Insulin resistance accounts for metabolic syndrome-related alterations in brain structure

• Main Authors: Aziz, N.A (Author), Breteler, M.M.B (Author), Diers, K. (Author), Lu, R. (Author), Reuter, M. (Author), Stöcker, T. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adult; Adult; aged; Aged; Article; atrophy; brain cortex; Cerebral Cortex; cohort analysis; cortical thickness; cortical thickness (brain); diagnostic imaging; female; Female; gray matter; Gray Matter; gray matter volume; human; Humans; image reconstruction; image segmentation; insulin resistance; Insulin Resistance; magnetic resonance imaging; Magnetic Resonance Imaging; major clinical study; male; Male; metabolic syndrome; Metabolic Syndrome; metabolic syndrome X; middle aged; Middle Aged; morphometry; neuropathology; nuclear magnetic resonance imaging; pathology; physiology; priority journal; statistical model; white matter; White Matter
• Online Access: View Fulltext in Publisher

 Metabolic syndrome (MetS) is a major public health burden worldwide and associated with brain abnormalities. Although insulin resistance is considered a pivotal feature of MetS, its role in the pathogenesis of MetS-related brain alterations in the general population is unclear. Therefore, in 973 participants (mean age 52.5 years) of the population-based Rhineland Study, we assessed brain morphology in relation to MetS and insulin resistance, and evaluated to what extent the pattern of structural brain changes seen in MetS overlap with those associated with insulin resistance. Cortical reconstruction and volumetric segmentation were obtained from high-resolution brain images at 3 Tesla using FreeSurfer. The relations between metabolic measures and brain structure were assessed through (generalized) linear models. Both MetS and insulin resistance were associated with smaller cortical gray matter volume and thickness, but not with white matter or subcortical gray matter volume. Age- and sex-adjusted vertex-based brain morphometry demonstrated that MetS and insulin resistance were related to cortical thinning in a similar spatial pattern. Importantly, no independent effect of MetS on cortical gray matter was observed beyond the effect of insulin resistance. Our findings suggest that addressing insulin resistance is critical in the prevention of MetS-related brain changes in later life. © 2021 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.