Reno-cerebrovascular disease?

Chronic kidney disease (CKD) is a growing national concern and global public health problem, which affects nearly 20 million people in the United States alone.¹ Two articles in this issue of Neurology consider neurologic complications of CKD.^2,3 A number of well-known risk factors for stroke and TIA are also associated with risk of CKD. For example, diabetes mellitus and hypertension are the primary causes of kidney failure in approximately 75% of dialysis patients. In fact, by the time dialysis is initiated, more than 70% of patients with CKD have four to six comorbidities. Besides diabetes and hypertension, dialysis patients often have congestive heart failure, atherosclerotic heart disease, and TIA or stroke.⁴ In addition to vascular risk factors and diseases, patients with CKD are predisposed to oxidative stress, inflammation, elevated homocysteine levels, anemia, and vascular calcification,^5,6 all of which have been associated with impaired neurologic function. Thus, it is not surprising that patients with CKD have a variety of neurologic conditions including cerebrovascular disease and cognitive impairment. However, it is becoming increasingly evident that impaired kidney function may confer a significant additional risk for impaired neurologic function and death separate from the vascular risk factors associated with the development of kidney disease.^5,7–10

A recent review of large dialysis and hospital discharge databases revealed that dialysis patients are at increased risk of ischemic stroke ranging from about a fourfold increase in African American men to about a 10-fold increase in white women relative to the general population.¹¹ Data conflict as to whether CKD increases the risk of stroke among predialysis patients. In a study combining four large community-based data sets, including the Framingham Heart Study and the Atherosclerosis Risk in Communities (ARIC) Study, with a combined sample size in excess of 20,000, predialysis patients did not …