Prefrontal cortex brain damage and glycemic control in patients with type 2 diabetes

BACKGROUND: This study examined brain tissue integrity in sites that controls cognition (prefrontal cortices; PFC) and its relationships to glycemic outcomes in adults with type 2 diabetes mellitus (T2DM). METHODS: We examined 28 T2DM patients (median age 57.1 years; median body mass index [BMI] 30.6 kg/m(2) ;11 males) and 47 healthy controls (median age 55.0 years; median BMI 25.8 kg/m(2) ; 29 males) for cognition (Montreal Cognitive Assessment [MoCA]), glycemic control (hemoglobin A1c [HbA1c]), and PFC tissue status via brain magnetic resonance imaging (MRI). High-resolution T1-weighted images were collected using a 3.0-Tesla MRI scanner, and PFC tissue changes (tissue density) were examined with voxel-based morphometry procedures. RESULTS: Reduced PFC density values were observed in T2DM patients compared to controls (left, 0.41 +/- 0.02 mm(3) /voxel vs 0.44 +/- 0.02 mm(3) /voxel, P < 0.001; right, 0.41 +/- 0.03 mm(3) /voxel vs 0.45 +/- 0.02 mm(3) /voxel, P < 0.001). PFC density values were positively correlated with cognition; left PFC region (r = 0.53, P = 0.005) and right PFC region (r = 0.56, P = 0.003), with age and sex as covariates. Significant negative correlations were found between PFC densities and HbA1c values; left PFC region (r = -0.39, P = 0.049) and right PFC region (r = -0.48, P = 0.01), with age and sex as covariates. CONCLUSIONS: T2DM patients showed PFC brain tissue damage, which is associated with cognitive deficits and poor glycemic control. Further research is needed to identify causal relationships between HbA1c, cognition, and brain changes in T2DM and to evaluate the impact of interventions to prevent brain tissue injury or neuroregeneration in this high-risk patient population, to eventually preserve or enhance cognition and improve glucose outcomes. HIGHLIGHTS: T2DM patients have prefrontal cortices changes over non-T2DM healthy individuals. Prefrontal cortices tissue changes are associated with cognitive deficits in T2DM patients. Prefrontal cortices damage is associated with poor glycemic control in T2DM.