Cerebrovascular reactivity and midlife cognitive decline, a longitudinal sub-study of the Coronary Artery Risk Development in Young Adults (CARDIA) cohort

Reduced cerebrovascular reactivity(CVR), a measure of metabolic changes in response to a vasoactive stimulus, has been implicated in cognitive decline. Changes in CVR in mid-life may be an early marker of later cognitive problems. Extant studies are small, mainly cross-sectional and are performed in elderly populations. Five-year change in CVR and cognition was studied in 454 participants of the brain MRI sub-study of the longitudinal bi-racial community-based CARDIA cohort. CVR was measured in mean % change in Blood-Oxygen-Level-Dependent (BOLD)-signal over 4 successive breath-hold challenges during fMRI. Cognition was measured with the Digit-Symbol-Substitution-Test(DSST). We used linear regression to examine change in DSST score in relation to change CVR in the total brain and by gray and white matter of the 4 lobes, adjusting for age, gender, race and the 3 field centers. Participants had a mean age of 50y(SD 3.5) at baseline. CVR in the total brain declined by 0.01 % change in BOLD-signal(SD 0.59), p=0.86, and DSST score by 1.68 points(SD 8.7), P