不伴认知障碍的中年2型糖尿病患者脑白质微结构改变

Changes of white matter microstructure in middle-aged patients with type 2 diabetes mellitus and no cognitive impairment

目的探讨不伴认知障碍的中年2型糖尿病(T2DM)患者脑白质微结构改变与认知功能的潜在联系。方法收集26例不伴认知障碍的中年T2DM患者及25例年龄、性别、受教育程度相匹配的健康被试(HC)临床及影像资料,采用TBSS方法对全脑白质微观结构完整性进行评价,提取存在显著差异脑区的参数值与神经心理学量表及临床变量进行相关性分析。结果相对于HC,不伴认知障碍的中年T2DM患者脑白质微观结构存在广泛损伤,尤其是胼胝体、双侧放射冠、内外囊、右侧丘脑后辐射(含视辐射)等脑白质区域FA降低、MD和RD升高。此外,T2DM组右侧丘脑后辐射(含视辐射)FA值与画钟实验(CDT)评分呈正相关(P=0.022,r=0.448),即使将年龄及受教育程度作为协变量,以上正相关依然存在(P=0.034,r=0.434)。结论不伴认知障碍的中年T2DM患者存在广泛的脑白质微观结构改变,可能与脑白质脱髓鞘有一定的联系;即使在整体认知功能没有异常的情况下,其视觉空间功能已经受损;右侧丘脑后辐射(含视辐射)可能是早期识别T2DM认知改变的敏感影像学标记物。

Objective To explore the potential relationship between the changes of white matter microstructure and cognitive function in middle-aged patients with type 2 diabetes mellitus(T2DM)and no cognitive impairment.Methods 26 middle-aged T2DM patients without cognitive impairment and 25 healthy volunteers matched in age,gender and education level were enrolled in this study.TBSS was used to evaluate the integrity of the whole brain white matter microstructure.The parameters of the brain regions with significant differences were correlated with the neuropsychological scale and clinical variables.Results Compared with healthy control,the middle-aged T2DM patients without cognitive impairment had extensive damage to the white matter microstructure with decreased FA and increased MD and RD,especially in the corpus callosum,bilateral corona radiata,internal and external capsules,and right posterior thalamus radiation including visual radiation.The FA of the right posterior thalamus radiation in the T2DM group was positively correlated with the clock drawing test(CDT)score(P=0.022,r=0.448).The positive correlation persisted even when age and education level were used as covariates(P=0.034,r=0.434).Conclusion Middle-aged T2DM patients without cognitive impairment have extensive changes in the white matter microstructure,which may be related to the demyelination of the white matter.The overall cognitive function is normal whereas the visual spatial function is impaired.The right posterior thalamus radiation including visual radiation may be a sensitive imaging marker for early detection of cognitive changes.