Supplementary Material for: Chronic Kidney Disease and Cognitive Impairment: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Chronic kidney disease (CKD) has emerged as a possible new risk factor of cognitive impairment and dementia, but results of studies remain conflicting. <b><i>Methods:</i></b> A systematic literature research of electronic databases (MEDLINE, Cochrane Library and Goggle Scholar covering the period from 1980 to January 2012) and meta-analysis of relevant cross-sectional and longitudinal studies were conducted to assess the association of CKD and cognitive decline. <b><i>Results:</i></b> Most cross-sectional and longitudinal studies suggest an association between cognitive impairment and CKD. Meta-analysis of cross-sectional and longitudinal studies comprising 54,779 participants yielded an association of cognitive decline in patients with CKD compared with patients without CKD (OR 1.65, 95% CI 1.32–2.05; p &lt; 0.001, and OR 1.39, 95% CI 1.15–1.68; p &lt; 0.001, respectively). <b><i>Conclusion:</i></b> This is the first meta-analysis assessing the impact of CKD on cognitive decline. Our results suggest CKD being a significant and independent somatic risk factor in the development of cognitive decline.