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

Abstract

After ischemic stroke, kidney dysfunction is linked to poor outcomes in the elderly, but regarding young patients, data are lacking. 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. 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. Despite their different associated risk factors in our young patient cohort, both low and high eGFR predicted long-term mortality after ischemic stroke.