2型糖尿病患者脑部皮层及皮层下奖赏环路研究

Volume changes of cortical and subcortical reward circuitry in the brain of patients with type 2 diabetes mellitus

目的探索2型糖尿病患者皮层及皮层下奖赏环路体积变化,以及胰岛素治疗对奖赏环路的影响。方法对16名2型糖尿病患者及16名健康志愿者进行脑形态学分析,其中11名2型糖尿病患者进行基线(胰岛素治疗前)及随访水平(胰岛素治疗1年)的体积测量。统计学方法采用协方差分析及配对t检验。结果 2型糖尿病患者左侧岛叶及伏隔核区、右侧海马、壳核及杏仁核体积显著小于对照组。接受胰岛素治疗1年后双侧皮层奖赏系统体积(左侧:33.65±3.66 ml;右侧:33.35±4.25 ml)显著高于基线水平(左侧:31.45±2.90 ml;右侧:31.12±2.97 ml);双侧基底节食物奖赏系统结构体积无显著差异;双侧腹侧间脑体积随访水平(左侧:3.26±0.68 ml;右侧:3.20±0.78 ml)较基线水平(左侧:2.96±0.76 ml;右侧:2.82±0.90 ml)显著增加(P<0.05)。结论 2型糖尿病患者皮层及皮层下奖赏系统结构体积减小,胰岛素治疗可以改善皮层及皮层下奖赏系统结构的损害。

Objective To elucidate the volume changes of cortical and subcortical reward circuitry in patients with type 2 diabetes mellitus. Methods High-resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI images were obtained from 16 patients with type 2 diabetes mellitus and 16 normal controls, and 11 type 2 diabetic patients also received the same MRI scans after insulin therapy for 1 year. Volumetric analysis was performed and analysis of covariance and paired t test were applied. Results A decreased volume was found in the left insular lobe, left nucleus accumbens area, right hippocampus, putamen and amygdala in type 2 diabetic patients compared with normal controls （P〈0.05）. After insulin therapy for 1 year, an increased volume of bilateral cortical reward structures was observed （left, 33.65 ± 3.66 ml;right, 33.35 ± 4.25 ml） compared the baseline level （left, 31.45 ± 2.90 ml; right, 31.12 ± 2.97 ml） in diabetic patients （P〈0.05）. No significant volume change in the bilateral basal ganglia structures was found after insulin therapy for 1 year （P〉0.05）, and bilateral ventral diencephalon area showed an increased volume after the treatment （left, 3.26±0.68 ml;right, 3.20±0.78 ml） compared with the baseline （left, 2.96 ± 0.76 ml;right, 2.82 ± 0.90 ml） （P〈0.05）. Conclusion Type 2 diabetic patients have a decreased volume of the cortical and subcortical reward circuitry, and insulin therapy can reverse such changes and improve the damage of reward circuitry.