Abstract P298: Association of Serum Sclerostin with Vascular Calcification in African Ancestry Men

Abstract

Objective: Sclerostin, a Wnt pathway antagonist, is an established regulator of bone mineralization in humans but its potential importance in the regulation of vascular calcification is less clear. Therefore, our objective was to assess the relationship of serum sclerostin levels with coronary and aortic artery calcification (CAC and AAC, respectively) in African ancestry men on the island of Tobago. Methods: Detailed health history, clinical exam and computed tomography scans of CAC and AAC were obtained in 191 men aged ≥40 years (mean(SD): 62.9(8.0)years) recruited without regard to health status. Fasting serum samples were drawn and stored at -80°C until time of assay. Serum sclerostin levels were measured using ELISA according to manufacturer’s protocol (Biomedica Gruppe, Vienna, Austria). Multivariable logistic regression models were used to assess the cross-sectional association of sclerostin with prevalent arterial calcification. Results: In unadjusted analyses, the 57 of 191 (29.8%) of men with CAC were older, more likely to be hypertensive, had lower kidney function and had greater serum sclerostin (all P-values<0.05). The 131 of 191 (68.6%) of men with AAC were also older and more likely to be hypertensive, but they had greater total body fat and were more likely to be on statins, as well (all P-values<0.05). Mean(SD) sclerostin was 45.2 pmol/l (15.6 pmol/l). After adjusting for risk factors including age, physical and lifestyle characteristics, comorbidities, lipoproteins and kidney function, 1 SD greater sclerostin level was associated with 1.61-times (95%CI 1.02-2.53) greater odds of having CAC. Sclerostin was not associated with AAC in any model. Conclusions: This is the first study to show that, among African ancestry men, greater serum sclerostin levels were associated with CAC. In addition to its known role in bone mineralization, the Wnt antagonist, sclerostin, may also play a role in calcification of the coronary arteries.