Blood glucose upon return of spontaneous circulation and neurological outcomes following out-of-hospital cardiac arrest.

Background: To elucidate the association between blood glucose levels at the return of spontaneous circulation (ROSC) and neurological outcomes following out-of-hospital cardiac arrest (OHCA), a post hoc analysis was conducted using data from a prospective observational study involving 41 hospitals in Tokyo and its suburbs from 2019 to 2021. Adults with nontraumatic OHCA who achieved ROSC were included. Methods: A total of 1533 patients were analyzed. A spline curve for estimating neurological outcomes (Cerebral Performance Category score ≤2 at 30 days) by blood glucose level at ROSC was generated. Patients were classified into low, moderate, and high blood glucose groups, defined as <100, 100-300, and ≥300 mg/dL, respectively. Neurological outcomes were compared using generalized estimating equations adjusted for patient and institutional characteristics. Results: Favorable neurologic outcomes were fewer in the low and high blood glucose groups than in the moderate group (8/132 [6.1 %] and 62/485 [12.8 %] vs. 181/807 [22.4 %]). The adjusted model revealed that low and high glucose levels at ROSC were associated with fewer favorable outcomes (odds ratios, 0.43 [0.18-0.96] and 0.59 [0.42-0.84]). High blood glucose levels showed unfavorable effects in subgroups with cardiogenic or noncardiogenic etiology, age <65 years, and low-flow time ≤30 min, whereas low blood glucose levels showed unfavorable effects only in cardiogenic cases. Conclusions: Blood glucose levels <100 and ≥300 mg/dL were associated with unfavorable neurological outcomes, with a nonlinear inverted U-shaped relationship.