PULSE PRESSURE IN LATE-LIFE AND ALZHEIMER’S AND CEREBROVASCULAR NEUROPATHOLOGY

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Pulse pressure (PP), the difference between systolic (SBP) and diastolic blood pressure (DBP), is a marker of vascular aging previously associated with brain atrophy, Alzheimer's disease (AD) dementia, and cerebrovascular neuropathology (CVNP) in older adults. Increased PP may be associated with CVNP, in turn lowering the threshold for those with AD neuropathology (ADNP) to be diagnosed with AD dementia. Initial studies suggest that increased PP may be associated with AD pathogenesis. Additional studies are needed to investigate the association of PP with ADNP and CVNP. We used data on non-demented and demented ≥60 year olds in the National Alzheimer's Coordinating Center's Uniform Data Set. Brachial PP was calculated by subtracting DBP from SBP. ADNP was defined as having moderate/frequent neuritic plaques and Braak stage III-VI, and a CVNP index was based on the presence/absence of five cerebrovascular neuropathologies (low CVNP: score≤3; high CVNP: score>3). Multivariable logistic regression was used to examine if baseline PP or annual PP change was associated with ADNP or CVNP. Covariates included demographics, time between baseline and death, apolipoprotein E genotype, and antihypertensive medication use. Interaction terms between baseline PP and APOE e4 genotype were tested in models focused on associations with baseline PP. The 696 non-demented (ADNP: 39%; CVNP: 46%) and 1,481 demented participants (ADNP: 72%; CVNP: 39%) were a mean age of 79 years, 54% were male, 45% were APOE e4 carriers, and 58% took antihypertensives. High PP (>63mmHg) was present in 45% of non-demented and 34% of demented participants, respectively, and 76% of those with high PP had high SBP (≥140mmHg). Baseline PP and annual PP change were not associated with ADNP or CVNP, nor was APOE e4 genotype an effect modifier of the associations with baseline PP. Antihypertensive use was associated with lower odds of ADNP in non-demented participants (OR: 0.91, 95% CI: 0.83–1.00), and a higher odds of CVNP in non-demented (OR: 1.06, 95% CI: 1.00–1.12) and demented participants (OR: 1.08, 95% CI: 1.02–1.14). Baseline PP and annual change in PP were not associated with ADNP or CVNP; however, antihypertensive use was associated with both.