Prognostic Significance of Admission Blood Glucose for 30-Day Survival and Neurological Outcomes in Non-Diabetic Out-of-Hospital Cardiac Arrest Patients: A Retrospective Cohort Study

Objective: To investigate the association between admission blood glucose (BG) and 30-day survival and neurological outcomes in adult, non-diabetic out-of-hospital cardiac arrest (OHCA) patients with return of spontaneous circulation (ROSC). Methods: We conducted a single-center retrospective cohort study (2014-2023) including 1,128 non-diabetic adults with OHCA who achieved ROSC. Patients were stratified by admission BG into four categories: <80 mg/dL, 80-179 mg/dL, 180-299 mg/dL, and ≥300 mg/dL. Primary outcomes were 30-day survival and favorable neurological status (Cerebral Performance Category [CPC] 1-2). Multivariable logistic regression models adjusted for major confounders (age, sex, initial rhythm, bystander CPR, call-to-arrival time, and extracorporeal CPR) using the 80-179 mg/dL group as the reference. Restricted cubic spline analyses explored potential nonlinear relationships between BG and outcomes. Results: Patients with mild-to-moderate hyperglycemia (180-299 mg/dL) demonstrated the highest 30-day survival (14.7%) and favorable neurological outcome (10.8%) rates, compared with hypoglycemia (6.6% and 4.7%; both p < 0.05). In adjusted analyses, hypoglycemia (<80 mg/dL) and severe hyperglycemia (≥300 mg/dL) were associated with significantly lower odds of survival (adjusted odds ratio [aOR] = 0.41, 95% CI 0.21-0.79; and aOR = 0.69, 95% CI 0.52-0.91, respectively). Spline analysis revealed a U-shaped association, with optimal survival observed at 140-195 mg/dL. Conclusion: Admission BG is an easily measurable prognostic biomarker in non-diabetic OHCA. Mild-to-moderate hyperglycemia was associated with the most favorable short-term outcomes, whereas both hypoglycemia and severe hyperglycemia predicted worse survival and neurological recovery.