The role of hyperglycemia in the outcome of intracerebral hemorrhage: A causative analysis

Background Hyperglycemia in the acute phase of intracerebral hemorrhage (ICH) has been associated with poor functional outcomes, however all interventions to lower glucose have yielded neutral or negative results. We attempt an explanation of the causal role of hyperglycemia in ΙCH outcome using generalized structural equation modeling. Materials and methods Consecutive primary ICH patients admitted to an academic hospital between 2007 and 2018 were identified. Patients with missing baseline or follow up CT scans and without 90 day follow up status were excluded. We constructed a causal model accounting for pre-defined markers of ICH severity to evaluate the association between mean 72 h glucose and 90 day functional outcome measured by modified Rankin Scale, dichotomized as favorable ≤2 or unfavorable >2. Results Primary analyses included 410 patients (70.4 ± 13.8years, 43 % female). Mean 72 h glucose was 137.5 ± 33.4mg/dl and 102 (25 %) patients were diabetic. On univariable analysis, higher glucose levels were negatively correlated with favorable outcome (p < 0.0001). However in the structural equation model, this relationship was significantly attenuated (p = 0.06) after accounting for the causal effect of diabetes (p < 0.0001), hematoma volume (p < 0.0001), intraventricular extension (p = 0.01) and Glasgow coma scale (p = 0.001) on glucose levels. On secondary analyses stratifying by diagnosis of diabetes, higher glucose levels were negatively correlated with favorable outcome in patients without diabetes (p = 0.04), but not in patients with diabetes (p = 0.35). Conclusions Hyperglycemia may be a downstream effect of other markers of ICH severity, particularly among patients without diabetes, suggesting a possible explanation for the limited evidence of glucose lowering interventions in outcome.