Investigating relationships between arterial stiffness and collagen turnover in humans

Understanding the factors regulating changes in vascular structure may assist in designing strategies for decreasing the development and progression of cardiovascular disease. Previous research has shown links between various markers of collagen turnover and arterial stiffness in clinical populations (McNulty, 2006 & Chatzikyriakou, 2008). The purpose of this study was to investigate the relationship between functional assessments and blood markers of arterial wall structure. Arterial stiffness and markers of collagen turnover were assessed in 20 overweight women, 20 elderly healthy men, 23 individuals with coronary artery disease, 16 individuals with spinal cord injury and 10 young healthy men. Carotid artery stiffness was determined through assessment of common carotid artery distensibility with simultaneous B‐mode ultrasound imaging and applanation tonometry. Fasting venous blood samples were analyzed for serum levels of pro‐collagen type I (PIP) and cross‐linked telopeptide of collagen type I (CTX); markers of type I collagen synthesis and degradation, respectively. There was a significant positive relationship observed between CTX and carotid artery distensibility (R = 0.330, p = 0.001) and a weak but significant inverse relationship (R = −0.224, p = 0.034) observed between carotid artery distensibility and type I collagen turnover, expressed as a ratio of PIP to CTX. These findings suggest a link exists between type I collagen turnover and central arterial distensibility, however this relationship appears to be opposite to that previous observed in the literature in older hypertensive individuals (McNulty, 2006). Funded by Canadian Institute of Health Research, Natural Sciences and Engineering Research Council, Innovation Center for US Dairy, Dairy Farmers of Canada and the Ontario Neurotrauma Foundation.