2型糖尿病患者听皮层区磁共振氢质子波谱分析

1 H-Magnetic Resonance Spectroscopy Study of Auditory Cortex Metabolism in Patients with Type 2 Diabetes

目的探讨磁共振氢质子波谱(1 H magnetic resonance spectroscopy,1 H-MRS)技术对2型糖尿病患者听皮层神经细胞损伤的早期预警作用。方法随机抽取确诊的糖尿病患者98例,根据纯音听阈将其分为糖尿病并双侧耳聋组(32例)、糖尿病并单侧耳聋组(18例)、单纯糖尿病组(48例),以健康志愿者15例为正常对照组,各组行双侧颞横回听皮层1 H-MRS检测,根据神经代谢产物其峰下面积计算N-乙酰天门冬氨酸/肌酸(NAA/Cr)、胆碱/肌酸(Cho/Cr)、肌醇/肌酸(mI/Cr)、N-乙酰天门冬氨酸/胆碱(NAA/Cho)值,比较各组间上述各项指标的差异;对血糖值与各神经代谢产物的相关性进行Pearson相关分析,根据ROC曲线面积判定上述各指标诊断早期糖尿病并感音神经性听力损失的灵敏度及特异度。结果糖尿病患者空腹血糖值与NAA/Cr、NAA/Cho呈负相关(P<0.05),与Cho/Cr、mI/Cr呈正相关(P<0.05);与正常对照组相比,单纯糖尿病组听皮层神经代谢产物NAA/Cho、NAA/Cr降低(P<0.05),Cho/Cr、mI/Cr升高;糖尿病合并双侧耳聋组NAA/Cho降低(P<0.05),Cho/Cr升高;糖尿病合并单侧耳聋组患侧和健侧NAA/Cho均下降,且患侧NAA/Cho较健侧降低(P<0.05)。NAA/Cho的ROC曲线下面积为81%,准确性较高,且当NAA/Cho为1.65时可以作为单纯糖尿病与糖尿病合并感音神经性聋的分界指标,其余神经代谢产物ROC曲线下面积均<50%。结论听皮层磁共振氢质子波谱分析指标NAA/Cho有可能作为判定糖尿病人群发生感音神经性聋的早期听皮层代谢预警指标。

Objective To investigate the characteristic changes of the metabolism products in the auditory cortex （transverse temporal gyrus） in diabetes combined with nerve deafness using 1 H magnetic resonance spectros‐copy （1 H -MRS） ,and to discover the early warning indicator of nerve deafness in type 2 diabetes .Methods PTA was performed in 98 patients with type 2 diabetes （diagnosed by Endocrinology Department） ,and in 15 healthy sub‐jects in the control group .The patients were classified into four groups ：the group of type 2 diabetes;type 2 diabe‐tes with unilateral and bilateral deafness ,and the normal control group .Cerebral metabolism was studied by assess‐ing the ratios of nitro -acetyl aspartate contrast to choline （NAA/Cho） as well as to creatine （NAA/Cr） ,myo-in‐ositol to creatine （mI/Cr） and choline to creatine （Cho/Cr） ratios in the auditory cortical separately in these groups . The Pearson correlation analysis was applied to determine blood glucose value with the nerve metabolites while the ROC curves were made for those metabolism markers to find the best diagnostic threshold .Results NAA/Cr and NAA/Cho were negatively correlated with AHI index and Cho/Cr ,mI/Cr was positively correlated with blood glu‐cose value .Significantly lower values of NAA/Cho ratio were found in patients＇（diabetes without deafness） auditory cortex compared with 15 age-matched control subjects （P〈0 .05） .NAA/Cr and NAA/Cho ratio in diabetes with deafness were significantly lower than those in control group （P〈 0 .05） ,Cho/Cr higher than those of in other groups （P〈0 .05） .NAA/Cr and NAA/Cho ratio in injured and uninjured auditory cortex of diabetes with unilateral deafness were significantly lower than those of in control group （P〈0 .05） ,then we made a self -comparison be‐tween the injured and uninjured auditory cortex ,finding that NAA/Cho ratio had a significant difference .All of the metabolisms were tested by the curve of ROC .The area of NAA/Cho under the ROC curve was 81% ,which had a higher accuracy .NAA/Cho equal to 1 .65 can be used as boundary indicators between diabetes without deafness and diabetes with deafness groups ,the areas of the remaining indicators under the ROC curve was〈50% .Conclusion NAA/Cho may be the early warning marker of nerve deafness in type 2 diabetes .