August 26, 2014Open Access
View Full PaperLong-Term Blood Pressure Variability Throughout Young Adulthood and Cognitive Function in Midlife
Key Result
Higher long-term blood pressure variability over 25 years was significantly associated with lower scores on midlife psychomotor speed (P<0.001) and verbal memory tests (P<0.05).
Study Design
Type
Cohort (n=2,326)
Structured PICO
Does higher long-term blood pressure variability from young adulthood to midlife reduce cognitive function in midlife?
P
Population
2,326 healthy young adults (mean age 25 years, 57% female) followed for 25 years to assess the association between blood pressure variability and midlife cognitive function.
E
Exposure
Higher long-term blood pressure variability (assessed by standard deviation [SD] and average real variability [ARV]) over 25 years
C
Comparator
Lower long-term blood pressure variability
O
Outcome
Cognitive function assessed by the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and modified Stroop test at 25-year follow-upsurrogate
Long-term blood pressure variability from young adulthood to midlife is independently associated with worse psychomotor speed and verbal memory, suggesting BP variability is a risk factor for cognitive decline.
Main Result
Effect estimate: β -0.025
p-value: p=<0.001
Abstract
Whether long-term blood pressure (BP) variability throughout young adulthood is associated with cognitive function in midlife remains uncertain. Using data from the Coronary Artery Risk Development in Young Adults (CARDIA), which recruited healthy young adults aged 18 to 30 years (mean age, 25 years) at baseline (Y(0)), we assessed BP variability by SD and average real variability (ARV) for 25 years (8 visits). Cognitive function was assessed with the Digit Symbol Substitution Test (psychomotor speed test), the Rey Auditory Verbal Learning Test (verbal memory test), and the modified Stroop test (executive function test) at follow-up (Y(25)). At the Y(25) examination, participants (n=2326) had a mean age of 50.4 years, 43% were men, and 40% were black. In multivariable-adjusted linear regression models, higher ARV(SBP), ARV(DBP), and SD(DBP) were significantly associated with lower scores of Digit Symbol Substitution Test (β SE: -0.025 0.006, -0.029 0.007, and -0.029 0.007, respectively; all P<0.001) and Rey Auditory Verbal Learning Test (β SE: -0.016 0.006, -0.021 0.007, and -0.019 0.007, respectively; all P<0.05) after adjustment for demographic and clinical characteristics and with cumulative exposure to BP through Y(0) to Y(25). Neither SDBP nor ARV(BP) was associated with the Stroop score. The associations between ARV(BP) or SD(BP) and each cognitive function test were similar between blacks and whites except for 1 significant interaction between race and SDS(BP) on the Digit Symbol Substitution Test (P<0.05). Long-term BP variability for 25 years beginning in young adulthood was associated with worse psychomotor speed and verbal memory tests in midlife, independent of cumulative exposure to BP during follow-up.