Vascular Risk Factors May Increase Dementia Burden in Older Adults

Vascular risk factors contribute to the burden of cognitive impairment and dementia in the United States, according to a scientific statement from the American Heart Association (AHA) published in Stroke.

To estimate the prevalence and incidence of vascular contributions to cognitive impairment and dementia (VCID) in the United States, the AHA reviewed studies involving patients diagnosed with vascular dementia, individuals with evidence of vascular dementia in epidemiological studies, cases with neuropathological evidence of cerebrovascular involvement, and those with neuroimaging findings of covert cerebrovascular disease.

Estimating VCID disease burden is complicated by inconsistent diagnostic criteria and the absence of definitive biomarkers. Assessment typically involves clinical evaluation, neuroimaging, or postmortem analysis, though each method has limitations.

Notably, discrepancies exist between epidemiological studies and billing data. In 2020, using research-based methods, it was estimated that approximately 2.7 million adults aged 65 years and older were living with vascular or mixed dementia, though billing records identified only 809,000 patients. New diagnoses were similarly underreported, with 603,000 incident cases estimated via research data vs 102,000 identified through billing codes.

Subclinical cerebrovascular disease is also widespread. In 2020, neuroimaging findings suggested that 11.3 million older adults had covert brain infarcts, 11.1 million had high white matter hyperintensity volumes, and 19.9 million had cerebral microbleeds. Though often silent, these markers are strongly linked to dementia risk. Autopsy studies further suggest that vascular pathology contributes to 27% to 33% of dementia cases, suggesting that elimination of cerebrovascular disease could have prevented up to 1.8 million dementia cases in 2020.

Disparities in VCID prevalence and incidence were also observed across racial and ethnic groups. Black, Hispanic, American Indian/Alaska Native, and Native Hawaiian populations had higher rates of vascular dementia compared with non-Hispanic White and Asian groups. Differences are largely attributable to modifiable risk factors, including hypertension, diabetes, obesity, and smoking, which together may account for up to 40% of dementia cases. Sex-related patterns have been less consistent, with some studies showing higher incidence in men.

While longitudinal data from population-based cohorts like the Framingham Heart Study suggest a decline in age-adjusted incidence of vascular dementia over time, the overall burden remains high. The AHA underscores the need for standardized diagnostic criteria, validated biomarkers, and greater use of dementia subtyping in research and clinical practice.

“Integrating vascular risk reduction strategies into public health initiatives is essential to safeguarding brain health and reducing the burden of dementia,” the AHA writing group wrote.

Disclosures: This research was supported by the AHA. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.