Controlling high blood sugar levels with insulin in people who have had an acute ischaemic stroke

After a stroke, people with high levels of sugar in their blood have increased mortality regardless of their age, how severe the stroke was, or what type of stroke they had. Insulin can reduce blood sugar levels. We do not know what the optimal level of blood sugar should be after a stroke. We searched for trials that compared usual care with intensive insulin treatment (trying to keep blood sugar levels within the normal range of 4 to 7.5 mmol/L) after stroke. We found 11 trials involving 1583 participants. Trying to keep the blood sugar level within a tight range immediately after a stroke did not improve the outcomes of neurological deficit and dependency. It did, however, significantly increase the chance of experiencing very low blood sugar levels (hypoglycaemia), which can be harmful and can cause brain damage and death. On balance, the trials did not show any benefit from intensive control of blood sugar levels after stroke.

Authors' conclusions: 

After updating the results of our previous review, we found that the administration of intravenous insulin with the objective of maintaining serum glucose within a specific range in the first hours of acute ischaemic stroke does not provide benefit in terms of functional outcome, death, or improvement in final neurological deficit and significantly increased the number of hypoglycaemic episodes. Specifically, those people whose glucose levels were maintained within a tighter range with intravenous insulin experienced a greater risk of symptomatic and asymptomatic hypoglycaemia than those people in the control group.

Read the full abstract...

People with hyperglycaemia concomitant with an acute stroke have greater mortality, stroke severity, and functional impairment when compared with those with normoglycaemia at stroke presentation. This is an update of a Cochrane Review first published in 2011.


To determine whether intensively monitoring insulin therapy aimed at maintaining serum glucose within a specific normal range (4 to 7.5 mmol/L) in the first 24 hours of acute ischaemic stroke influences outcome.

Search strategy: 

We searched the Cochrane Stroke Group Trials Register (September 2013), CENTRAL (The Cochrane Library 2013, Issue 8), MEDLINE (1950 to September 2013), EMBASE (1980 to September 2013), CINAHL (1982 to September 2013), Science Citation Index (1900 to September 2013), and Web of Science (ISI Web of Knowledge) (1993 to September 2013). We also searched ongoing trials registers and SCOPUS.

Selection criteria: 

Randomised controlled trials (RCTs) comparing intensively monitored insulin therapy versus usual care in adults with acute ischaemic stroke.

Data collection and analysis: 

We obtained a total of 1565 titles through the literature search. Two review authors independently selected the included articles and extracted the study characteristics, study quality, and data to estimate the odds ratio (OR) and 95% confidence interval (CI), mean difference (MD) and standardised mean difference (SMD) of outcome measures. We resolved disagreements by discussion.

Main results: 

We included 11 RCTs involving 1583 participants (791 participants in the intervention group and 792 in the control group). We found that there was no difference between the treatment and control groups in the outcomes of death or dependency (OR 0.99, 95% CI 0.79 to 1.23) or final neurological deficit (SMD -0.09, 95% CI -0.19 to 0.01). The rate of symptomatic hypoglycaemia was higher in the intervention group (OR 14.6, 95% CI 6.6 to 32.2). In the subgroup analyses of diabetes mellitus (DM) versus non-DM, we found no difference for the outcomes of death and disability or neurological deficit. The number needed to treat was not significant for the outcomes of death and final neurological deficit. The number needed to harm was nine for symptomatic hypoglycaemia.