Factors Associated With Impaired Kidney Function and Its Impact on Long-Term Outcome in Young Ischemic Stroke

Background and Purpose-After ischemic stroke, kidney dysfunction is linked to poor outcomes in the elderly, but regarding young patients, data are lacking. Methods-We investigated estimated glomerular filtration rate (eGFR) on admission according to the Modification of Diet in Renal Disease equation in 958 consecutive patients aged 15 to 49 years with their first-ever ischemic stroke. Logistic regression adjusted for demographics and stroke risk factors served to identify factors related to low (<60) and high (>120 mL/min/ 1.73 m(2)) eGFR. In the long-term follow-up (mean, 8.9 +/- 3.8 years) study, Cox proportional hazards analysis described the association between eGFR and the following end points: nonfatal/fatal ischemic stroke; composite vascular event of any stroke, myocardial infarction, revascularization/other arterial occlusive event, or vascular death; and death of any cause. Results-Estimated GFR was normal in 809 (84.4%), low in 43 (4.5%), and high in 106 (11.1%) patients. Type 1 diabetes (OR, 18.84; 95% CI, 8.65 to 41.03), hypertension (4.29; 1.94 to 9.48), and cardiovascular disease (2.66; 1.19 to 5.96) were independently associated with low eGFR. Type 2 diabetes (3.82; 1.93 to 7.55), lower age (0.95 per year; 0.93 to 0.98), and male gender (1.74; 1.08 to 2.82) were associated with high eGFR. Both low (hazard ratio, 5.73; 95% CI, 3.54 to 9.25) and high eGFR (1.78; 1.01 to 3.14) were associated with long-term mortality when adjusted for age, gender, risk factors, stroke severity, and subtype. No independent association appeared between eGFR and vascular events. Conclusions-Despite their different associated risk factors in our young patient cohort, both low and high eGFR predicted long-term mortality after ischemic stroke. (Stroke. 2011;42:2459-2464.)