Association between hemoglobin A₁C levels and clinical outcome in ischemic stroke patients with or without diabetes.

Individuals with diabetes are at a higher risk of suffering stroke, but whether chronic hyperglycemia affects clinical outcomes after stroke is unclear. We examined whether chronic hyperglycemia, measured in terms of hemoglobin A1C (HbA₁C) levels, influences clinical outcomes after acute ischemic stroke. We prospectively and consecutively included patients admitted within 7 days of ischemic stroke onset. Demographic and clinical information and outcomes were analyzed separately for patients with or without diabetes in order to identify associations with HbA₁C tercile. A total of 1351 patients without diabetes and 526 with diabetes were included. The risk of mortality and poor outcome showed a tendency to increase with increasing HbA₁C tercile in both groups. Rates of mortality and poor outcome were significantly higher in the third tercile than in the first tercile. In contrast, rates of mortality and poor outcome in the second tercile were not significantly different from those in the first tercile. The adjusted odds ratios of poor outcome and mortality increased with increasing tercile of HbA₁C both in patients with diabetes and in patients without diabetes, and these relationships were independent of other confounders. Kaplan-Meier estimates of cumulative mortality also increased with increasing HbA₁C in both groups of patients (with diabetes, p=0.034; without diabetes, p=0.025). Our results suggest that elevated HbA₁C is associated with risk of poor outcome and mortality in ischemic stroke patients with or without diabetes.