Chronic hyperglycemia is related to poor functional outcome after acute ischemic stroke

Background Acute hyperglycemia is associated with poor functional outcome after ischemic stroke, but the association between chronic antecedent hyperglycemia and outcome is unclear. Aim We assessed the association between chronic hyperglycemia, measured by hemoglobin A1c, and functional outcome in patients with acute ischemic stroke. Methods We included 812 patients with acute ischemic stroke (mean age 66 ± 14 years; 61.5% male). Patients were categorized per hemoglobin A1c level: no (<39 mmol/mol), moderate (39-42 mmol/mol), or severe chronic hyperglycemia (>42 mmol/mol). Poor functional outcome was defined as modified Rankin Scale score > 2 after 3 months. The relation between chronic hyperglycemia and functional outcome was assessed with a Poisson regression analysis and expressed as risk ratios with 95% confidence intervals with no chronic hyperglycemia as the reference. Results Moderate chronic hyperglycemia was present in 234 (28.8%) patients and severe chronic hyperglycemia in 183 (22.5%) patients. Acute hyperglycemia on admission was present in 338 (41.6%) patients. Severe chronic hyperglycemia was associated with poor outcome (risk ratios 1.40; 95% confidence interval 1.09-1.79). After adjustment for age, sex, stroke severity, vascular risk factors, and acute hyperglycemia on admission the risk ratios was 1.35 (95% confidence interval 1.04-1.76). Moderate chronic hyperglycemia was not associated with poor outcome (risk ratios 1.12; 95% confidence interval 0.87-1.44). Conclusion Severe chronic hyperglycemia is associated with poor functional outcome in patients with acute ischemic stroke. This association is independent of hyperglycemia in the acute stage of stroke and of an unfavorable vascular risk factor profile.