Elevated glycated hemoglobin level and hyperglycemia after aneurysmal subarachnoid hemorrhage

Elevated blood glucose is frequently detected early after aneurysmal subarachnoid hemorrhage (aSAH) and is considered a risk factor for poor neurological outcome. However it remains unclear whether hyperglycemia is caused by the SAH ictus or reflects a pre-existing hyperglycemic metabolism. In a prospective register we analysed glycated haemoglobin levels (HbA1c) in patients with aSAH and its influence on outcome.

Between July 2012 and July 2014, 87 patients with confirmed aSAH were included (NCT02081820). Within 72h HbA1c levels were assessed as a measure for hyperglycemic metabolism preceding aSAH. Blood glucose levels were recorded upon admission. Patient outcome was recorded after 6 months using modified Rankin scale (mRS).

HbA1c levels did not correlate with initial neurological status (p=0.338, r=0.104). On the contrary, initial blood glucose levels correlated significantly with neurological status at admission (p=0.001, r=0.341). Additionally, HbA1c levels failed to show a significant influence on the occurrence of delayed cerebral ischemia (DCI) (p=0.400) or outcome after 6 months (p=0.790).

A pre-existing hyperglycemic metabolism does not contribute to the severity of aSAH or influences the quality of neurological recovery. Hyperglycemia after aSAH correlates with initial neurological status and patient outcome and is potentially attributable to the metabolic changes induced by the brain injury after the hemorrhage.