Effect of diabetes on brain structure: the action to control cardiovascular risk in diabetes MR imaging baseline data.
OBJECTIVE
To investigate the association of characteristics of type 2 diabetes mellitus (duration and biochemical severity of diabetes) to brain structure measured on magnetic resonance (MR) images, specifically testing whether more severity in metrics of diabetes is inversely correlated with brain volumes and positively correlated with ischemic lesion volumes.


METHODS
This study protocol was approved by the institutional review board of each center and participants provided written informed consent. Baseline severity of diabetes was evaluated by testing fasting plasma glucose levels, hemoglobin A1c levels, and duration of diabetes. MR imaging was performed with fluid-attenuated inversion recovery, proton-density, T2-weighted, and T1-weighted sequences, which were postprocessed with an automated computer algorithm that classified brain tissue as gray or white matter and as normal or ischemic. Separate linear regression models adjusted for potential confounding factors were used to investigate the relationship of the diabetes measures to MR imaging outcomes in 614 participants (mean age, 62 years; mean duration of type 2 diabetes mellitus, 9.9 years).


RESULTS
The mean volumes of total gray matter (463.9 cm(3)) and total white matter (463.6 cm(3)) were similar. The mean volume of abnormal tissue was 2.5 cm(3), mostly in the white matter (81% white matter, 5% gray matter, 14% deep gray and white matter). Longer duration of diabetes and higher fasting plasma glucose level were associated with lower normal (β = -0.431 and -0.053, respectively; P < .01) and total gray matter volumes (β = -0.428 and -0.053, respectively; P < .01). Fasting plasma glucose was also inversely correlated with ischemic lesion volume (β = -0.006; P < .04). Hemoglobin A1c level was not associated with any MR imaging measure.


CONCLUSIONS
Longer duration of diabetes is associated with brain volume loss, particularly in the gray matter, possibly reflecting direct neurologic insult; biochemical measures of glycemia were less consistently related to MR imaging changes. Contrary to common clinical belief, in this sample of patients with type 2 diabetes mellitus, there was no association of diabetes characteristics with small vessel ischemic disease in the brain.
From the Department of Radiology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104 (R.N.B., M.B., C.D.); Department of Radiology, Columbia University, New York, NY (R.M.L.); Department of Radiology, Hennepin County Medical Center, Minneapolis, Minn (A.M.); Department of Radiology, Case Western Reserve University, Cleveland, Ohio (K.H.); Department of Radiology, Wake Forest University, Winston-Salem, NC (J.L., M.E.M., J.W.); and National Institute on Aging, Bethesda, Md (L.J.L.).
R Nick
RN
Bryan
Michel
M
Bilello
Christos
C
Davatzikos
Ronald M
RM
Lazar
Anne
A
Murray
Karen
K
Horowitz
James
J
Lovato
Michael E
ME
Miller
Jeff
J
Williamson
Lenore J
LJ
Launer
D000368:Aged; D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis; D001921:Brain / Q000473:pathology*; D002318:Cardiovascular Diseases / Q000473:pathology* / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012720:Severity of Illness Index; D013997:Time Factors
D001786:Blood Glucose