Inefficient activity in working memory related brain regions in patients with type 2 diabetes mellitus
ZHANG Hui-mei1, LI Wei1, ZHANG Yang1, LU Shan2, LI Nan1, NI Chang-lin2, ZHANG Quan1
1.Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, China; 2.Tianjin Medical University Metabolic Diseases Hospital, Tianjin 300060
Abstract：Objective: To investigate the altered activity of working memory related brain regions in patients with type 2 diabetes mellitus(T2DM), and the possible neural mechanisms. Methods: Twenty-one T2DM patients and 21 normal subjects received functional MRI(fMRI) scanning with a 1-back working memory(WM) task in this study. The fMRI data were preprocessed using SPM8. One-sample t-test and two-sample t-test were used to analyze the WM related brain activity within and between groups, respectively. Statistical thresholds were set at P<0.01(AlphaSim correction). BOLD percent signal change(PSC) of regions with intergroup difference was calculated and the correlation analyses were performed between the PSC and the response time(RT) of 1-back task and glycosylated hemoglobin level. Results: The fasting plasma glucose and glycosylated hemoglobin level were significantly higher in T2DM patients than controls(P<0.001), and accuracy of 1-back task was significantly lower than that of controls(P<0.05). Compared to the controls, T2DM patients showed significantly higher activation in the bilateral dorsolateral and ventrolateral prefrontal cortex and the right posterior parietal cortex(P<0.01), and significantly lower deactivation in the left inferior parietal lobule and the right superior frontal gyrus(P<0.01). Significant negative correlations were found between the PSC of the bilateral dorsolateral prefrontal cortex and the RT in T2DM group(P<0.05). Conclusion: Hyperactivation of the WM related brain regions may have a limited compensation for the decreased WM behavior in T2DM patients.
2015, Vol. 26 
