The relationship between abdominal aortic aneurysm distensibility and serum markers of elastin and collagen metabolism.

Abstract

abdominal aortic aneurysm (AAA) distensibility may be an independent predictor of growth and rupture, possibly because it reflects changes in aortic wall structure and composition. to determine whether AAA distensibility is related to circulating markers of elastin and collagen metabolism. sixty-two male patients of median age (IQR) 68 (65-72) years with asymptomatic AAA of median (IQR) diameter 42 (37-45) mm were prospectively studied. Pressure-strain elastic modulus (Ep) and stiffness (beta) were measured using an ultrasonic echo-tracker (Diamove). Serum elastin peptides (SEP), plasma elastin-alpha1-antitrypsin complex (E-AT), procollagen III-N-terminal propeptide (PIIINP) were measured by enzyme-linked immunoassay. age and smoking adjusted Ep and beta were significantly inversely related to SEP (r=-0.33 and r=-0.31 respectively, both p<0.02) and E-AT (r=-0.27 and r=-0.27 respectively, both p<0.05) both of which indicate elastolysis. By contrast, there was a significant positive correlation between PIIINP, indicative of increased collagen turn-over, and both Ep and beta (both r=0.45, p<0.01 unadjusted correlations). increased elastolysis is associated with increased AAA wall distensibility; whereas increased collagen turn-over is associated with reduced distensibility.