Sex moderates the relationship between aortic stiffness, cognition and cerebrovascular reactivity in healthy older adults
It is well established that sex differences exist in the manifestation of cardiovascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. We investigated the possible role of sex and hematocrit (HCT) on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Dual-echo pCASL data were collected during a hypercapnia challenge. Aortic PWV data was acquired using cine phase contrast velocity series. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF. In addition, there was a significant effect of HCT on the sex differences observed in the moderation effect on EF. Together, our results indicate that the relationships between PWV, CVR and EF are in part mediated by sex and HCT. HighlightsO_LIThis study investigates the role of sex on cerebrovascular measures of brain health and congition C_LIO_LISex moderates the relationship between PWV, cerebrovascular reactivity and cognition C_LIO_LIHematocrit influences the sex differences observed C_LI