Adipokines and severity and progression of coronary artery calcium: Findings from the Rancho Bernardo Study

Background and aims: Adipokines are known to predict cardiovascular events, yet their association with coronary artery calcium (CAC), a surrogate marker of coronary atherosclerosis and risk factor for cardiovascular disease (CVD), is unclear. We aimed at assessing the association between adipokines and the severity and progression of CAC in healthy older adults, and at exploring potential modification by gender. Methods: 409 men and women from the Rancho Bernardo Study with no known CVD underwent a chest computed tomography scan to determine baseline CAC severity; 329 returned 4.5 years later for a repeat scan to evaluate CAC progression. Adipokines (IL-6, adiponectin, leptin, and TNF-alpha) were measured from baseline blood samples. Ordinal linear and logistic regression models were used to determine the association of each adipokine with baseline severity and future progression of CAC. Results: Adjusting for age and sex, IL-6 and leptin were associated with greater odds of increasing CAC severity (OR = 1.63, 95% CI 1.22-2.19; OR = 1.19, 95% CI 0.99-1.43, respectively, per SD). The association with IL-6 remained significant in models further adjusted for lifestyle, body size, CVD risk factors, and body fat distribution. Adiponectin was associated with CAC progression (OR = 0.68, 95% CI 0.51-0.92 in fully adjusted models). This was modified by sex, with protective effects seen for men (OR = 0.57, 95% CI 0.38-0.85), but not for women (OR = 0.93, 95% CI 0.67-1.32; p-for-interaction = 0.04). Conclusions: IL-6 and leptin predicted greater CAC severity while adiponectin predicted lower odds of CAC progression. More research is needed to explore biological mechanisms, including differences by sex. (C) 2017 Elsevier B.V. All rights reserved.