Structural and functional brain changes in middle-aged type 2 diabetic patients: a cross-sectional study.
BACKGROUND
Type 2 diabetes mellitus (T2DM) is an emerging risk factor for cognitive impairment. Whether this impairment is a direct effect of this metabolic disorder on brain function, a consequence of vascular disease, or both, remains unknown. Structural and functional neuroimaging studies in patients with T2DM could help to elucidate this question.


OBJECTIVE
We designed a cross-sectional study comparing 25 T2DM patients with 25 age- and gender-matched healthy control participants. Clinical information, APOE genotype, lipid and glucose analysis, structural cerebral magnetic resonance imaging including voxel-based morphometry, and F-18 fluorodeoxyglucose positron emission tomography were obtained in all subjects.


METHODS
Gray matter densities and metabolic differences between groups were analyzed using statistical parametric mapping. In addition to comparing the neuroimaging profiles of both groups, we correlated neuroimaging findings with HbA1c levels, duration of T2DM, and insulin resistance measurement (HOMA-IR) in the diabetic patients group.


RESULTS
Patients with T2DM presented reduced gray matter densities and reduced cerebral glucose metabolism in several fronto-temporal brain regions after controlling for various vascular risk factors. Furthermore, within the T2DM group, longer disease duration, and higher HbA1c levels and HOMA-IR were associated with lower gray matter density and reduced cerebral glucose metabolism in fronto-temporal regions.


CONCLUSIONS
In agreement with previous reports, our findings indicate that T2DM leads to structural and metabolic abnormalities in fronto-temporal areas. Furthermore, they suggest that these abnormalities are not entirely explained by the role of T2DM as a cardiovascular risk factor.
Department of Medicine, Faculty of Medicine, University of Malaga, Spain Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
Natalia
N
García-Casares
Department of Medicine, Faculty of Medicine, University of Malaga, Spain Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
Marcelo L
ML
Berthier
Department of Psychiatry, Iowa City Veterans Administration Medical Center, The University of Iowa, West Iowa City, IA, USA.
Ricardo E
RE
Jorge
Department of Neurology, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
Pedro
P
Gonzalez-Alegre
Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
Antonio
A
Gutiérrez Cardo
Department of Medicine, Faculty of Medicine, University of Malaga, Spain Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
José
J
Rioja Villodres
The Iowa Consortium for Substance Abuse Research and Evaluation, The University of Iowa, Iowa City, IA, USA.
Laura
L
Acion
Department of Medicine, Faculty of Medicine, University of Malaga, Spain Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
María José
MJ
Ariza Corbo
Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain.
Alejandro
A
Nabrozidis
Department of Endocrinology, Carlos-Haya Hospital, Malaga, Spain.
Juan A
JA
García-Arnés
Department of Medicine, Faculty of Medicine, University of Malaga, Spain Centro de Investigaciones Médico-Sanitarias (C.I.M.E.S), Malaga, Spain Department of Internal Medicine, University Hospital Virgen de la Victoria, Malaga, Spain.
Pedro
P
González-Santos
D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics; D001794:Blood Pressure; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000209:etiology / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography
D001057:Apolipoproteins E; D019788:Fluorodeoxyglucose F18
cognition; magnetic resonance imaging; neuroimaging; positron emission tomography; type 2 diabetes mellitus