Selectively disrupted functional connectivity networks in type 2 diabetes mellitus

Background: The high prevalence of type 2 diabetes mellitus (T₂DM) in individuals over 65 years old and cognitive deficits caused by T₂DM have attracted broad attention. The pathophysiological mechanism of T₂DM-induced cognitive impairments, however, remains poorly understood. Previous studies have suggested that the cognitive impairments can be attributed not only to local functional and structural abnormalities but also to specific brain networks. Thus, our aim is to investigate the changes of global networks selectively affected by T₂DM. Methods: A resting state functional network analysis was conducted to investigate the intrinsic functional connectivity in 37 patients with diabetes and 40 healthy controls who were recruited from local communities in Beijing, China. Results: We found that patients with T₂DM exhibited cognitive function declines and functional connectivity disruptions within the default mode network, left frontal parietal network, and sensorimotor network. More importantly, the fasting glucose level was correlated with abnormal functional connectivity. Conclusion: These findings could help to understand the neural mechanisms of cognitive impairments in T₂DM and provide potential neuroimaging biomarkers that may be used for early diagnosis and intervention in cognitive decline.