1 H-Magnetic Resonance Spectroscopy Study of Auditory Cortex Metabolism in Patients with Type 2 Diabetes / 听力学及言语疾病杂志

ABSTRACT

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 groupsthe 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 .