Vascular Aging: Assessment and Intervention

Abstract

Vascular aging represents a collection of structural and functional changes in a blood vessel with advancing age, including increased stiffness, vascular wall remodeling, loss of angiogenic ability, and endothelium-dependent vasodilation dysfunction. These age-related alterations may occur earlier in those who are at risk for or have cardiovascular diseases, therefore, are defined as early or premature vascular aging. Vascular aging contributes independently to cardio-cerebral vascular diseases (CCVDs). Thus, early diagnosis and interventions targeting vascular aging are of paramount importance in the delay or prevention of CCVDs. Here, we review the direct assessment of vascular aging by examining parameters that reflect changes in structure, function, or their compliance with age including arterial wall thickness and lumen diameter, endothelium-dependent vasodilation, arterial stiffness as well as indirect assessment through pathological studies of biomarkers including endothelial progenitor cell, lymphocytic telomeres, advanced glycation end-products, and C-reactive protein. Further, we evaluate how different types of interventions including lifestyle mediation, such as caloric restriction and salt intake, and treatments for hypertension, diabetes, and hyperlipidemia affect age-related vascular changes. As a single parameter or intervention targets only a certain vascular physiological change, it is recommended to use multiple parameters to evaluate and design intervention approaches accordingly to prevent systemic vascular aging in clinical practices or population-based studies.

Keywords: arterial stiffness; arterial wall thickness; endothelial function; therapeutic intervention; vascular aging.

Figure 1

IMT in young and old arteries. The hematoxylin-eosin staining of tissue sections from digital artery (DA, 21-year old, (A1)) and anterior tibial artery (ATA, 70-year old, (A2)). Tissues were obtained from male patients who had radical surgeries for polydactyly and malignant melanoma of lower extremity, respectively, sectioned at 4 micrometers, and fixed with 4% polyformaldehyde for 24 hour prior to staining. The IMT was only measured and pointed in ATA and the tunica media layers were labeled with dash lines as IMT was too thin to be measured accurately. (B1 and B2) are B-mode ultrasound images of carotid arteries from two male patients at the ages of 33 (IMT = 0.09 cm) and 74 year (IMT = 0.13 cm). The intimal-medial layers were labeled with dash lines. The positions for measuring IMT were pointed with yellow crosses.

Figure 2

Functional shift with increased ages. (A) Endothelium-dependent vascular relaxation induced by acetylcholine for the artery rings from young and old man. The cumulative concentration response curves were recorded, and statistical significance was indicated with asterisks (*). (B) brachial-ankle pulse wave velocity (baPWV) was measured in men (red) and women (blue) at ages from 60 to 95 years. The baPWV is increased with ages but not different between genders.