Rabin JS, et al. - In this longitudinal observational study, researchers ascertained if vascular risk and Aβ burden act additively or synergistically to promote cognitive decline in clinically normal older adults as well as assessed the unique influence of vascular risk on prospective cognitive decline beyond that of commonly used imaging biomarkers, including Aβ burden, hippocampal volume, fludeoxyglucose F18–labeled (FDG) positron emission tomography (PET), and white matter hyperintensities, a marker of cerebrovascular disease. Findings suggested an association of vascular risk with a prospective cognitive decline in clinically normal older adults, both alone and synergistically with Aβ burden. In older adults with preclinical Alzheimer disease, the vascular risk might complement other imaging biomarkers in evaluating the risk of cognitive decline.

Methods

• From the Harvard Aging Brain Study, researchers analyzed clinically normal older adults.
• Study participants in this analysis were required to have baseline imaging data (FDG-PET, Aβ-PET, and magnetic resonance imaging), baseline medical data to quantify vascular risk, and at least 1 follow-up neuropsychological visit.
• Data collection started in 2010 and is continuous.
• They performed data analysis on data collected between 2010 and 2017.
• Using the Framingham Heart Study general cardiovascular disease (FHS-CVD) risk score, vascular risk was quantified.
• After that, Aβ burden with Pittsburgh Compound-B PET was measured.
• With the Preclinical Alzheimer Cognitive Composite, cognition was measured annually.
• They corrected models for baseline age, sex, years of education, and apolipoprotein E ε4 status.

Results

• As per data, out of 223 study participants, 130 (58.3%) were women.
• It was noted that the mean (SD) age was 73.7 (6.0) years, and the mean (SD) follow-up time was 3.7 (1.2) years.
• They observed that faster cognitive decline was related to both a higher FHS-CVD risk score (β = -0.064; 95% CI, -0.094 to -0.033; P < .001) and higher Aβ burden (β = -0.058; 95% CI, -0.079 to -0.037; P < .001).
• The interaction of the FHS-CVD risk score and Aβ burden with time was significant (β = -0.040, 95% CI, -0.062 to -0.018; P < .001), recommending a synergistic effect.
• Findings revealed that the FHS-CVD risk score remained robustly related to prospective cognitive decline (β = -0.055; 95% CI, -0.086 to -0.024; P < .001), even after adjustment for Aβ burden, hippocampal volume, FDG-PET uptake, and white matter hyperintensities.