Positive association between abdominal aortic diameter and serum collagen XVIII levels

The identification of abdominal aortic aneurysm (AAA) biomarker offers a perspective to determine disease progress and rupture risk. The aim of our study was to evaluate the association between selected circulating biomarkers and diameter of abdominal aorta.One hundred and two patients (88 men and 14 women) with mean age 70.0±8.7 years were included in a single center cross-sectional study conducted between February 2016 and October, 2018. AAA was defined as subrenal aortic dilatation ≥3 cm. Serum biomarker concentrations (insulin-like growth factor-1, peroxiredoxin-1, collagen IV, collagen XVIII) were measured by an enzyme-linked immunosorbent assay (ELISA). Adjustments including variables with different baseline distribution at univariate level with P<0.1 (age, body mass index, coronary artery disease, fibrinogen) were performed in multivariate models.Higher collagen XVIII was found in AAA patients in comparison with the control group of patients (39.5 vs. 25.0 ng/mL; P=0.002). Diameter of abdominal aorta was positively associated with collagen XVIII levels in univariate (B=0.16; P=0.004), and in multivariate analysis (B=0.14; P=0.027), i.e. increase in collagen XVIII by 1 ng/mL corresponded to an increase in abdominal aortic diameter by 0.14 mm. Patients with serum collagen XVIII levels in the third tertile (˃47 ng/mL) had 4.23 times higher risk of AAA compared to patients with collagen XVIII levels in the first and second tertiles (OR 4.23; 95% CI 1.42-11.6; P=0.020). No association was found between other examined biomarkers and abdominal aortic diameter.Diameter of abdominal aorta was positively associated with serum collagen XVIII level.