AOPEP and chronic kidney disease: While the crude analyses provided strong evidence of an association between an increasing number of vascular beds and evidence of atherosclerosis and cognitive impairment, there was evidence that the relationship between atherosclerotic burden and cognitive impairment was negatively and positively confounded by APO e4 carrier status, type 2 diabetes mellitus, age group, and CKD (Additional file 1: Table S3).