Supplementary results for: Visit-to-visit blood pressure variability, neuropathology and cognitive function

Objective Large systolic blood pressure (SBP) variability has been
proposed as a novel risk factor for dementia above and beyond SBP levels,
but the underlying neuropathology is largely unknown. We investigated the
relationship among visit-to-visit SBP variability, cognitive deterioration
and underlying neuropathological changes. Methods We used longitudinal
data (between 2005 and 2019) from the National Alzheimer’s Coordinating
Center. 13,284 dementia-free participants aged≥50 years were followed over
a median of 5.0 (interquartile range: 3.1-7.6) years. Neuropathology data
were available in 1,400 autopsied participants. Visit-to-visit SBP
variability was quantified from repeated annual SBP measurements.
Cognitive deterioration was defined as conversion from normal cognition to
mild cognitive impairment (MCI) or dementia, or from MCI to dementia.
Results Larger visit-to-visit SBP variability was associated with
cognitive deterioration (adjusted odds ratio comparing extreme quintiles:
2.64; 95%CI:2.29-3.04, P <0.001). It was also associated with a
higher burden of vascular pathology (including microinfarcts, white matter
lesion, atherosclerosis of the circle of Willis and arteriolosclerosis)
and with neurofibrillary tangle pathology assessed by Braak staging (All P
< 0.05). The association with cognitive deterioration and vascular
pathology appeared stronger among those with normal cognition versus MCI
at baseline. These findings were observed after adjusting for age, sex,
mean SBP and other confounding variables. Similar results were observed
for diastolic BP variability. Conclusion Larger visit-to-visit SBP
variability was associated with cognitive deterioration. It was also
associated with cerebrovascular pathology and neurofibrillary tangles.
These results suggest the intertwined role of vascular and
Alzheimer's disease pathology in the etiology of dementia.