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P4‐344: STRUCTURAL CHANGES IN HIPPOCAMPUS OF AGING MEN WITH CEREBRAL ATHEROSCLEROSIS
Author(s) -
Smirnov Alexey Vladimirovich,
Gorelik Elena Vladimirovna,
Guski Hans,
Ekova Maria,
Grigoryeva Natalya Vladimirovna,
Gurov Dmitriy Yu
Publication year - 2019
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2019.06.4014
Subject(s) - hippocampal formation , hippocampus , medicine , pathology , immunohistochemistry , cerebral arteries , vascular dementia , cerebral infarction , ischemia , dementia , disease
Background: Type 2 diabetes mellitus (T2D) is associated with an increased risk of dementia, high blood pressure (BP), increased aortic stiffness, and abnormal haemodynamics. In a sample of older people with T2D, we aimed to study the contribution of these vascular factors to brain structure and cognition, relative to the contribution of other metabolic factors relevant to T2D such as insulin resistance, glycaemic control, and adiposity. Methods: Cross-sectional sample of community dwelling older volunteers with T2D in the Cognition and Diabetes in Older Tasmanians – Blood Pressure (CDOT-BP) study. Measurements included neuropsychological battery, brain magnetic resonance imaging, 24 hour oscillometric measures of central and peripheral BP with pulse wave analysis, and anthropometry. We studied associations of exposure variables with outcomes using structural equation modelling for cognition, and simple linear and logistic regression for brain structural outcomes [white matter integrity, cortical thickness, white matter hyperintensities (WMH), cerebral infarcts]. Standardised coefficients were derived to determine the relative contribution of variables of interest to the outcomes in a combined regression model. Results: There were 202 participants, mean age 68.5 (66.4) years and mean HbA1c1⁄46.42%. Augmentation index was associated with processing speed (p<0.05). BP, aortic stiffness measures, and peripheral nocturnal BP dipping were associated with measures of white matter integrity (fractional anisotropy and mean diffusivity, p<0.05), but not with cortical thickness or WMH. Other T2D-related factors waist hip ratio (WHR, p1⁄40.006), insulin resistance (p1⁄40.002) and the use of both insulin and oral glucose lowering therapy (p1⁄40.004) were also associated with poorer processing speed. The relative contribution of augmentation index to processing speed (standardized b1⁄4-0.237) was greater than those of WHR (b1⁄4-0.175) and use of glucose lowering medications (b1⁄4-0.126), but less than that of age (b1⁄4-0.43). Conclusions: Blood pressure, aortic stiffness and altered haemodynamics contribute to early cognitive change and loss of white matter integrity in T2D. The novel association between nocturnal BP dipping and white matter integrity deserves further investigation. Measures of white matter integrity may be particularly suited to detect the effect of these vascular factors on the brain.