Pre-Stroke Loop Diuretics and Anemia in Elderly Patients Are Associated Factors of Severe Renal Dysfunction at the Time of Acute Stroke Onset

Background: Severe renal dysfunction (SRD), an advanced stage of chronic kidney disease (CKD), can limit the treatment options for acute stroke (AS) patients. Therefore, it is important to investigate the associated factors of SRD in AS patients to inhibit CKD progression to SRD before AS. Sex differences exist in the renal function. Therefore, we investigated the frequency of SRD and its associated factors among AS patients by sex. Methods: Our cross-sectional study included patients admitted within 24 h of AS onset between 2013 and 2019 with available pre-stroke medication information. We used the Cockcroft–Gault equation for calculating the creatinine clearance (Ccr) and defined SRD as a Ccr < 30 mL/min. We performed multivariable logistic regression analysis to identify the independent factors associated with SRD. Results: Out of 4294 patients, 3472 matched our criteria. Of these, 1905 (54.9%) were male, with median ages of 75 and 81 years for males and females, respectively. The frequency of SRD was 9.7% in males and 18.7% in females. Loop diuretics and anemia were associated factors of SRD. Conclusions: Pre-stroke loop diuretics and anemia in elderly patients were associated factors of SRD in both sexes. Individualized drug therapy and anemia management are essential to prevent SRD.