Insulin for Glycemic Control in Acute Ischemic Stroke
Benefits in NNT
None were helped
100% saw no benefit
0% were helped by preventing death or avoiding dependency
Harms in NNT
1 in 7 were harmed (symptomatic hypoglycemic event)
14% were harmed by hypoglycemia
SourceBellolio MF, Gilmore RM, Stead LG. Insulin for glycaemic control in acute ischaemic stroke. Cochrane Database Syst Rev. 2011;(9).
Efficacy EndpointsDeath, disability
Harm EndpointsSymptomatic hypoglycemia
NarrativeHyperglycemia is common after acute ischemic stroke and occurs in up to two-thirds of patients. Clinical trials have concluded that hyperglycemia predicts increased mortality. It is uncertain whether this contributes to brain injury or is merely a physiologic response to acute stroke, and animal studies have suggested that insulin may reduce stroke size by reducing glucose levels, acidosis, and cell injury.
In this 2011 Cochrane review of randomized trials ‘dependence’, a primary outcome, was defined as being severely dependent on others in activities of daily living. Three treatment comparisons were investigated: insulin vs. placebo, low dose insulin vs. high dose insulin, or tight versus liberal glycemic control, all for glucose levels greater >110 mg/dl. This review found no benefit in any comparison.
Seven trials involving 1296 participants were included. Maintaining blood sugar level between 72 and 135 mg/dl immediately after a stroke did not improve outcomes (i.e. did not reduce death or dependence). It did however significantly increase symptomatic hypoglycemic events (confusion, visual disturbances, seizures, sweating, or hunger in a patient with a glucose level lower than 54 mg/dl). The NNH for symptomatic hypoglycemia in the experimental group was 7.