Sahin Ibrahim, Alkan Alpay, Keskin Lezzan, Cikim Ayse, Karakas Hakki M, Firat Ahmet K, Sigirci Ahmet
Department of Endocrinology and Metabolism, School of Medicine, Inonu University, TR-44069 Malatya, Turkey.
J Diabetes Complications. 2008 Jul-Aug;22(4):254-60. doi: 10.1016/j.jdiacomp.2007.03.007. Epub 2008 Apr 16.
The aim of this study was to investigate possible metabolic alterations in cerebral tissues on magnetic resonance spectroscopy (MRS) in patients with impaired glucose tolerance (IGT) and with type 2 diabetes mellitus (T2-DM). Twenty-five patients with T2-DM, 13 patients with IGT, and 14 healthy volunteers were included. Single-voxel spectroscopy (TR: 2000 ms, TE: 31 ms) was performed in all subjects. Voxels were placed in the frontal cortex, thalamus, and parietal white matter. N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and myo-inositol (MI)/Cr ratios were calculated. Frontal cortical Cho/Cr ratios were increased in patients with IGT compared to control subjects. Parietal white matter Cho/Cr ratios were significantly higher in patients with IGT when compared to patients with T2-DM. In the diabetic group, frontal cortical MI/Cr ratios were increased, and parietal white matter Cho/Cr ratios were decreased when compared to the control group. Frontal cortical NAA/Cr and Cho/Cr ratios and parietal white matter Cho/Cr ratios were decreased in diabetic patients with poor glycemic control (A1C>10%). A1C levels were inversely correlated with frontal cortical NAA/Cr and Cho/Cr ratios and with parietal white matter Cho/Cr ratios. T2-DM and IGT may cause subtle cerebral metabolic changes, and these changes may be shown with MRS. Increased Cho/Cr ratios may suggest dynamic change in membrane turnover in patients with IGT. Diabetic patients with poor glycemic control may be associated with neuronal dysfunction/damage in brain in accordance with A1C levels and, in some, extend with insulin resistance.
本研究旨在通过磁共振波谱分析（MRS）调查糖耐量受损（IGT）患者和2型糖尿病（T2-DM）患者脑组织中可能存在的代谢改变。纳入了25例T2-DM患者、13例IGT患者和14名健康志愿者。对所有受试者进行了单体素波谱分析（重复时间：2000毫秒，回波时间：31毫秒）。体素置于额叶皮质、丘脑和顶叶白质。计算了N-乙酰天门冬氨酸（NAA）/肌酸（Cr）、胆碱（Cho）/Cr和肌醇（MI）/Cr的比值。与对照组相比，IGT患者额叶皮质Cho/Cr比值升高。与T2-DM患者相比，IGT患者顶叶白质Cho/Cr比值显著更高。在糖尿病组中，与对照组相比，额叶皮质MI/Cr比值升高，顶叶白质Cho/Cr比值降低。血糖控制不佳（糖化血红蛋白>10%）的糖尿病患者额叶皮质NAA/Cr和Cho/Cr比值以及顶叶白质Cho/Cr比值降低。糖化血红蛋白水平与额叶皮质NAA/Cr和Cho/Cr比值以及顶叶白质Cho/Cr比值呈负相关。T2-DM和IGT可能会引起细微的脑代谢变化，而这些变化可能通过MRS显示出来。Cho/Cr比值升高可能提示IGT患者膜周转率的动态变化。血糖控制不佳的糖尿病患者可能根据糖化血红蛋白水平与脑内神经元功能障碍/损伤相关，在某些情况下还与胰岛素抵抗有关。
