Effects of admission hyperglycemia on mortality and costs in acute ischemic stroke

Abstract

BACKGROUND: Hyperglycemia at the time of acute ischemic stroke has been linked to worse outcome in both human and animal studies. OBJECTIVE: To describe the prevalence and severity of hyperglycemia on hospital admission among acute ischemic stroke patients, to examine the independent relationship of admission hyperglycemia to all-cause mortality, and to document the inpatient management of hyperglycemia. METHODS: Patients hospitalized with acute ischemic stroke at one hospital from July 1993 to June 1998 (n = 656) were identified. Demographic data, diagnoses, and blood glucose (BG) values were retrieved from the electronic medical record system. Admission stroke severity, fingerstick BG results, and new diabetes diagnoses were obtained by chart review. Hyperglycemia was defined as admitting random serum BG > or = 130 mg/dL. Hazard ratios (HR) for 30-day, 1-year, and 6-year mortality were calculated using multivariable Cox regression models. RESULTS: Hyperglycemia at admission to hospital was present in 40% of patients with acute stroke. Patients with hyperglycemia were more often women and more likely to have prior diagnoses of diabetes and heart failure. Almost all of these patients remained hyperglycemic during their hospital stay (mean BG = 206 mg/dL), and 43% received no inpatient hypoglycemic drugs. Hyperglycemic patients had longer hospital stay (7 vs 6 days, p = 0.015) and higher inpatient hospital charges ($6,611 vs $5,262, p < 0.001). Hyperglycemia independently increased the risk for death at 30 days (HR 1.87, p < or = 0.01), 1 year (HR 1.75, p < or = 0.01), and 6 years after stroke (HR 1.41, p </= 0.01). CONCLUSIONS: Admitting hyperglycemia was common among patients with acute ischemic stroke and was associated with increased short- and long-term mortality and with increased inpatient charges. Inpatient blood glucose management was suboptimal in this hospital. A trial of intensive treatment of hyperglycemia should be considered.