Hypertension has long been tied to cognitive decline, but new research in JAHA suggests it’s actually hypotension that carries the strongest association with Alzheimer’s disease.
- Traditionally, hypertension negatively impacts cognition by damaging cerebral blood vessels, accelerating brain atrophy, and triggering neuroinflammation.
- However, hypotension can also lead to similar brain impacts by reducing how much blood is delivered to the brain.
To map the relationship between CVD subtypes and Alzheimer’s risk, researchers analyzed EHR data across a UK Biobank and All of Us cohort to examine a wide range of cardiovascular diagnoses and their association with Alzheimer’s using ICD-10 codes.
- Hypotension showed the strongest association with Alzheimer’s in both UK Biobank and All of Us (OR: 2.74 and 1.97, respectively).
- Hypertension ranked second in the UK Biobank (OR: 1.57), followed by cardiac arrhythmias (1.52) and cerebral infarction (1.49).
- In the All of Us cohort, cerebral infarction had the second strongest association (1.85), with hypertension close behind (1.65).
Race and ethnicity also modified the associations in a meaningful way, suggesting the dominant pathway may differ by population.
- Hypotension was most strongly linked to Alzheimer’s in white individuals, while hypertension held the strongest association in Black and Hispanic individuals.
- The researchers attribute this partly to higher rates of uncontrolled hypertension in Black and Hispanic populations.
A genetic proximity analysis added another layer, identifying shared genomic locations between Alzheimer’s disease and CVD-related traits.
- These locations were most prominently near the APOE, MAPT, SPI1, and WNT3 genes.
- APOE stands out given its established roles in lipid metabolism, blood-brain barrier integrity, and both cardiovascular and neurodegenerative disease.
All that said, this hypotension finding warrants careful interpretation. For example, low blood pressure can reflect frailty, heart failure, or prior hypertension treatment, any of which independently elevates dementia risk.
- The study’s cross-sectional design and reliance on ICD-10 coding for hypotension also limit causality conclusions.
The Takeaway
It’s becoming clearer and clearer that heart and brain health are inseparably linked. Although which exact CVD risk factors cause which neurological effects is still being explored, this study makes a strong case for keeping an eye on hypotension.
