findings
Anemia was associated with significantly higher baseline levels of Alzheimer disease–related biomarkers p-tau217, NfL, and GFAP.
Participants with anemia had a 66% increased hazard of developing dementia compared to those with normal hemoglobin.
Dementia risk was highest when anemia coexisted with elevated NfL, showing nearly a fourfold increase in hazard.
Sex differences were noted: associations were stronger in men, possibly due to women's greater tolerance to lower hemoglobin levels.
APOE epsilon 4 status modified the relationship between anemia, biomarkers, and dementia risk, with different patterns observed in carriers versus noncarriers.
Most anemia cases were normocytic, and biomarker and hemoglobin levels were measured only at baseline, limiting longitudinal assessment.
Clinical Implications
Clinicians should consider anemia as a potential modifiable risk factor for dementia, especially in older adults presenting with elevated Alzheimer disease biomarkers. Monitoring hemoglobin levels alongside neurodegenerative markers may help identify individuals at higher risk. Addressing anemia could contribute to strategies aimed at reducing dementia incidence or delaying its onset.
Conclusion
This study highlights a significant association between anemia and increased dementia risk mediated by Alzheimer disease–related biomarkers, underscoring the importance of integrated assessment of hematologic and neurodegenerative factors in aging populations.
References
Valletta et al. 2024 -- Anemia Tied to Higher Dementia Risk, JAMA Network Open
