The optimal blood glucose is significantly associated with lower mortality in critically ill patients with cardiogenic shock: an analysis revealed with time series blood glucose records

Abstract

Abstract Background The optimal blood glucose (BG) level for patients with cardiogenic shock in the intensive care unit (ICU) remains unclear. Studies have found that both excessively high and low BG levels contribute to adverse cardiovascular events. Our study aims to investigate the optimal BG level for critically ill patients with cardiogenic shock and evaluate the effects of optimal BG on the prognosis of patients. Methods A total of 2013 patients with cardiogenic shock obtained from the Medical Information Mart for Intensive Care (MIMIC) IV database were included in the final cohort for our retrospective observational study for data analysis. The exposure was time-weighted average BG (TWA-BG), which was calculated by the time-series BG records and corresponding time stamps of patients with cardiogenic shock during their stay in the ICU. The cut-off value of TWA-BG was identified by the restricted cubic spline curve and included patients were categorized into three groups: low TWA-BG group (TWA-BG ≤ 104 mg/dl), optimal TWA-BG group (104 < TWA-BG ≤ 138 mg/dl), and high TWA-BG group (TWA-BG > 138 mg/dl). The primary outcome was 28-day mortality, and the secondary outcomes were ICU and in-hospital mortality. We performed the log-rank test to detect whether there is a difference in mortality among different groups in the original cohort. Multiple distinct models were employed to validate the robustness of the results. Results Our study revealed that the optimal BG level for critically ill patients with cardiogenic shock is 104–138 mg/dl. Compared to the optimal TWA-BG group, the low TWA-BG group (hazard ratio (HR): 1.67, 95% confidence interval (CI): 1.19–2.33, p = 0.002) and high TWA-BG group (HR: 1.72, 95% CI: 1.46–2.03, p < 0.001) exhibited higher 28-day mortality. Similarly, the low TWA-BG group and high TWA-BG group demonstrated higher risks in terms of ICU mortality (low TWA-BG group: HR: 2.30, 95% CI: 1.40–3.79, p < 0.001; high TWA-BG group: HR: 1.77, 95% CI: 1.45–2.17, p < 0.001) and in-hospital mortality (low TWA-BG group: HR: 1.73, 95% CI: 1.19–2.51, p = 0.001; high TWA-BG group: HR: 1.64, 95% CI: 1.38–1.95, p < 0.001). Sensitivity analysis conducted through propensity score matching and the subgroup analysis further substantiated the robustness of the results. Conclusion The optimal BG level for patients with cardiogenic shock is 104–138 mg/dl. BG levels below 104 mg/dl and above 138 mg/dl were associated with a less favorable prognosis.