Hyperglycemia as an independent predictor of worse outcome in non-diabetic patients presenting with acute ischemic stroke

Objective: To determine if differences in outcome exist between diabetic and non-diabetic patients who present to the Emergency Department (ED) with acute ischemic stoke (AIS) and elevated blood glucose. Methods: The study population consisted of 447 consecutive patients who presented to the ED with AIS within 24 h of symptom onset and had blood glucose measured on presentation. Hyperglycemia was defined as >130 mg/dl. Outcomes studied included infarct volume, stroke severity (NIH Stroke Scale), functional impairment (modified Rankin Score), and 90-day mortality. Patients with hyperglycemia were then stratified into those with and without a prior history of diabetes mellitus (DM) for the purposes of analysis. Results: Patients with hyperglycemia exhibited significantly greater stroke severity (P = 0.002) and greater functional impairment (P = 0.004) than those with normoglycemia. Patients with hyperglycemia were 2.3 times more likely to be dead at 90 days compared to those with normal glucose (P < 0.001). Stroke severity (P < 0.001) and functional impairment (P < 0.001) were both significantly worse in patients with hyperglycemia and no prior history of DM, when compared to patients with hyperglycemia and previously diagnosed DM. Among the patients without a prior history of DM, patients with hyperglycemia were 3.4 times more likely to die within 90 days (P < 0.001) when compared with patients with normoglycemia. In contrast, the hazard ratio was 1.6 among the patients with DM (P = 0.66). Conclusion: Hyperglycemia on presentation is associated with significantly poorer outcomes following AIS. Patients with hyperglycemia and no prior history of DM have a particularly poor prognosis, worse than that for patients with known diabetes and hyperglycemia.