Differential impact of chronic kidney disease on the risk of ischemic versus hemorrhagic stroke: a nationwide population-based cohort study

Chronic kidney disease (CKD) is associated with increased stroke risk; however, how stroke risk differs by subtype and CKD severity remains incompletely understood. This study aimed to evaluate the association between CKD and the risk of acute stroke, with specific focus on ischemic and hemorrhagic subtypes. This study is a nationwide population-based retrospective cohort study with follow-up from January 1, 2014, through December 31, 2023. CKD status was defined at baseline (2012–2013) and treated as a fixed exposure throughout follow-up, with 2009–2013 serving as a washout period. The final cohort included 9,905,443 adults. CKD was defined as an eGFR < 60 mL/min/1.73 m² or the presence of relevant diagnostic codes recorded as the primary or secondary diagnosis during outpatient visits in the baseline period. Incident acute stroke requiring hospitalization with neuroimaging, including ischemic and hemorrhagic stroke subtypes. CKD was associated with a higher risk of acute stroke (adjusted hazard ratio [aHR], 1.36; 95% confidence interval [CI], 1.32–1.41), including hemorrhagic (aHR, 1.29; 95% CI, 1.20–1.39) and ischemic stroke (aHR, 1.38; 95% CI, 1.33–1.43). For ischemic stroke, the risk increased among participants with mild to moderate CKD (aHR, 1.37; 95% CI, 1.32–1.43) and showed a small increase in risk among those with advanced CKD (aHR, 1.44; 95% CI, 1.30–1.59). In contrast, the risk of hemorrhagic stroke exhibited a disproportionate surge in advanced CKD (aHR, 2.04; 95% CI, 1.74–2.38) compared with mild to moderate CKD (aHR, 1.19; 95% CI, 1.10–1.29). In this nationwide cohort, CKD was associated with higher risks of ischemic and hemorrhagic stroke, with distinct severity-dependent trajectories, particularly a disproportionate surge in hemorrhagic stroke risk at the advanced CKD stage. These findings support subtype-specific and severity-stratified approaches to stroke prevention in patients with CKD. Not applicable.