Glucose control using a closed-loop device decreases inflammation after cardiovascular surgery without increasing hypoglycemia risk

Although tight glucose control might reduce inflammation after cardiac surgery, it remains unclear whether inflammation can be controlled by maintaining glucose levels within 110–180 mg/dL. We hypothesized that a glucose target range of 110–180 mg/dL decreases inflammation after cardiovascular surgery. This retrospective study included 72 cardiovascular surgery patients divided into two groups according to the glucose control approach. Patients allocated to the closed-loop group received closed-loop glucose control (target glucose levels at 110–180 mg/dL) from admission to the intensive care unit until 9 a.m. on postoperative day (POD) 1. Patients allocated to the conventional group received conventional glucose control using a sliding scale method to maintain blood glucose levels < 200 mg/dL. Primary outcomes were C-reactive protein (CRP) levels on PODs 1, 2, and 7. Data were reported as mean ± standard deviation. Comparisons were performed using the chi-squared test and unpaired t test, with p < 0.05 indicating statistical significance. The closed-loop group had significantly lower average glucose levels (169 ± 24 vs. 201 ± 36 mg/dL, p < 0.001) and standard deviation of glucose levels (22 ± 13 vs. 44 ± 20 mg/dL; p < 0.001). The CRP levels on PODs 2 and 7 were significantly lower in the closed-loop group than in the conventional group (10.8 ± 5.6 vs. 14.1 ± 5.7 mg/dL, p = 0.02; 4.6 ± 2.5 vs. 7.3 ± 4.0 mg/dL, p < 0.001; respectively). Our findings suggest that glucose control using a closed-loop device might decrease inflammation after cardiovascular surgery without increasing hypoglycemia risk.