5 research outputs found
Arterial stiffness and brain health : investigating the impact of sex-related differences
Introduction: Il est bien eĢtabli que les maladies vasculaires, ceĢreĢbrovasculaires et cardiovasculaires se manifestent diffeĢremment chez les hommes que chez les femmes. La rigiditeĢ arteĢrielle (RA), un preĢdicteur indeĢpendant de la maladie cardiovasculaire (MCV), a eĢteĢ associeĢe aĢ des changements de la reĢactiviteĢ ceĢreĢbrovasculaire (RCV) et aĢ un deĢclin cognitif lors du vieillissement. Plus preĢciseĢment, les personnes aĢgeĢes ayant une RA plus eĢleveĢe preĢsentent un deĢclin plus marqueĢ au niveau des taĢches exeĢcutives. Une diminution des fonctions exeĢcutives (FE) est eĢgalement lieĢe aĢ une reĢduction de la RCV chez les personnes aĢgeĢes. Cependant, il est important de noter que la relation entre la RA et la RCV est plus complexe. Certaines eĢtudes montrent une diminution de la RCV associeĢe avec une RA plus eĢleveĢe, tandis que dāautres rapportent une RCV preĢserveĢe avec une RA eĢleveĢe. De plus, des travaux reĢcents suggeĢrent que les diffeĢrences de concentration en heĢmatocrit (HCT) pourraient avoir une incidence sur les mesures de RA. Ici, nous avons eĢtudieĢ le roĢle possible du sexe et de l'HCT sur ces relations heĢmodynamiques.
MeĢthodes: Des acquisitions ont eĢteĢ effectueĢes chez 48 adultes aĢgeĢs en bonne santeĢ (31 femmes, 63 Ā± 5 ans) dans un scanneur dāimagerie par reĢsonance magneĢtique (IRM) 3T. Des donneĢes de marquage de spin arteĢriel pseudo-continu utilisant des lectures aĢ double eĢcho ont eĢteĢ collecteĢes pendant un deĢfi d'hypercapnie (changement de CO2 de 5mmHg, pendant deux blocs de 2 minutes). La RCV a eĢteĢ calculeĢe comme eĢtant le % de changement du signal de deĢbit sanguin ceĢreĢbral (% āCBF) par changement de mmHg dans le CO2 aĢ la fin de lāexpiration. Les donneĢes de vitesse dāonde de pouls (VOP) aortique ont eĢteĢ acquises aĢ lāaide dāune seĢrie de contraste de phase cine encodeĢe par la vitesse durant 60 phases cardiaques avec un encodage en veĢlociteĢ de 180cm/s dans le plan. La VOP dans l'arcade aortique a eĢteĢ calculeĢe entre l'aorte ascendante et descendante. Les analyses statistiques ont eĢteĢ effectueĢes aĢ l'aide de SPSS.
ReĢsultats: Un test de modeĢration controĢlant pour lāaĢge et le volume des hyperintensiteĢs de la matieĢre blanche a reĢveĢleĢ un effet direct significatif de la VOP sur la RCV (Ī² = 1,630, IC aĢ 95% [.654, 2,607), ainsi que de la VOP sur la FE (Ī² = -. 998, IC 95% [-1,697, -,299]). Le sexe a modeĢreĢ la relation entre VOP et RCV (Ī² = -1,013, IC 95% [-1,610, -,4169]), et VOP et FE (Ī² =
.447, IC 95% [.020, .875]). En outre, il existait un effet significatif de lāHCT sur les diffeĢrences de sexe observeĢes dans lāeffet de modeĢration (VOP * SEXE) sur la FE (Ī² = -0,7680, SE = 0,3639, IC 95% [-1,5047, -0,0314], p = 0,0414).
Conclusion: Nos reĢsultats indiquent que les relations entre la VOP, la RCV et la FE sont complexes et que le sexe et lāHCT modulentces relations. Lāinfluence des variations hormonales (p. ex. la meĢnopause) sur ces relations devrait eĢtre eĢtudieĢe dans le futur et pourrait permettre de personnaliser les strateĢgies de preĢvention des MCV.Introduction: It is well established that sex differences exist in the manifestation of vascular, cerebrovascular and cardiovascular disease. Arterial stiffness (AS), an independent predictor of cardiovascular disease (CVD), has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a steeper decline on executive function (EF) tasks. Decreased EF is also linked with reduction in CVR among older adults. Interestingly, the relationship between AS and CVR is more complex, where some works show decreased CVR with increased AS, and others demonstrate preserved CVR with higher AS. In addition, recent work suggests that measurements of AS may be affected by differences in the concentration of hematocrit (HCT). Here, we investigated the possible role of sex and HCT on these hemodynamic relationships.
Methods: Acquisitions were completed in 48 healthy older adults (31 females, 63 Ā± 5 years) on a 3T MRI. Pseudo-continuous arterial spin labeling using dual-echo readouts were collected during a hypercapnia challenge (5mmHg CO2 change, during two, 2 min blocks). CVR was calculated as the %āCBF signal per mmHg change in end-tidal CO2. Aortic PWV data was acquired using a cine phase contrast velocity encoded series during 60 cardiac phases with a velocity encoding of 180cm/s through plane. PWV in the aortic arch was computed between ascending and descending aorta. Statistical analyses were done using SPSS.
Results: A moderation model test controlling for age and white matter hyperintensity volume revealed a significant direct effect of PWV on CVR (Ī²=1.630, 95% CI [.654, 2.607), as well as PWV on EF (Ī²=-.998, 95% CI [-1.697, -.299]). Sex moderated the relationship between PWV and CVR (Ī²=-1.013, 95% CI [-1.610, -.4169]), and PWV and EF (Ī²=.447, 95% CI [.020, .875]). In addition, there was a significant effect of HCT on the sex differences observed in the moderation effect (PWV*SEX) on EF (Ī²=-0.7680, SE = 0.3639 ,95% CI [-1.5047, -0.0314], p=0.0414).
Conclusion: Together, our results indicate that the relationships between PWV, CVR and EF is complex and in part mediated by sex and HCT. Future work should investigate the role of hormone variations (e.g., menopause) on these relationships to better personalize CVD prevention strategies
Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults
International audienceIt is well established that sex differences exist in the manifestation of vascular 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. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex