Association between visit-to-visit glucose variability and brain morphology and cognitive function in type 2 diabetes.

Objective: To investigate the effect of varying visit-to-visit glucose variability (GV) on brain morphometry and cognitive performance in patients with type 2 diabetes mellitus (T2DM).

Methods: This was a retrospective cohort study in which we recruited 426 participants (173 T2DM patients and 253 healthy controls) who underwent cognitive assessment and structural MRI. In patients with T2DM, visit-to-visit GV was calculated using the standard deviation of HbA1c during the follow-up period. Multiple linear regression models were used to analyze the associations between different levels of GV and brain morphometry as well as cognitive function after adjusting for mean HbA1c levels and other traditional risk factors.

Results: Higher GV is associated with poorer global cognitive performance and executive function. After full multivariate adjustment, higher GV is linked to cortical thinning in the left superior parietal cortex, right postcentral gyrus, and insula, as well as a reduction in total gray matter volume. In contrast, no association was observed between GV and cortical volume or surface area.

Conclusions: Our findings indicate that higher visit-to-visit GV is associated with reduced cortical thickness, total gray matter volume atrophy, and poorer cognitive performance in patients with T2DM, and these associations are independent of mean HbA1c levels.