Department of Psychology, The University of Texas at Austin, Austin, TX, USA; University of Texas Imaging Research Center, Austin, TX, USA.
Obesity (Silver Spring). 2013 Oct;21(10):2007-13. doi: 10.1002/oby.20332. Epub 2013 May 25.
To examine the role of hypertension, hyperglycemia, and dyslipidemia in potentially accounting for obesity-related brain vulnerability in the form of altered cerebral neurochemistry.
Sixty-four adults, ages 40-60 years, underwent a health screen and proton magnetic resonance spectroscopy ((1) H MRS) of occipitoparietal gray matter to measure N-acetyl aspartate (NAA), choline (Cho), myo-inositol (mI), and glutamate (Glu) relative to creatine (Cr). The causal steps approach and nonparametric bootstrapping were utilized to assess if fasting glucose, mean arterial pressure or peripheral lipid/lipoprotein levels mediate the relationship between body mass index (BMI) and cerebral neurochemistry.
Higher BMI was significantly related to higher mI/Cr, independent of age and sex. BMI was also significantly related to two of the proposed mediators, triglyceride, and HDL-cholesterol, which were also independently related to increased mI/Cr. Finally, the relationship between BMI and mI/Cr was significantly attenuated after inclusion of triglyceride and HDL-cholesterol into the model, one at a time, indicating statistical mediation.
Higher triglyceride and lower HDL levels statistically account for the association between BMI and myo-inositol, pointing toward a potentially critical role for dyslipidemia in the development of cerebral neurochemical alterations in obesity.
研究高血压、高血糖和血脂异常在解释肥胖相关的大脑易损性方面的作用，这种易损性表现为大脑神经化学的改变。
64 名 40-60 岁的成年人接受了健康筛查和枕顶叶灰质的质子磁共振波谱((1)H MRS)，以测量 N-乙酰天冬氨酸 (NAA)、胆碱 (Cho)、肌醇 (mI)和谷氨酸 (Glu)与肌酸 (Cr)的相对比值。采用因果步骤法和非参数自举法来评估空腹血糖、平均动脉压或外周血脂/脂蛋白水平是否介导了体重指数 (BMI)与大脑神经化学之间的关系。
较高的 BMI 与较高的 mI/Cr 显著相关，与年龄和性别无关。BMI 也与两个被提议的中介物，甘油三酯和高密度脂蛋白胆固醇显著相关，这两个中介物也与 mI/Cr 的增加独立相关。最后，在逐个纳入甘油三酯和高密度脂蛋白胆固醇进入模型后，BMI 和 mI/Cr 之间的关系显著减弱，表明存在统计学上的中介作用。
较高的甘油三酯和较低的高密度脂蛋白水平在统计学上解释了 BMI 与肌醇之间的关联，提示血脂异常在肥胖相关的大脑神经化学改变的发展中可能起着关键作用。
