Antiphospholipid antibodies and sub-clinical atherosclerosis in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort

Objective and design: Antiphospholipid antibodies (APA) have been associated with clinical cardiovascular disease, but it remains unclear whether APA are associated with sub-clinical atherosclerosis. This study examined the relationship between APA and sub-clinical atherosclerosis, measured as coronary artery calcification (CAC), in participants from the prospective Coronary Artery Risk Development in Young Adults (CARDIA) Study. Subjects and method: 2,203 black and white participants with sera available from the CARDIA year 7 examination and CAC measured by computed tomography at years 15 or 20 were selected. Results: Anti-β2-glycoprotein I (anti-β2-GPI) immunoglobulin (Ig) M, IgG, and IgA were positive in 7.0, 1.4, and 1.8 % of participants, respectively; anti-cardiolipin (aCL) IgM and IgG were positive in 1.5 and 1.0 %, respectively. 9.5 % of participants had CAC score >0 at year 15. Anti-β2-GPI IgM, IgG, IgA, and aCL IgG positivity were associated with CAC >0 at year 15 after adjustment for traditional cardiovascular risk factors; [odds ratios (95 % confidence intervals) were 1.7 (1.0, 3.1), 6.4 (2.4, 16.8), 5.6 (2.3, 13.2), and 5.1 (1.4, 18.6), respectively]. Anti-β2-GPI IgG was associated with year 20 CAC >0, and anti-β2-GPI IgA and aCL IgG were marginally associated. Conclusions: These findings indicate that APA positivity during young adulthood is a risk factor for subsequent sub-clinical atherosclerosis and might play a role in the pathogenesis of atherosclerosis.