A constitutive modeling interpretation of the relationship among carotid artery stiffness, blood pressure, and age in hypertensive subjects.

Autor:	Spronck B; Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands; b.spronck@maastrichtuniversity.nl., Heusinkveld MH; Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands;, Donders WP; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Biomedical Engineering, MHeNS School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands; and., de Lepper AG; Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands;, Op't Roodt J; Department of Internal Medicine, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands., Kroon AA; Department of Internal Medicine, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands., Delhaas T; Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands;, Reesink KD; Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands;
Jazyk:	angličtina
Zdroj:	American journal of physiology. Heart and circulatory physiology [Am J Physiol Heart Circ Physiol] 2015 Mar 15; Vol. 308 (6), pp. H568-82. Date of Electronic Publication: 2014 Dec 24.
DOI:	10.1152/ajpheart.00290.2014
Abstrakt:	Aging has a profound influence on arterial wall structure and function. We have previously reported the relationship among pulse wave velocity, age, and blood pressure in hypertensive subjects. In the present study, we aimed for a quantitative interpretation of the observed changes in wall behavior with age using a constitutive modeling approach. We implemented a model of arterial wall biomechanics and fitted this to the group-averaged pressure-area (P-A) relationship of the "young" subgroup of our study population. Using this model as our take-off point, we assessed which parameters had to be changed to let the model describe the "old" subgroup's P-A relationship. We allowed elastin stiffness and collagen recruitment parameters to vary and adjusted residual stress parameters according to published age-related changes. We required wall stress to be homogeneously distributed over the arterial wall and assumed wall stress normalization with age by keeping average "old" wall stress at the "young" level. Additionally, we required axial force to remain constant over the cardiac cycle. Our simulations showed an age-related shift in pressure-load bearing from elastin to collagen, caused by a decrease in elastin stiffness and a considerable increase in collagen recruitment. Correspondingly, simulated diameter and wall thickness increased by about 20 and 17%, respectively. The latter compared well with a measured thickness increase of 21%. We conclude that the physiologically realistic changes in constitutive properties we found under physiological constraints with respect to wall stress could well explain the influence of aging in the stiffness-pressure-age pattern observed. (Copyright © 2015 the American Physiological Society.)
Databáze:	MEDLINE
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