Impairment in glomerular filtration rate or glomerular filtration barrier and occurrence of stroke

Background: Chronic kidney disease ( CKD) is associated with substantial burden and is a strong risk factor for cardiovascular disease. However, data on the relationship between CKD and stroke are few and are limited by unreliable or inadequate assessment of renal function. Objective: To properly assess the relationship between renal insufficiency and stroke in stroke survivors in the United States by simultaneously examining the effect of guideline- recommended indices of renal disease that measure glomerular filtration rate ( creatinine clearance) and glomerular filtration barrier ( proteinuria). Design: Cross sectional. Setting: Nationally representative survey of the United States. Subjects: Participants aged 55 or older who participated in the National Health and Nutrition Examination Survey from 1999 to 2004. Main Outcome Measures: Indices of renal disease that measure glomerular filtration rate (creatinine clearance) and glomerular filtration barrier ( microalbuminuria). Results: Of 6382 adults who met inclusion criteria, 5624 ( 88%) had full and complete data, of which 414 ( 6%) reported having had a stroke. Stroke survivors were older and more likely to have CKD, diabetes, hypertension, coronary artery disease, elevated blood pressure, increased glycohemoglobin concentration, and lower hematocrit compared with respondents who did not report stroke. Multivariate models showed that microalbuminuria ( odds ratio, 1.51; 95% confidence interval, 1.02- 2.24), decreased glomerular filtration rate ( odds ratio, 1.93; 95% confidence interval, 1.28- 2.91), and stage 3 CKD ( odds ratio, 2.09; 95% confidence interval, 1.38- 3.16) were significantly associated with stroke. Conclusion: Stroke is independently associated with impairment in structure and function of the glomerulus, which supports the need to consider screening patients with stroke forCKDand to simultaneously assess for both indices of renal disease.