Abstract
<title>Abstract</title> <p> <italic> <bold>Background:</bold> </italic> <bold/> Whether early in-hospital blood pressure variability (BPV) is associated with acute kidney injury (AKI) after acute ischemic stroke (AIS) is uncertain. In this study, we aimed to examine the association between early diastolic blood pressure (DBP) variability and AKI. <italic> <bold>Methods:</bold> </italic> <bold/> In a single-center retrospective cohort of 2,397 adults hospitalized with AIS (2008–2024), the 72-h coefficient of variation of DBP (DBP-CV) after emergency department arrival was analyzed continuously (per 0.10-unit increase) and by quartiles. AKI was defined via Kidney Disease: Improving Global Outcomes serum creatinine criteria. The primary outcome was any AKI (stages 1–3), and secondary outcomes were stages 2–3 and stage 3 AKI. Logistic regression was adjusted for age, sex, baseline kidney function, mean DBP, hypertension, diabetes mellitus, heart failure, and National Institutes of Health Stroke Scale category. <italic> <bold>Results:</bold> </italic> <bold/> Any AKI occurred in 90 patients (3.8%), stages 2–3 in 40 (1.7%), and stage 3 in 27 (1.1%). The incidence of any AKI rose from 1.2% in Q1 to 7.2% in Q4 ( <italic>p</italic> for trend < 0.001). In the fully adjusted model, each 0.10-unit increase in the DBP-CV was associated with any AKI (adjusted odds ratio [aOR], 1.55; 95% confidence interval [CI], 1.06–2.28; <italic>p</italic> = 0.024); the Q4 versus Q1 DBP-CV conferred higher odds of any AKI (aOR, 3.75; 95% CI, 1.61–8.75; <italic>p</italic> = 0.002). Associations were attenuated after adjusting for the total number of blood pressure measurements and upon restriction of outcomes to events beyond the exposure window. <italic> <bold>Conclusions:</bold> </italic> <bold/> Greater early DBP variability during the first 72 h was independently associated with in-hospital AKI after AIS. The DBP-CV may serve as a clinically accessible marker for AKI risk stratification in this population. </p>