Alzheimer's Imaging Consortium

Area of Science:

• Neuroscience
• Gerontology
• Public Health

Background:

• Chronic stress accelerates biological aging, particularly in marginalized populations, increasing Alzheimer's disease and related dementias (AD/ADRD) risk.
• Midlife brain aging involves structural changes like white matter hyperintensity (WMH) volume and reduced cortical thickness (CT).
• Understanding the link between biological aging, brain markers, and social determinants is crucial for addressing health disparities.

Purpose of the Study:

• To investigate the association between biological age acceleration (GrimAge) and ADRD-related MRI markers (WMH volume, CT).
• To examine these associations in a racially/ethnically diverse midlife cohort.
• To explore the moderating effects of education and cardiovascular disease (CVD) burden.

Main Methods:

• Examined 681 diverse adults (45-65 years) from the Offspring Study of Racial and Ethnic Disparities in Alzheimer's Disease.
• Used linear regression to assess relationships between biological age acceleration and MRI outcomes, adjusting for covariates.
• Conducted stratified analyses by race/ethnicity and tested for interactions with education and CVD burden.

Main Results:

• Accelerated biological aging correlated with increased WMH volume (β=0.014), but not CT.
• The association between biological age and WMH was amplified by greater CVD burden (β=0.028).
• Higher education and White, Latinx participants showed less biological age acceleration; associations were strongest in Black and Latinx individuals.

Conclusions:

• Accelerated biological aging is linked to increased WMH volume, potentially contributing to brain health disparities.
• Cardiovascular burden exacerbates the association between accelerated aging and WMH.
• Multifaceted interventions addressing sociocultural and biological factors are needed to reduce brain health disparities.