Metabolic and vascular determinants of impaired cognitive performance and abnormalities on brain magnetic resonance imaging in patients with type 2 diabetes.
OBJECTIVE
The determinants of cerebral complications of type 2 diabetes are unclear. The present study aimed to identify metabolic and vascular factors that are associated with impaired cognitive performance and abnormalities on brain MRI in patients with type 2 diabetes.


METHODS
The study included 122 patients and 56 controls. Neuropsychological test scores were divided into five cognitive domains and expressed as standardised z values. Brain MRI scans were rated for white matter lesions (WML), cortical and subcortical atrophy, and infarcts. Data on glucose metabolism, vascular risk factors and micro- and macrovascular disease were collected.


RESULTS
Patients with type 2 diabetes had more cortical (p < 0.001) and subcortical (p < 0.01) atrophy and deep WML (p = 0.02) than the control group and their cognitive performance was worse. In multivariate regression analyses within the type 2 diabetes group, hypertension (p < 0.05) and a history of vascular events (p < 0.01) were associated with worse cognitive performance, while statin use was associated (p < 0.05) with better performance. Retinopathy and brain infarcts on MRI were associated with more severe cortical atrophy (both p < 0.01) and statin use with less atrophy (p < 0.05). Insulin level and brain infarcts were associated with more severe WML and statin use with less severe WML (all p < 0.05).


CONCLUSIONS
Type 2 diabetes is associated with modest impairments in cognition, as well as atrophy and vascular lesions on MRI. This 'diabetic encephalopathy' is a multifactorial condition, for which atherosclerotic (macroangiopathic) vascular disease is an important determinant. Chronic hyperglycaemia, hyperinsulinaemia and hypertension may play additional roles.
Manschot
S M
SM
Rudolf Magnus Institute of Neuroscience, Department of Neurology, G03.228, University Medical Center, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. S.M.Manschot@umcutrecht.nl
Biessels
G J
GJ
de Valk
H
H
Algra
A
A
Rutten
G E H M
GE
van der Grond
J
J
Kappelle
L J
LJ
D000368:Aged; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology* / Q000503:physiopathology / Q000523:psychology; D003925:Diabetic Angiopathies / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D003929:Diabetic Neuropathies / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012016:Reference Values