Sex and age differences in the association between sympathetic outflow and central elastic artery wall thickness in humans.

Sex and age differences in the association between sympathetic outflow and central elastic artery wall thickness in humans. Am J Physiol Heart Circ Physiol. 2019 Jul 05;: Authors: Holwerda SW, Luehrs RE, DuBose LE, Majee R, Pierce GL Abstract Aging is characterized by increased wall thickness of the central elastic arteries (i.e., aorta and carotid arteries), although the mechanisms involved are unclear. Evidence suggests that age-related increases in muscle sympathetic nerve activity (MSNA) may be a contributing factor. However, studies in humans have been lacking. Therefore, we tested the hypothesis that age-related increases in MSNA would be independently associated with carotid artery intima-media thickness (IMT), but not in young women given the reduced influence of MSNA on the vasculature in this group. In 93 young and middle-age/older (MA/O) adults (19-73 years, 41 women), we performed assessments of MSNA (microneurography) and common carotid IMT and lumen diameter (ultrasonography). Multiple regression that included MSNA and other CVD risk factors indicated that MSNA (P=0.002) and 24-hour systolic blood pressure (BP) (P=0.024) were independent determinants of carotid IMT-to-lumen ratio (model R2=0.38, P<0.001). However, when examining only young women (<45yrs), no correlation was observed between MSNA and carotid IMT-to-lumen ratio (R=-0.01, P=0.963). MSNA was significantly correlated with IMT-to-lumen ratio while contr...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research