Intravenous Insulin Therapy in the Maintenance of Strict Glycemic Control in Nondiabetic Acute Stroke Patients With Mild Hyperglycemia

Several reports indicate that mild hyperglycemia (plasma glucose level [PGL] ≥7.0 and ≤10.0 mmol/L [≥126 and ≤180 mg/dL]) is associated with poor prognosis in nondiabetic patients who sustain acute ischemic stroke (AIS). Insulin therapy to maintain PGL <7.0 mmol/L (<126 mg/dL) has been reported to be beneficial in critically ill patients, but the safety and efficacy of this approach in patients with AIS are not well established. In a prospective, open-label study, 50 consecutive nondiabetic patients with AIS admitted within 12 hours of ictus and with a PGL ≥7.0 and ≤10.0 mmol/L (≥126 and ≤180 mg/dL) were randomized to receive either a 24-hour intravenous (IV) insulin infusion (ISI) adjusted to maintain PGL within 4.5-7.0 mmol/L (81-126 mg/dL) (ISI group; n = 26) or treatment with subcutaneous insulin if PGL was >10.0 mmol/L (>180 mg/dL) (control group [CG]; n = 24). Patients' neurologic status was assessed based on National Institutes of Health Stroke Scale (NIHSS) score at admission, 24 hours and 30 days. The 2 groups did not differ in terms of risk factors for stroke. The mean PGL measured at admission was 8.25 ± 0.9 mmol/L (149 ± 16 mg/dL) in the ISI group and 8.1 ± 0.8 mmol/L (146 ± 14 mg/dL) in the CG (P = .8). After 24 hours, these values dropped to 4.9 ± 0.5 mmol/L (88 ± 9 mg/dL) and 5.5 ± 0.45 mmol/L (99 ± 8 mg/dL), respectively (P < .01). Two patients from the ISI group (8%) required IV glucose infusion for symptomatic hypoglycemia. There was no significant between-group difference in neurologic status at admission (median NIHSS score, 10 ± 3 vs 10 ± 2) and 24 hours later (8 ± 2 vs 9 ± 3). At 30 days, the median NIHSS score was 4 ± 3 in the ISI group and 7 ± 4 in the CG (P = .04). Our findings indicate that in nondiabetic AIS patients with mild hyperglycemia, IV insulin therapy aimed at maintaining strict glycemic control (PGL 4.5-7.0 mmol/L [81-126 mg/dL]) is relatively safe and may improve stroke outcome.