不同体重者下丘脑对葡萄糖耐量试验的反应  

The central sensitivity of hypothalamus to oral glucose loading in subjects with different body weight

作　　者：张铁梅[1] 陈敏[1] 罗森林[2] 张颖[2] 周天罡 张延[1] 宫环[1] 吴小萌[1] 韩彩和[1] 戴雪松[1] 阎颖[1] 

机构地区：[1]卫生部北京医院,北京100730 [2]北京理工大学 [3]北京磁共振脑成像中心

出　　处：《中华糖尿病杂志（1006-6187）》2005年第5期353-356,共4页

基　　金：国家重点基础研究资助项目(G2000057008);国家自然科学基金资助项目(30370432)

摘　　要：目的应用功能核磁共振观察不同体重者下丘脑对口服葡萄糖耐量试验的反应,揭示不同体重者下丘脑中枢糖代谢调节的敏感性与代谢紊乱发生的关系。方法分别采集10名正常体重者与10名肥胖者口服75克葡萄糖后的下丘脑功能磁共振图像数据以及腹部解剖结构图像数据;同时测定受试者的空腹血糖、游离脂肪酸及相应激素水平。应用自行建立的灰度平均值方法进行图像分析处理;同时进行受试者脑功能信号参数与血生化指标水平、相应激素水平及腹部脂肪含量的相关分析。结果不同体重者口服葡萄糖后在下丘脑部位均出现一过性的抑制反应。但肥胖者此抑制反应出现的时间较正常体重者明显延迟;抑制反应强度明显低于正常体重者;抑制反应恢复时间也明显迟于正常体重者。受试者的空腹血浆胰岛素及其痩素水平与其下丘脑抑制信号恢复到基线的时间有关联;受试者的腹部脂肪含量与其下丘脑抑制信号恢复到基线的时间亦有关联。而受试者空腹血浆葡萄糖、游离脂肪酸水平与其下丘脑功能磁共振采集信号各项参数间没有关联。结论不同体重者下丘脑对糖负荷的中枢反应有所不同,肥胖者下丘脑对糖刺激反应的敏感性有所降低。功能核磁共振是确定脑特定区域功能的一个有效手段。Objective To investigate central response of hypothalamus to 75 g oral glucose loading by functional magnetic resonance imaging（fMRI）. Methods The signal of hypothalamus was monitored by fMRI for 50 minutes in 20 persons with two types of body weight （10 obese subjects and 10 normal body weight subjects） after 75 g oral glucose intake. The plasmas for leptin, insulin, free fatty acid and glucose determinations were also collected during the procedure. Results Both lean and obese subjects demonstrated an inhibition of the fMRI signal after glucose intake, but in obese subjects, the inhibition was attenuated and delayed compared with lean subjects （1.94±1.06 min vs 1.0 ±0. 71 min,P〈0.05）. The time taken to recover to the base line after inhibition was also delayed compared with lean subjects （26.62 ± 7. 35 min vs 16.29 ± 6.42 min, P〈0.01） and correlated with the fasting plasma leptin, insulin concentrations and abdominal fat areas in both lean and obese subjects（r=0. 718-0. 509, P〈0. 05）. Conclusion Hypothalamus response to glucose loading in lean and obese humans was different. The glucose-induced central sensitivity of hypothalamus was attenuated in obese subjects.

关 键 词：下丘脑 磁共振成像 功能性 葡萄糖耐量试验 

分 类 号：R587.1[医药卫生—内分泌] R614.42[医药卫生—内科学]