Chronic kidney disease and stroke

We appreciate the idea of cerebrorenal interaction, as proposed by Toyoda and colleagues in their recent Review,1Toyoda K Ninomiya T Stroke and cerebrovascular diseases in patients with chronic kidney disease.Lancet Neurol. 2014; 13: 823-833Summary Full Text Full Text PDF PubMed Scopus (208) Google Scholar because it raises an important clinical issue with respect to chronic kidney disease in patients with stroke and cerebrovascular disease. The authors describe the mechanisms by which kidney disease might increase the risk of stroke and subclinical cerebral abnormalities, and affect cognitive function. However, the effect of stroke or cerebrovascular disease on renal function has scarcely been explored, which makes the comprehensive description of this two-way interaction more challenging than that of its cardiology counterpart, cardiorenal syndrome.2Ronco C Haapio M House AA Anavekar N Bellomo R Cardiorenal syndrome.J Am Coll Cardiol. 2008; 52: 1527-1539Crossref PubMed Scopus (1425) Google Scholar Reports3Covic A Schiller A Mardare NG et al.The impact of acute kidney injury on short-term survival in an Eastern European population with stroke.Nephrol Dial Transplant. 2008; 23: 2228-2234Crossref PubMed Scopus (65) Google Scholar, 4Tsagalis G Akrivos T Alevizaki M et al.Renal dysfunction in acute stroke: an independent predictor of long-term all combined vascular events and overall mortality.Nephrol Dial Transplant. 2009; 24: 194-200Crossref PubMed Scopus (126) Google Scholar on hospital admissions show that 14·5–26·7% of patients with acute stroke develop acute kidney injury, which is itself an independent predictor of short-term and long-term outcomes after stroke. Kidney damage due to dehydration and electrolyte imbalance as a result of dysphagia and reactive hypertension after stroke, and the use of nephrotoxic drugs such as mannitol in the treatment of stroke might lead to acute kidney injury. Contrast medium for the diagnosis or endovascular treatment of stroke might lead to acute kidney injury in patients with acute stroke. Future research might be warranted on the question of whether the prevention of acute kidney injury improves outcomes in patients with acute stroke. More than a third of patients with acute stroke have an estimated glomerular filtration rate of less than 60 mL/min per 1·73 m2 when admitted, but this might relate to a transient increase in serum creatinine concentration resulting either from the stroke or treatments.1Toyoda K Ninomiya T Stroke and cerebrovascular diseases in patients with chronic kidney disease.Lancet Neurol. 2014; 13: 823-833Summary Full Text Full Text PDF PubMed Scopus (208) Google Scholar According to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative,5National Kidney FoundationK/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification.Am J Kidney Dis. 2002; 39: S1-266Summary Full Text Full Text PDF PubMed Scopus (233) Google Scholar chronic kidney disease should be defined as persistently decreased estimated glomerular filtration rate and proteinuria for at least 3 months. The prevalence of chronic kidney disease in patients with acute stroke therefore remains uncertain, because it is not clear whether renal changes persist beyond the acute phase. We declare no competing interests. Stroke and cerebrovascular diseases in patients with chronic kidney diseaseChronic kidney disease, defined as a reduced glomerular filtration rate or increased urinary albumin excretion, is recognised as a rapidly growing global health burden, and increasing evidence suggests that it contributes to the risk and severity of cerebrovascular diseases. In particular, chronic kidney disease is an established risk factor for stroke and is also strongly associated with subclinical cerebrovascular abnormalities and cognitive impairment, partly because it shares several traditional and non-traditional risk factors, and sometimes uraemia-related and dialysis-related factors, with cerebrovascular diseases. Full-Text PDF Chronic kidney disease and stroke–Authors' replyWe thank Cheng-Yang Hsieh and colleagues for their interest in our Review.1 The effect of stroke on kidney function is an important point to consider in terms of cerebrorenal interactions. In 7 068 334 patients admitted to hospital with acute ischaemic stroke as part of the US Nationwide Inpatient Sample from 2002 to 2010,2 372 223 patients had acute renal failure that was independently associated with moderate to severe disability (odds ratio [OR] 1·3, 95% CI 1·3–1·4), intracerebral haemorrhage (1·4, 1·3–1·6), and death (2·2, 2·0–2·2) after multivariable adjustment. Full-Text PDF