Carotid distensibility characterized via the isometric exercise pressor response

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 283; no. 6; pp. H2592 - H2598
• Main Authors: Myers, Christopher W, Farquhar, William B, Forman, Daniel E, Williams, Todd D, Dierks, Dustin L, Taylor, J. Andrew
• Format: Journal Article
• Language: English
• Published: United States 01.12.2002
• Subjects: Adult; Age Distribution; Age Factors; Blood Pressure - physiology; Carotid Arteries - diagnostic imaging; Carotid Arteries - physiology; Elasticity; Exercise - physiology; Female; Hand Strength - physiology; Humans; Male; Middle Aged; Reference Values; Sex Distribution; Sex Factors; Tilt-Table Test; Tunica Intima - diagnostic imaging; Tunica Media - diagnostic imaging; Ultrasonography
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00309.2002

Laboratory for Cardiovascular Research, Hebrew Rehabilitation Center for Aged, Beth Israel Deaconess Medical Center, and Division on Aging, Harvard Medical School, Boston, Massachusetts 02131 Distensibility of the large elastic arteries is a key index for cardiovascular health. Distensibility, usually estimated from resting values in humans, is not a static characteristic but a negative curvilinear function of pressure. We hypothesized that differences in vascular function with gender and age may only be recognized if distensibility is quantified over a range of pressures. We used isometric handgrip exercise to induce progressive increases in pressures and carotid diameters, thereby enhancing the characterization of distensibility. In 30 volunteers, evenly distributed by gender and age across the third to fifth decades of life, we derived pulsatile distensibility slopes as a function of arterial pressure for a dynamic distensibility index and compared it with a traditional static index at a reference pressure of 95 mmHg. We also assessed intima-media thickness (IMT). We found that women had greater distensibility slopes within each decade, despite comparable IMT. Furthermore, declines in distensibility slope with increasing age were correlated to increased IMT. The static distensibility index failed to show gender-related differences in distensibility but did show age-related differences. Our results indicate that gender- and age-related differences can be manifest even in young, healthy adults and may only be identified with techniques that assess carotid distensibility across a range of pressures. carotid arteries; ultrasonography; compliance; vascular