Aim: To investigate the longitudinal changes in brain volume and cognitive function associated with diabetes at midlife, and to examine whether long-term hyperglycaemia, insulin resistance or secretory function is associated with brain atrophy and cognitive decline. Materials and Methods: We used data from 2377 participants with both baseline and 4-year follow-up brain magnetic resonance images and neuropsychological measures from the Ansan cohort of the Korean Genome Epidemiology Study. Time-weighted mean glycaemic values were calculated using all measurements over an average duration of 10.6 years from cohort initiation to baseline visits. Results: Type 2 diabetes was associated with greater white matter volume reduction (adjusted volume difference = −1.96 ml, 95% CI: −3.73, −0.18) and executive function decline (adjusted Z score difference = −0.14, 95% CI: −0.23, −0.05) during the follow-up period of 4.2 years. Decline of verbal and visual memory or verbal fluency was not associated with diabetes. Greater executive function decline was associated with higher time-weighted mean HbA1c level over the preceding 10.6 years (P <.001), but not with insulin resistance markers in the diabetes group. Participants with diabetes, whose time-weighted average HbA1c level was maintained above 6.5% over the previous decade, showed greater decline in executive function and global cognition than the normal glucose group. Conclusions: Long-term hyperglycaemia was a major independent factor associated with rapid cognitive decline in middle-aged adults with diabetes. Maintaining ideal glucose levels in diabetes at midlife might prevent later rapid cognitive decline.
Bibliographical noteFunding Information:
This workwas supported by funds from the Korean Centers for Disease Control and Prevention (2011‐E71004‐00, 2012‐E71005‐00, 2013‐E71005‐00, 2014‐E71003‐00, 2015‐P71001‐00, 2016‐E71003‐00, 2017‐E71001‐00, 2018‐E71001‐00), the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (2019M3E5D3073102, 2019R1H1A2039682, 2020R1F1A1074265), a Korea University grant (K1824431 and K1810951), an Ansan‐Si hidden champion fostering and supporting project funded by Ansan city, and computational resources provided by the University of Iowa, Iowa City, Iowa.
© 2022 John Wiley & Sons Ltd.
- brain atrophy
- cognitive decline
- insulin resistance
- type 2 diabetes
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism