#4322 MEDIATION ANALYSIS OF THE RELATIONSHIP BETWEEN INFLAMMATION AND CONTRAST INDUCED ACUTE KIDNEY INJURY IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Background and Aims Decreased kidney function is a risk factor for the development of contrast-associated acute kidney injury (CA-AKI) in chronic kidney disease (CKD). Although the relationship between CKD and CA-AKI is well established, the mechanistic link between the two, particularly the extent to which this interaction is mediated by inflammation, remains poorly understood. We examined the association between CKD and CA-AKI, as well as potential mediators, including serum albumin and high-sensitivity C-reactive protein (hs-CRP) levels. Method A total of 3,738 patients were enrolled for analysis from 5,299 patients and fulfilled the inclusion criteria among 12,742 patients who underwent coronary angiography (CAG) between 1 January 2007, and 31 December 2016. Multivariable logistic regression and mediation analyses were performed. In addition to the effect as risk factors, direct and indirect effects were also estimated. Results Among 3,738 subjects, 414 developed AKI (11.1%). Pre-procedural albumin and Lnhs-CRP (log-transformed) were independently associated with CA-AKI (odds ratio [OR], 95% confidence interval [CI]): 0.320 (0.272–0.3787), P <0.001 and 1.211 (1.132-1.296), P<0.001, respectively. Direct, and indirect effects were also estimated. Patients with CKD were found to be more likely to exhibit lower serum albumin and higher serum hs-CRP levels. Simple mediation analyses showed that 33.8% and 52.3% of the relationship between CKD and CA-AKI was mediated by the serum albumin and hs-CRP levels, respectively with co-mediation being 13.9%. Conclusion These results represent that, in addition to reduced kidney function, inflammatory parameters are also risk factors and mediators of CA-AKI in patients with CKD.