摘要
目的 探讨静息状态下肥胖患者脑结构及功能改变的特点.方法 本研究为前瞻性.研究对象为2022年6月—2023年12月内分泌门诊随机获得的肥胖者,按纳入和排除标准纳入32名为肥胖组;同期招募25名年龄、性别及受教育年限相匹配的健康人为对照组(HC组).收集肥胖者的临床和影像资料及HC组的影像和匹配的健康资料.影像检查,颅脑容积采用矢状面磁化快速梯度回波序列,静息态fMRI采用多频段平面回波序列,获得指标包括灰质体积值、分数低频振幅值(fALFF)和功能连接值(FC),两组间这些数值的比较使用两独立样本t检验.将组间fALFF有差异的脑区设为ROI,计算两组FC值并行独立样本t检验,得到组间FC差异脑区.上述组间比较结果均使用错误发现率(FDR)校正,检验水准:P<0.05,体素水平阈值:P=0.001.使用RESTPLUS软件的Utilities功能分别提取组间差异有统计学意义脑区的灰质体积值、fALFF值和FC值,并分别与肥胖患者的BMI行Pearson相关性分析.结果(1)与HC组相比,肥胖患者右侧小脑8叶、左侧小脑6叶、左侧豆状核壳、右侧眶部额上回、左侧内侧额上回、右侧内侧和旁扣带脑回区域的灰质体积减小(P均<0.05),且肥胖患者BMI与左侧豆状核壳的体积值呈负相关(r=−0.52,P<0.005).(2)与HC组相比,肥胖患者左侧小脑8叶、双侧海马旁回、双侧丘脑、左侧豆状核壳、左侧中央前回、左侧顶下缘角回的fALFF值升高(P均<0.05);同时右侧小脑Crus2区、右侧背外侧额上回、左侧额中回的fALFF值降低(P均<0.05);且肥胖患者BMI与左侧小脑8叶、左侧海马旁回、左侧丘脑的fALFF值呈正相关(r值分别为0.57、0.45、0.49,P均<0.05),与右侧小脑Crus2区的fALFF值呈负相关(r=−0.5,P均<0.05).(3)肥胖组fALFF值异常升高脑区的峰值MNI坐标为种子点,分别绘制半径为3 mm的球形ROI,获得FC的显著变化脑区,与HC组相比,肥胖患者左侧小脑8叶-右侧颞中回、左侧小脑8叶-左侧颞下回、左侧小脑8叶-右侧枕下回、左侧小脑8叶-右侧豆状核壳、左侧小脑8叶-左侧豆状核壳、右侧海马旁回-右侧小脑9叶、左侧丘脑-右侧楔前叶、左侧顶下缘角回-右侧楔前叶FC强度增加(P均<0.05);且肥胖患者BMI与左侧小脑8叶-右侧枕下回、右侧海马旁回-右侧小脑9叶的FC强度呈正相关(r值分别为0.37、0.48,P均<0.05).结论 肥胖者大、小脑部分脑区灰质体积减小,部分脑区功能受损.这些变化主要发生在大脑奖赏、执行控制和情绪评估等系统相关脑区.脑结构及功能相关指标有望成为肥胖的神经影像标记,为肥胖及其并发症的发现与治疗提供新的思路.
Abstract
Objective To explore the characteristics of brain structural and functional changes in obese patients at rest. Methods This is a prospective study. The subjects were obese individuals randomly selected from the endocrinology outpatient clinic between June 2022 and December 2023. Thirty-two were included in the obesity group based on inclusion and exclusion criteria. During the same period,25 healthy individuals matched for age,gender,and years of education were recruited as the control group (HC group). Clinical and imaging data from the obese subjects and imaging and matched health data from the HC group were collected. Imaging examinations included cranial volume measured using sagittal magnetization-prepared rapid gradient-echo sequences and resting-state fMRI using multi-band echo-planar imaging sequences. The obtained metrics included gray matter volume,fractional amplitude of low-frequency fluctuations (fALFF),and functional connectivity (FC) values. Comparisons between the two groups were made using independent sample t-test. Brain regions with significant differences in fALFF between groups were set as regions of ROIs,and FC values were calculated and compared using independent sample t-test to identify regions with group differences in FC. All group comparisons were corrected using the false discovery rate (FDR),with a significance level of P<0.05 and a voxel-level threshold of P=0.001. The utility function of RESTPLUS software was used to extract the gray matter volume,Falff and FC values of the brain regions with statistically significant differences between groups,and Pearson correlation analysis was performed between the gray matter volume,Falff and FC values and BMI of obese patients. Results (1) Compared with the HC group,obese patients showed reduced gray matter volume in the right cerebellar lobule 8,left cerebellar lobule 6,left lentiform nucleus,right superior frontal gyrus,left medial superior frontal gyrus,and right medial and paracingulate gyri (all P<0.05),and BMI was negatively correlated with the volume of the left lentiform nucleus (r=−0.52;P<0.005). (2) Compared with the HC group,obese patients had increased fALFF values in the left cerebellar lobule 8,bilateral parahippocampal gyrus,bilateral thalamus,left lentiform nucleus,left precentral gyrus,and left inferior parietal lobule (all P<0.05);and decreased fALFF values in the right cerebellar Crus 2,right dorsolateral superior frontal gyrus,and left middle frontal gyrus (all P<0.05);BMI was positively correlated with fALFF values in the left cerebellar lobule 8,left parahippocampal gyrus,and left thalamus (r=0.57,0.45,0.49,respectively;all P<0.05),and negatively correlated with fALFF values in the right cerebellar Crus 2 (r=−0.5;P<0.05). (3) Using the peak MNI coordinates of the aforementioned brain regions with abnormal fALFF increases in the obese group as seed points,spherical ROIs with a radius of 3 mm were drawn to obtain significant changes in FC. Compared with the HC group,obese patients showed increased FC strength in the left cerebellar lobule 8-right middle temporal gyrus,left cerebellar lobule 8-left inferior temporal gyrus,left cerebellar lobule 8-right inferior occipital gyrus,left cerebellar lobule 8-right lentiform nucleus,left cerebellar lobule 8-left lentiform nucleus,right parahippocampal gyrus-right cerebellar lobule 9,left thalamus-right precuneus,and left inferior parietal lobule-right precuneus (all P<0.05);and BMI was positively correlated with FC strength in the left cerebellar lobule 8-right inferior occipital gyrus and right parahippocampal gyrus-right cerebellar lobule 9 (r=0.37,0.48,respectively;all P<0.05). Conclusions Obese individuals exhibit reduced gray matter volume impaired function in certain brain regions,particularly in areas related to the brain's reward,executive control,and emotional assessment systems. Indicators related to brain structure and function may serve as neuroimaging markers for obesity,offering new insights for the detection and treatment of obesity and its complications.
维普
万方数据