Relationships between hyperglycemia and cognitive performance among adults with type 1 and type 2 diabetes.
OBJECTIVE
Hyperglycemia is a common event among patients with type 1 and type 2 diabetes. While the cognitive-motor slowing associated with hypoglycemia is well documented, the acute effects of hyperglycemia have not been studied extensively, despite patients' reports of negative effects. This study prospectively and objectively assessed the effects of hyperglycemia on cognitive-motor functioning in subjects' natural environment.


METHODS
Study 1 investigated 105 adults with type 1 diabetes (mean age 37 years and mean duration of diabetes 20 years), study 2 investigated 36 adults with type 2 diabetes (mean age 50 years and mean duration of diabetes 10 years), and study 3 investigated 91 adults with type 1 diabetes (mean age 39 years and mean duration of diabetes 20 years). Subjects used a hand-held computer for 70 trials over 4 weeks, which required them to complete various cognitive-motor tasks and then measure and enter their current blood glucose reading.


RESULTS
Hyperglycemia (blood glucose >15 mmol/l) was associated with slowing of all cognitive performance tests (P < 0.02) and an increased number of mental subtraction errors for both type 1 and type 2 diabetic subjects. The effects of hyperglycemia were highly individualized, impacting approximately 50% of the subjects.


CONCLUSIONS
Acute hyperglycemia is not a benign event for many individuals with diabetes, but it is associated with mild cognitive dysfunction.
Cox
Daniel J
DJ
Center for Behavioral Medicine Research, University of Virginia Health System, Charlottesville, Virginia 22908, USA. djc4f@virginia.edu
Kovatchev
Boris P
BP
Gonder-Frederick
Linda A
LA
Summers
Kent H
KH
McCall
Anthony
A
Grimm
Kevin J
KJ
Clarke
William L
WL
D000328:Adult; D017668:Age of Onset; D001364:Awareness; D001786:Blood Glucose / Q000378:metabolism*; D003071:Cognition / Q000502:physiology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000523:psychology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000523:psychology*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000523:psychology*; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D008875:Middle Aged; D011597:Psychomotor Performance
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin