My daughter’s school would like to see some studies on the extent of cognitive thinking impairment when blood sugars are out of the normal range. In other words, what degree of impairment is found at differing blood sugar levels? As a pharmacist, I am also interested in review that information but I have not been able to find it.

There is not much specific information related to specific blood glucose levels. Best cognitive research comes from Professor Eugen Schoenle and his colleagues in Zurich at the Kinderspital. If you do a PubMed (U.S. National Library of Medicine National Institutes of Health) web site, search under his name, you will see their published reports. In general, advice is not to take tests when blood glucose levels are below 60 mg/dl [3.3 mmol/L] or if someone is symptomatic/hypoglycemic. There is no known cut off point for hyperglycemia, however.

SB

[Editor’s comment: For related information, see Hypoglycaemia and Cognitive Function; Relationships between hyperglycemia and cognitive performance among adults with type 1 and type 2 diabetes; Neurocognitive correlates of type 1 diabetes mellitus in childhood; The effects of glucose fluctuation on cognitive function and QOL: the functional costs of hypoglycaemia and hyperglycaemia among adults with type 1 or type 2 diabetes; Acute hyperglycaemia impairs cognitive function in children with IDDM; Cognitive Function is Disrupted by Both Hypo- and Hyperglycemia in School-Aged Children with type 1 diabetes: A Field Study; and Effects of prior hypoglycemia and hyperglycemia on cognition in children with type 1 diabetes mellitus.

BH]