MMP2 and atherosclerosis: Studies involving CKD patients that did not use atherosclerosis measures as an outcome were excluded at the last step, prior to quantitative synthesis, in order to limit the results of this study to objective atherosclerosis measures as opposed to clinical or self-reported measures such as “history of CVD.” Notably, in these studies, circulating levels of MMP-2 were associated with previous history of CVD in a non-HD CKD population [44] and in a Peritoneal Dialysis (PD) population [45], providing further supporting evidence for MMP-2 association with CVD in CKD (Supplementary Table  1).