Introduction: Accelerated cognitive decline is influenced by vascular aging. Arterial stiffness and pressure amplification, measures of vascular aging, are associated with lower cognitive performance though their association with cognitive domains has been understudied.
Hypothesis: Arterial stiffness and pressure amplification are associated with lower global and domain-specific cognition among a sample of Caucasian and African American (AA) older adults.
Methods: In a cross-sectional study of 4618 members from visit 5 (2011-2013) of ARIC (mean age: 75 years, 41% men, 20% AA), we measured arterial stiffness (carotid-femoral pulse wave velocity (cfPWV)) and pressure amplification (pulse pressure amplification (PPA), central pulse pressure (cPP) and carotid systolic blood pressure (cSBP)) using the Omron VP-1000 Plus device. Race-specific 25th percentile cut points were estimated for each measure. Domain-specific cognitive function was examined using the Delayed Word Recall Test (memory), Digit Symbol Substitution Test (executive function/processing speed), and Word Fluency Test (language). Test-specific z scores were calculated from sample means and standard deviations. A global cognition z score was generated by averaging the test-specific z scores. Linear regression was used to estimate the associations between race-specific 25th percentile dichotomies for arterial stiffness and pressure amplification measures with test-specific and global cognition z scores, adjusted for age, sex, education, ApoE4, heart rate, smoking and body mass index.
Results: Among AAs, there was no significant association between measures of arterial stiffness and pressure amplification with either global or the domain-specific measures of cognition. Among Caucasians, all measures of arterial stiffness and pressure amplification were associated with lower global cognitive z scores (cfPWV: Beta (β) =-0.11, 95% Confidence Interval (CI): -0.19, -0.04; PPA: β=-0.11, 95% CI: -0.19, -0.03; cPP: β=-0.11, 95% CI: -0.18, -0.04; cSBP: β=-0.12, 95% CI: -0.20, -0.05). All measures of arterial stiffness and pressure amplification also were associated with lower executive function/processing speed (cfPWV: β=-0.09, 95% CI: -0.16, -0.03; PPA: β=-0.15, 95% CI: -0.22, -0.08; cPP: β=-0.14, 95% CI: -0.21, -0.07; cSBP: β=-0.13, 95% CI: -0.20, -0.07). High cfPWV was associated with lower memory (β=-0.12, 95% CI: -0.20, -0.04); and high cSBP was associated with lower language (β=-0.12, 95% CI: -0.20, -0.04).
Conclusions: Arterial stiffness and measures of pressure amplification are inversely associated with global and domain-specific cognition in Caucasian older adults, but not in a smaller sample of AAs. Further study of the role of modifiable components of arterial aging on the preservation of cognition, particularly executive function/psychomotor speed, in older adulthood is warranted.