Serum Sclerostin Level as a Biomarker of Aortic Aneurysm and Peripheral Atherosclerosis

Introduction: The data describing circulating sclerostin (SCL) levels in peripheral artery disease (PAD), carotid artery disease (CD), and aneurysms are inconsistent. We aimed to assess the performance of serum SCL levels as a biomarker of abdominal aortic aneurysm (AAA), PAD, and CD. Subjects and Methods: We conducted a single-center, cross-sectional study evaluating serum SCL levels (using ELISA) across different atherosclerosis phenotypes. We retrieved information from medical records on age, current smoking status, comorbidities, medications, lipid profile, and serum creatinine levels. Results: The mean age of 59 patients with AAA (22.0% women) was 75.4 ± 6.9 years and that of 163 patients with CD or PAD (56.2% women) was 71.5 ± 8.0 years. Men with AAA had increased SCL (0.90 ± 0.26 vs. 0.80 ± 0.26 ng/mL, p < 0.05). We calculated the Youden index-based cut-off for predicting AAA to be 0.73 ng/mL (AUC: 0.62; 95% CI: 0.51–0.72; sensitivity: 79.5%; specificity: 43.1%). In men, an increase in serum SCL levels by 1 ng/mL was associated with a higher risk of AAA occurrence, OR = 4.753 (95% CI: 1.103–20.486), in the univariate analysis. In women without AAA, SCL levels did not differ significantly between those with and without PAD regardless of CD coexistence, whereas they were higher in men with PAD and CD than in those without CD (0.92 ± 0.33 vs. 0.74 ± 0.20 ng/mL, p < 0.05). In the multivariate analysis, serum SCL levels were inversely associated with eGFR. Conclusions: Serum SCL levels are increased in men with atherosclerosis in large conduit arteries (AAA and CD); however, the low specificity of the cut-off and its relation to renal function preclude its use for AAA screening in men with atherosclerosis. Additionally, SCL levels are poorly related to the localization of atherosclerosis.