title: Brain glucose concentrations in poorly controlled diabetes mellitus as measured by high-field magnetic resonance spectroscopy.
abstract: Hyperglycemia and diabetes alter the function and metabolism of many tissues. The effect on the brain remains poorly defined, but some animal data suggest that chronic hyperglycemia reduces rates of brain glucose transport and/or metabolism. To address this question in human beings, we measured glucose in the occipital cortex of patients with poorly controlled diabetes and healthy volunteers at the same levels of plasma glucose using proton magnetic resonance spectroscopy. Fourteen patients with poorly controlled diabetes (hemoglobin A 1c = 9.8% +/- 1.7%, mean +/- SD) and 14 healthy volunteers similar with respect to age, sex, and body mass index were studied at a plasma glucose of 300 mg/dL. Brain glucose concentrations of patients with poorly controlled diabetes were lower but not statistically different from those of control subjects (4.7 +/- 0.9 vs 5.3 +/- 1.1 micromol/g wet wt; P = .1). Our sample size gave 80% power to detect a difference as small as 1.1 micromol/g wet wt. We conclude that chronic hyperglycemia in diabetes does not alter brain glucose concentrations in human subjects.
authors.affiliation: Department of Medicine, University of Minnesota Medical School, MN 55455, USA. seaqu001@umn.edu
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Seaquist
authors.forename: Ivan
authors.initials: I
authors.lastname: Tkac
authors.forename: Greg
authors.initials: G
authors.lastname: Damberg
authors.forename: William
authors.initials: W
authors.lastname: Thomas
authors.forename: Rolf
authors.initials: R
authors.lastname: Gruetter
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics*; D015309:Glucose Clamp Technique; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011522:Protons
chemical_list: D005947:Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D011522:Protons