Prognostic significance of diabetes and stress hyperglycemia in acute stroke patients

Background Hyperglycemic non-diabetic stroke patients have a worse prognosis than both normoglycemic and diabetic patients. Aim of this study was to assess whether hyperglycemia is an aggravating factor or just an epiphenomenon of most severe strokes. Methods In this retrospective study, 1219 ischemic or hemorrhagic stroke patients (73.7 +/- 13.1 years) were divided into 4 groups: 0 = non-hyperglycemic non-diabetic, 1 = hyperglycemic non-diabetic, 2 = non-hyperglycemic diabetic and 3 = hyperglycemic diabetic. Hyperglycemia was defined as fasting blood glucose >= 126 mg/dl (>= 7 mmol/l) measured the morning after admission, while the diagnosis of diabetes was based on a history of diabetes mellitus or on a glycated hemoglobin >= 6.5% (>= 48 mmol/mol), independently of blood glucose levels. All diabetic patients, except 3, had Type 2 diabetes. The 4 groups were compared according to clinical history, stroke severity indicators, acute phase markers and main short term stroke outcomes (modified Rankin scale >= 3, death, cerebral edema, hemorrhagic transformation of ischemic lesions, fever, oxygen administration, pneumonia, sepsis, urinary infection and heart failure). Results Group 1 patients had more severe strokes, with larger cerebral lesions and higher inflammatory markers, compared to the other groups. They also had a high prevalence of atrial fibrillation, prediabetes, previous stroke and previous arterial revascularizations. In this group, the highest frequencies of cerebral edema, hemorrhagic transformation, pneumonia and oxygen administration were obtained. The prevalence of dependency at discharge and in-hospital mortality were equally high in Group 1 and Group 3. However, in multivariate analyses including stroke severity, cerebral lesion diameter, leukocytes and C-reactive protein, Group 1 was only independently associated with hemorrhagic transformation (OR 2.01, 95% CI 0.99-4.07), while Group 3 was independently associated with mortality (OR 2.19, 95% CI 1.32-3.64) and disability (OR 1.70, 95% CI 1.01-2.88). Conclusions Hyperglycemic non-diabetic stroke patients had a worse prognosis than non-hyperglycemic or diabetic patients, but this group was not independently associated with mortality or disability when size, severity and inflammatory component of the stroke were accounted for.