Chirantan Banerjee, MD
Xiao L, Lan W, Sun W, Dai Q, Xiong Y, Li L, et al. Chronic Kidney Disease in Patients With Lacunar Stroke: Association With Enlarged Perivascular Spaces and Total Magnetic Resonance Imaging Burden of Cerebral Small Vessel Disease. Stroke. 2015
Renal and cerebrovascular beds share several physiologic characteristics like autoregulation and low resistance. Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease, cardiovascular mortality, as well as ischemic stroke. But the relationship is complicated, with several modifiers including traditional risk factors and race. A meta-analysis in 2010 (Lee et al) confirmed the association, as well as found a dose response relationship and a stronger relationship in Asian patients. Only African Americans were found to have an association between CKD and cardiovascular risk in a multi-ethnic cohort (NOMAS, Nickolas et al). Most of these studies are plagued by the issue of residual confounding by traditional cerebrovascular risk factors, as it is difficult to adjust for duration and severity of hypertension, diabetes etc.
In the current study, Xiao et al studied the association between CKD and markers of cerebral small vessel disease in patients with lacunar stroke. 413 consecutive patients with mean age of 64 years were prospectively enrolled at Jingling Hospital in Nanjing, China. 3T MRI was performed, with enlarged perivascular spaces (EPVS) at the level of basal ganglia and centrum semiovale chosen as the dependent biomarker, as it hasn’t been independently studied previously in this context. The authors also then computed a ordinal cerebral small vessel disease burden scale ranging 0-4, incorporating the four MRI markers lacune, white matter hyperintensities (WMH), cerebral microbleeds (CMBs), and EPVS. eGFR and proteinuria were dichotomized and chosen as the independent variables. Logistic regression was performed adjusting for potential confounders like age, sex, hypertension, diabetes, smoking, hyperlipidemia etc. as well as brain atrophy index. Both impaired GFR and proteinuria were found to be independently associated with increasing severity of EPVS, as well as cSVD burden on MRI.
This study adds to the growing evidence of CKD being associated with cerebral small vessel disease, with the fact that every single biomarker for cSVD was significantly associated speaking for itself. The fact that 3T MR was used in the study makes generalizability difficult as most centers still use 1.5T MR. Also, eGFR was calculated using CKD-EPI equation. Regardless, it again highlights the renocerebrovascular nexus. Whether they are causally related, or different phenotypic manifestations of the same underlying risk factors remains to be answered.