(717.1) Sex differences in aortic hemodynamics and associations with white matter hyperintensities in middle-aged and older adults

Poster Board Number: E118

Andrew Pearson (University of Wisconsin - Madison), Kathleen Miller (University of Wisconsin - Madison), Adam Corkery (University of Wisconsin - Madison), Nicole Eisenmann (University of Wisconsin - Madison), Anna Howery (University of Wisconsin - Madison), Nathaniel Chin (University of Wisconsin - Madison School of Medicine and Public Health, University of Wisconsin - Madison School of Medicine and Public Health), Sterling Johnson (University of Wisconsin - Madison School of Medicine and Public Health, University of Wisconsin - Madison School of Medicine and Public Health, William S. Middleton Memorial Veterans Hospital), Jill Barnes (University of Wisconsin - Madison)

Elevated blood pressure (BP) in midlife increases the risk of developing white matter hyperintensities (WMH) in the brain. WMH are associated with increased risk of cognitive decline and dementia.  Structural changes of the large central arteries occur prior to changes in brachial BP. We have previously reported positive associations between aortic hemodynamics and WMH in normotensive postmenopausal women. The purpose of this study was to evaluate sex differences in aortic hemodynamics and associations with WMH burden in middle-aged and older adults. Ninety-nine participants (age = 63 ± 4y), including n = 35 men and n = 64 postmenopausal women participated in this study. Aortic hemodynamics were derived from radial artery pressure waveforms measured using applanation tonometry. Aortic systolic blood pressure (aSBP), aortic diastolic blood pressure (aDBP), augmented pressure (AP), aortic augmentation index (AIx), and aortic transit time were calculated. WMH lesion volume and intracranial volume (ICV) were measured using a FLAIR and T1 scan on a 3T MRI scanner, respectively. WMH fraction was calculated as (WMH lesion volume/ICV)*100 and cubic root transformed to reduce skewness. Age-adjusted multiple linear regressions were used to determine the influence of aortic hemodynamics on WMH fraction. There were no sex differences in aSBP or aDBP. AP was greater in women compared with men (16 ± 5 mmHg vs. 11 ± 5 mmHg; P lt; 0.001). AIx was also greater in women compared with men (28 ± 6 % vs. 18 ± 9 %; P lt; 0.001). Aortic transit time was lower in women compared with men (140 ± 11 ms vs. 151 ± 12 ms; P lt; 0.001). There were no sex differences in WMH fraction. There was a positive association between aSBP and WMH fraction in both men (r = 0.37, P = 0.015) and women (r = 0.36, P = 0.017). In addition, aDBP was positively associated with WMH fraction in men (r = 0.47, P = 0.003) and women (r = 0.36, P = 0.017). AP was positively associated with WMH fraction in men (r = 0.34, P = 0.027), but not women (r = 0.24, P = 0.296).  AIx was positively associated with WMH fraction in men (r = 0.46, P = 0.004), but not women (r = 0.22, P = 0.570). There were no significant associations between aortic transit time and WMH fraction. In conclusion, AP and AIx were greater in women compared with men. The positive associations between AP and WMH fraction and AIx and WMH fraction were only apparent in men. These findings suggest a sex-specific association between augmented pressure and augmentation index and WMH burden in middle-aged and older adults.

Support or Funding Information

This research was funded by NIH grant HL118154, Alzheimer’s Association Research Grant #17-499398, and Alzheimer’s Disease Research Center Grant: P30-AG062715.

This research was funded by NIH grant HL118154, Alzheimeramp;rsquo;s Association Research Grant #17-499398, and Alzheimeramp;rsquo;s Disease Research Center Grant: P30-AG062715.