Approximately 6.6% of the global population carries a diagnosis of type 2 diabetes mellitus (T2DM). Patients with T2DM are at greater risk for developing dementia and Alzheimer’s disease (AD) and have been reported to exhibit inferior cognitive performance when compared to age-matched healthy controls.
In a recently published study, researchers characterized the neurocognitive effects associated with T2DM in a cohort of subjects from the UK Biobank. The results appear in the journal eLife.
Marked Acceleration of Brain Aging
For the study, the researchers used information from the UK Biobank and included data from 20,314 participants, 1,012 who had T2DM and 19,302 healthy controls, aged between 50 to 80 years. They were followed up for up to 31 years, with a mean of 8.5 ± 6.1 years.
The team found that when compared to the healthy controls, patients with T2DM showed deficits in cognitive performance, even after controlling for age, sex, education, and hypertension.
The cognitive deficits were accompanied by marked brain atrophy, which was more severe in the ventral striatum, a region critical to learning, decision-making, goal-directed behavior, and cognitive control. The cerebellum also showed atrophy, and it is believed to be because these 2 brain regions contain the densest concentrations of insulin-dependent GLUT-4 compared to non-insulin-dependent isoforms GLUT-1 and GLUT-3, which are glucose transporters.
According to the results, the neurocognitive effect of T2DM suggests marked acceleration of normal brain aging, with gray matter atrophy occurring approximately 26% ± 14% faster than seen with normal aging. Disease duration was associated with increased neurodegeneration.
Botond Antal, et al. Type 2 diabetes mellitus accelerates brain aging and cognitive decline: Complementary findings from UK Biobank and meta-analyses. 2022. eLife. DOI: https://doi.org/10.7554/eLife.73138