Schur Ellen A, Melhorn Susan J, Oh Seok-Kyun, Lacy J Matthew, Berkseth Kathryn E, Guyenet Stephan J, Sonnen Joshua A, Tyagi Vidhi, Rosalynn Mary, De Leon B, Webb Mary F, Gonsalves Zenobia T, Fligner Corinne L, Schwartz Michael W, Maravilla Kenneth R
Department of Medicine, University of Washington, Seattle, Washington, USA.
Division of General Internal Medicine, University of Washington, Seattle, Washington, USA.
Obesity (Silver Spring). 2015 Nov;23(11):2142-8. doi: 10.1002/oby.21248.
To use quantitative magnetic resonance imaging (MRI) to test whether mediobasal hypothalamic (MBH) gliosis is associated with obesity and insulin resistance in humans.
Sixty-seven participants underwent a fasting blood draw and MRI. Cases with radiologic evidence of MBH gliosis (N = 22) were identified as the upper tertile of left MBH T2 relaxation time and were compared to controls (N = 23) from the lowest tertile. In a separate postmortem study, brain slices (N = 10) through the MBH were imaged by MRI and stained for glial fibrillary acidic protein (GFAP).
In all participants, longer T2 relaxation time in the left MBH was associated with higher BMI (P = 0.01). Compared with controls, cases had longer T2 relaxation times in the right MBH (P < 0.05), as well as higher BMI (P < 0.05), fasting insulin concentrations (P < 0.01), and HOMA-IR values (P < 0.01), adjusted for sex and age. Elevations in insulin and HOMA-IR were also independent of BMI. In the postmortem study, GFAP staining intensity was positively associated with MBH T2 relaxation time (P < 0.05), validating an MRI-based method for the detection of MBH gliosis in humans.
These findings link hypothalamic gliosis to insulin resistance in humans and suggest that the link is independent of the level of adiposity.
运用定量磁共振成像（MRI）检测人类下丘脑内侧基底部（MBH）胶质增生是否与肥胖及胰岛素抵抗相关。
67名参与者接受了空腹采血及MRI检查。根据MBH胶质增生的影像学证据，将左MBH T2弛豫时间处于上三分位数的病例（N = 22）确定为病例组，并与下三分位数的对照组（N = 23）进行比较。在另一项尸检研究中，对穿过MBH的脑切片（N = 10）进行MRI成像，并对胶质纤维酸性蛋白（GFAP）进行染色。
在所有参与者中，左MBH的T2弛豫时间延长与较高的体重指数（BMI）相关（P = 0.01）。与对照组相比，病例组右MBH的T2弛豫时间更长（P < 0.05），BMI更高（P < 0.05），空腹胰岛素浓度更高（P < 0.01），稳态模型评估的胰岛素抵抗（HOMA - IR）值更高（P < 0.01），并对性别和年龄进行了校正。胰岛素和HOMA - IR的升高也与BMI无关。在尸检研究中，GFAP染色强度与MBH T2弛豫时间呈正相关（P < 0.05），验证了一种基于MRI检测人类MBH胶质增生的方法。
这些发现将下丘脑胶质增生与人类胰岛素抵抗联系起来，并表明这种联系独立于肥胖程度。
