Functional brain networks are altered in type 2 diabetes and pre-diabetes signs for compensation of cognitive decrements? - The Maastricht Study: signs for compensation of cognitive decrements? - The Maastricht Study

Type 2 diabetes is associated with cognitive decrements, accelerated cognitive decline, and increased risk for dementia. Participants with the metabolic syndrome, a major risk factor for diabetes, may display comparable cognitive decrements as seen in type 2 diabetes. Currently, the impact of (pre-)diabetes on cognition and the underlying organization of functional brain networks still remain to be elucidated. This study was designed to investigate whether functional brain networks are affected in type 2 diabetes and pre-diabetes. Forty-seven participants with diabetes, 47 pre-diabetic participants, and 45 control participants underwent detailed cognitive testing and 3-Tesla resting state functional MRI. Graph theoretical network analysis was performed to investigate alterations in functional cerebral networks. Participants with diabetes displayed altered network measures, characterized by a higher normalized cluster coefficient and higher local efficiency compared with controls. The network measures of the pre-diabetic participants fell between those of the diabetes and control participants. Lower processing speed was associated with shorter path length and higher global efficiency. To conclude, participants with type 2 diabetes have altered functional brain networks. This alteration is already apparent in the pre-diabetic stage to a somewhat lower level, hinting at functional reorganization of the cerebral networks as compensatory mechanism for cognitive decrements.