Reno-cerebrovascular disease: linking the nephron and neuron

Chronic kidney disease (CKD), a growing public health concern, carries a substantial burden and is a well-known independent predictor of coronary artery disease outcomes. In the last few years, attention has been focused on various CKD indices and their prognostic impact among individuals with, or at risk for, cerebrovascular disease. Mounting evidence suggests that the presence of CKD in various forms (filtration rate and barrier impairments), and even at mild stages, is associated with surrogate cerebrovascular disease markers, confers higher future risk of ischemic and hemorrhagic cerebrovascular events, and predicts poor clinical outcomes after an index stroke. However, a better understanding of these links is required. For instance, the direction and strength of the association of CKD with a heterogeneous vascular disease entity, such as cerebrovascular disease (vs coronary artery disease), appears to be greatly influenced by stroke type and ischemic stroke subtype, as well as CKD index and CKD stage. Furthermore, the potential mechanisms underlying the independent relation of baseline CKD and stroke risk need to be better delineated, since a causal association cannot be assumed. Additional investigation is also warranted to clarify whether CKD indices can usefully enhance cerebrovascular disease stratification beyond traditional risk factors. In the meantime, with several recent systematic reviews of published evidence supporting a robust and independent association of CKD with subsequent cerebrovascular disease risk, optimal implementation of established stroke risk reduction strategies in individuals with CKD might improve stroke outcomes. This article summarizes the compelling epidemiological and clinical evidence relating CKD to stroke, and presents the rationale for conducting future studies to assess the role of CKD as a risk marker or potential therapeutic target in individuals with, or at risk for, stroke.