The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy.
It is uncertain whether small vessel disease underlies the relationship between Type 2 Diabetes Mellitus (T2DM) and brain atrophy. We aimed to study whether retinal vascular architecture, as a proxy for cerebral small vessel disease, may modify or mediate the associations of T2DM with brain volumes. In this cross-sectional study using Magnetic Resonance Imaging (MRI) scans and retinal photographs in 451 people with and without T2DM, we measured brain volumes, geometric measures of retinal vascular architecture, clinical retinopathy, and MRI cerebrovascular lesions. There were 270 people with (mean age 67.3 years) and 181 without T2DM (mean age 72.9 years). T2DM was associated with lower gray matter volume (p = 0.008). T2DM was associated with greater arteriolar diameter (p = 0.03) and optimality ratio (p = 0.04), but these associations were attenuated by adjustments for age and sex. Only optimality ratio was associated with lower gray matter volume (p = 0.03). The inclusion of retinal measures in regression models did not attenuate the association of T2DM with gray matter volume. The association of T2DM with lower gray matter volume was independent of retinal vascular architecture and clinical retinopathy. Retinal vascular measures or retinopathy may not be sufficiently sensitive to confirm a microvascular basis for T2DM-related brain atrophy.
Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC 3168, Australia; Department of Neurosciences, Monash Health, Melbourne, VIC 3168, Australia; Aged Care, Alfred Health, Melbourne, VIC 3162, Australia.
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Moran
Melbourne School of Population and Global Health, University of Melbourne, Parkville, VIC 3010, Australia; Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751.
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RJ
Tapp
International Centre for Circulatory Health, National Heart and Lung Institute, St Mary's Hospital and Imperial College, London SW7 2AZ, UK; Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK.
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Hughes
Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia; Research Centre of Applied and Preventative Cardiovascular Medicine, University of Turku, 20700 Turku, Finland.
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Magnussen
Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
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Blizzard
Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC 3168, Australia; Department of Neurosciences, Monash Health, Melbourne, VIC 3168, Australia.
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Phan
Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC 3168, Australia; Developmental Imaging, Murdoch Children's Research Institute, Melbourne, VIC 7000, Australia.
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Beare
International Centre for Circulatory Health, National Heart and Lung Institute, St Mary's Hospital and Imperial College, London SW7 2AZ, UK.
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Witt
Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
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Venn
Department of Pharmacology and Molecular Medicine Research Group, School of Medicine, University of Western Sydney, Campbelltown, NSW 2753, Australia.
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Münch
Royal Victorian Eye and Ear Hospital, Melbourne, VIC 7000, Australia.
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BC
Amaratunge
Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC 3168, Australia; Department of Neurosciences, Monash Health, Melbourne, VIC 3168, Australia; Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
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Srikanth
D000368:Aged; D001284:Atrophy; D059345:Cerebral Small Vessel Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D054022:Cerebrum / Q000000981:diagnostic imaging* / Q000473:pathology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D003930:Diabetic Retinopathy / Q000453:epidemiology; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D013648:Tasmania / Q000453:epidemiology