Hindawi Publishing Corporation Cardiology Research and Practice Volume 2012, Article ID 806102, 8 pages doi:10.1155/2012/806102 Research Article The Association of Chronic Kidney Disease and Metabolic Syndrome with Incident Cardiovascular Events: Multiethnic Study of Atherosclerosis Subhashish Agarwal,1 Michael G. Shlipak,2 Holly Kramer,3 Aditya Jain,4 and David M. Herrington1 1 Cardiology Section, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA 2 General Internal Medicine Division, San Francisco VA Medical Center and the University of California San Francisco, San Francisco, CA 94143, USA 3 Department of Preventive Medicine and Division of Nephrology and Hypertension, Loyola University Medical Center, Maywood, IL 60153, USA 4 Department of Radiology, John Hopkins University, Baltimore, MD 21205, USA Correspondence should be addressed to Subhashish Agarwal, sa1972@gmail.com Received 21 April 2011; Accepted 22 June 2011 Academic Editor: Anjali Arora Copyright © 2012 Subhashish Agarwal et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. There is an association between chronic kidney disease (CKD) and metabolic syndrome (MetS). We examined the joint association of CKD and MetS with incident cardiovascular (CVD) events in the Multiethnic Study of Atherosclerosis (MESA) cohort. Methods. We analyzed 2,283 Caucasians, 363 Chinese, 1,449 African-Americans, and 1,068 Hispanics in the MESA cohort. CKD was deﬁned by cystatin C estimated glomerular ﬁltration rate ≤ 60 mL/min/1.73 m2 and MetS was deﬁned by NCEP criteria. Cox proportional regression adjusting for age, ethnicity, gender, study site, education, income, smoking, alcohol use, physical activity, and total and LDL cholesterol was performed to assess the joint association of CKD and MetS with incident CVD events. Participants were divided into four groups by presence of CKD and/or MetS and compared to the group without CKD and MetS (CKD−/MetS−). Tests for additive and multiplicative interactions between CKD and MetS and prediction of incident CVD were performed. Results. During follow-up period of 5.5 years, 283 participants developed CVD. Multivariate Cox regression analysis demonstrated that CKD and MetS were independent predictors of CVD (hazard ratio, 2.02 for CKD, and 2.55 for MetS). When participants were compared to the CKD−/MetS− group, adjusted HR for the CKD+/MetS+ group was 5.56 (95% CI 3.72–8.12). There was no multiplicative interaction between CKD and MetS (P = 0.2); however, there was presence of additive interaction. The relative excess risk for additive interaction (RERI) was 2.73, P = 0.2, and the attributable portion (AP) was 0.49 (0.24–0.74). Conclusion. Our ﬁndings illustrate that the combination of CKD and MetS is a strong predictor of incident clinical cardiovascular events due to presence of additive interaction between CKD and MetS. 1. Introduction A large percentage of the US population (10%) suﬀers from chronic kidney disease (CKD) [1] which is associated with metabolic syndrome [2–4]. Metabolic syndrome (MetS) is a construct of physical and laboratory anomalies that confers a higher risk for diabetes mellitus, cardiovascular events and mortality. The National Cholesterol Education Program Adult Treatment Panel (ATP III) criteria deﬁne MetS as having at least three of the following: abdominal or central obesity; high triglyceride levels; low high-density lipoprotein (HDL) cholesterol; hyperglycemia; hypertension [5], which has high prevalence in the US [6]. Both CKD [7–9] and MetS [10, 11] have been shown to be independently associated with increased cardiovascular events and mortality, and studies suggest that CKD and MetS are associated with each other as well [2–4]. The increased cardiovascular risk of kidney disease is partly explained by