Relation of Sex Hormone Levels with Prevalent and 10-Year Change in Aortic Distensibility Assessed by MRI: The Multi-Ethnic Study of Atherosclerosis

Background: Women experience a steeper decline in aortic elasticity related to aging compared to men. We examined whether sex hormone levels were associated with ascending aortic distensibility (AAD) in the Multi-Ethnic Study of Atherosclerosis. Methods: We studied 1,345 postmenopausal women and 1,532 men aged 45-84 years, who had serum sex hormone levels, AAD measured by phase-contrast cardiac magnetic resonance imaging, and ejection fraction>50% at baseline. Among these participants, 457 women and 548 men returned for follow-up magnetic resonance imaging 10-years later. Stratified by sex, and using mixed effects linear regression methods, we examined associations of sex hormones (as tertiles) with baseline and annual change in log-transformed AAD (mm Hg^-110^-3), adjusting for demographics, body size, lifestyle factors, mean arterial pressure, heart rate, hypertensive medication use (and in women, for hormone therapy use and years since menopause). Results: The mean (SD) age was 65 (9) for women and 62 (10) years for men. AAD was lower in women than men (P < 0.001). In adjusted cross-sectional analysis, the highest tertile of free testosterone (compared to lowest) in women was significantly associated with lower AAD [-0.10 (-0.19, -0.01)] and the highest tertile of estradiol in men was associated with greater AAD [0.12 (0.04, 0.20)]. There were no associations of sex hormones with change in AAD over 10 years, albeit in a smaller sample size. Conclusions: Lower free testosterone in women and higher estradiol in men were associated with greater aortic distensibility at baseline, but not longitudinally. Sex hormone levels may account for differences in AAD between women and men.