Cerebral pulsatility reflects a balance between the transmission and damping of pulsatility in the cerebrovasculature. Females experience greater cerebral pulsatility with aging which may have implications for sex differences in stroke risk and cognitive decline. This study sought to explore vascular contributors to cerebral pulsatility and pulsatile damping in men and women. 282 adults (53% female) underwent measurements of cerebral (middle cerebral artery) pulsatility, pulsatile damping (ratio of cerebral to carotid pulsatility), large artery stiffening (ratio of aortic to carotid pulse wave velocity), and carotid wave transmission/reflection dynamics using wave-intensity analysis. Multiple regression revealed older age, female sex, greater large artery stiffening, higher carotid pulse pressure, and greater forward wave energy was associated with increased cerebral pulsatility (adjusted R2=0.44, p<0.05). Contributors to decreased cerebral pulsatile damping included older age, female sex, and lower wave reflection index (adjusted R2=0.51, p<0.05). Our data link greater large artery stiffening, carotid pulse pressure, and forward wave energy to greater cerebral pulsatility, while greater carotid wave reflection may enhance cerebral pulsatile damping. Lower cerebral pulsatile damping among females may contribute to greater age-associated cerebral pulsatile burden compared to males.

Arterial stiffness is associated with cerebral flow pulsatility. Arterial stiffness increases following acute resistance exercise (RE). Whether this acute RE-induced vascular stiffening affects cerebral pulsatility remains unknown. Purpose: To investigate the effects of acute RE on common carotid artery (CCA) stiffness and cerebral blood flow velocity (CBFv) pulsatility. Methods: Eighteen healthy men (22 ± 1 yr; 23.7 ± 0.5 kg·m−2) underwent acute RE (5 sets, 5-RM bench press, 5 sets 10-RM bicep curls with 90 s rest intervals) or a time control condition (seated rest) in a randomized order. CCA stiffness (β-stiffness, Elastic Modulus (Ep)) and hemodynamics (pulsatility index, forward wave intensity, and reflected wave intensity) were assessed using a combination of Doppler ultrasound, wave intensity analysis and applanation tonometry at baseline and 3 times post-RE. CBFv pulsatility index was measured with transcranial Doppler at the middle cerebral artery (MCA). Results: CCA β-stiffness, Ep and CCA pulse pressure significantly increased post-RE and remained elevated throughout post-testing (p < 0.05). No changes in MCA or CCA pulsatility index were observed (p > 0.05). There were significant increases in forward wave intensity post-RE (p < 0.05) but not reflected wave intensity (p > 0.05). Conclusion: Although acute RE increases CCA stiffness and pressure pulsatility, it does not affect CCA or MCA flow pulsatility. Increases in pressure pulsatility may be due to increased forward wave intensity and not pressure from wave reflections.

Objective To investigate racial differences in central blood pressure and vascular structure/function as subclinical markers of atherosclerotic cardiovascular disease (CVD) in children. Study design This cross-sectional study recruited 54 African-American children (18 female, 36 male; age 10.5 ± 0.9) and 54 white children (27 female, 26 male; age 10.8 ± 0.9) from the Syracuse City community as part of the Environmental Exposures and Child Health Outcomes (EECHO) study. Participants underwent blood lipid and vascular testing on two separate days. Carotid artery intima-media thickness (IMT) and aortic stiffness were measured via ultrasonography and carotid-femoral pulse wave velocity (PWV), respectively. Blood pressure (BP) was assessed at the brachial artery and estimated in the carotid artery using applanation tonometry. Results African American children had significantly higher PWV (4.8 ± 0.8 m/s) compared with white children (4.2 ± 0.7 m/s; p<0.05) which remained significant after adjustment for confounding variables including socioeconomic status. African-American children had significantly higher IMT (African-American 0.41 ± 0.06, white 0.39 ± 0.05 mm), and carotid systolic BP (African-American 106 ± 11, white 102 ± 8 mmHg; p<0.05) compared with white children, although these racial differences were no longer present after covariate adjustments for height. Conclusions Racial differences in aortic stiffness are present in childhood. Our findings suggest that racial differences in subclinical CVD occur earlier than previously recognized.

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