Strong Independent Correlation of Proteinuria With Cerebral Microbleeds in Patients With Stroke and Transient Ischemic Attack

Objective: To assess the association of proteinuria with the frequency and number of cerebral microbleeds (CMB), a harbinger of future hemorrhagic stroke. Design: Cross-sectional analysis. Patients: Patients with consecutive ischemic stroke and transient ischemic attack admitted to a university hospital during a 22-month period. Interventions: Presence and number of CMB were evaluated using gradient-echo T2*-weighted magnetic resonance imaging. Multivariable models were generated to determine the contribution of proteinuria to the frequency and number of CMB after adjusting for confounders. Results: Of 236 patients (mean age, 70 years; 53% female), 72 (31%) had CMB present on gradient-echo imaging and 89 (38%) had evidence of proteinuria. In multivariable analyses with presence of CMB as the outcome, higher urinary protein (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.10-4.95), being female (OR, 2.29; 95% CI, 1.19-4.49), history of atrial fibrillation (OR, 2.49; 95% CI, 1.14-5.44), elevated serum homocysteine (OR, 1.19; 95% CI, 1.09-1.29), and small-vessel disease subtype (OR, 2.95 95% CI, 1.43-6.10) were all significantly associated with presence of CMB. Logistic regression analysis by number of CMB showed similar findings. Conclusions: Proteinuria is strongly associated with both the frequency and number of CMB in patients with recent cerebral ischemia. Urinary protein excretion may be a CMB risk marker or potential therapeutic target for mitigating the untoward clinical sequela of CMB.