Late-Life Blood Pressure Associated With Alzheimer Disease Brain Pathology
Patients with a higher mean systolic blood pressure during follow-up had increased odds for brain infarcts compared with those with lower levels.
A faster decline in systolic blood pressure among older adults as well as a high average late-life systolic and diastolic blood pressure are associated with an increased risk for future brain infarcts, according to a study published in Neurology.
Detailed neuropathologic data were collected from a total of 1288 community-dwelling older adults during autopsy (mean age at death, 88.6 years; 65% women). Prior to autopsy, participants had systolic and diastolic blood pressure measurements recorded on an annual basis. In regression analyses, the researchers investigated associations between neuropathology with average and declines in late-life systolic and diastolic blood pressures.
During the mean follow-up of 8 years, the average standardized person-specific systolic blood pressure and diastolic blood pressure was 134 mmHg (standard deviation [SD]=13) and 71 mmHg (SD=8), respectively. Patients with a higher mean systolic blood pressure during this period had an increased odds for brain infarcts compared with those with lower levels. For each 1 SD increase in the mean systolic blood pressure, the investigators found a 46% increase in the odds of a patient having ≥1 infarct and a 36% increased odds of a patient having a microinfarct. A rapidly declining systolic blood pressure slope also increased the risk for ≥1 infarct.
Although there was no association between the systolic blood pressure slope and arteriolosclerosis (P =.900), the investigators observed a significant association between the mean systolic blood pressure and arteriolosclerosis (odds ratio [OR] 1.23; 95% CI, 1.05-1.43). Additionally, an association was found between the mean systolic blood pressure and higher atherosclerosis severity grades (OR 1.95; 95% CI, 1.66-2.29).
The mean diastolic blood pressure (OR 1.36; 95% CI, 1.16-1.59) as well as the declining slope of diastolic blood pressure (OR 1.43; 95% CI, 1.10-1.84) were also associated with higher severity grades of atherosclerosis. Finally, patients with a higher mean systolic blood pressure also had significantly higher tangle pathology levels (estimate = 0.168, SD=0.078; P =.031).
Limitations of the analysis include the lack of access to midlife blood pressure data as well as the inclusion of patients with mostly well controlled blood pressure, resulting in findings with limited generalizability.
Findings from the study indicate “that average blood pressure, and especially systolic blood pressure, may remain an important determinant of cerebrovascular disease in late life.”
Arvanitakis Z, Capuano AW, Lamar M, et al. Late-life blood pressure association with cerebrovascular and Alzheimer disease pathology. Neurology. 2018;91:e517-e525.