Geijselaers Stefan L C, Sep Simone J S, Schram Miranda T, van Boxtel Martin P J, Henry Ronald M A, Verhey Frans R J, Kroon Abraham A, Schaper Nicolaas C, Dagnelie Pieter C, van der Kallen Carla J H, Stehouwer Coen D A, Biessels Geert Jan
Department of Internal Medicine, Maastricht University Medical Center +, Maastricht, the Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
Department of Internal Medicine, Maastricht University Medical Center +, Maastricht, the Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands.
J Diabetes Complications. 2017 May;31(5):824-830. doi: 10.1016/j.jdiacomp.2017.01.020. Epub 2017 Feb 12.
Type 2 diabetes, hyperinsulinemia, and insulin resistance are associated with cognitive impairment. Experimental studies indicate that insulin signaling in the brain is related to cognitive performance. Here we evaluated whether insulin-related variables contribute to the variance in cognitive performance among individuals with type 2 diabetes.
A total of 806 individuals with type 2 diabetes (mean age 62±8years, HbA1c 6.9±1.1%) completed a neuropsychological test battery. Insulin-related variables evaluated were: fasting plasma insulin, C-peptide, and the Homeostasis Model Assessment (HOMA2-IR; in individuals without insulin treatment; n=641). The unadjusted coefficient of determination (R), obtained from multiple linear regression analyses, was used to estimate the proportion of variance in cognition explained by insulin-related variables.
Sex, age, and educational level together explained 18.0% (R) of the variance in memory function, 26.5% in information processing speed, and 22.8% in executive function and attention. Fasting insulin, C-peptide, or HOMA2-IR did not increase the explained variance (maximum ΔR 0.3%, P≥0.14). Similar results were obtained when insulin-related variables were added to models that additionally included glycemic control, cardiovascular risk factors, and depression.
Our results show that measures of peripheral insulin resistance are unrelated to cognitive performance among individuals with adequately controlled type 2 diabetes.
2型糖尿病、高胰岛素血症和胰岛素抵抗与认知障碍有关。实验研究表明，大脑中的胰岛素信号与认知表现有关。在此，我们评估了胰岛素相关变量是否会导致2型糖尿病患者认知表现的差异。
共有806名2型糖尿病患者（平均年龄62±8岁，糖化血红蛋白6.9±1.1%）完成了一套神经心理学测试。评估的胰岛素相关变量包括：空腹血浆胰岛素、C肽和稳态模型评估（HOMA2-IR；未接受胰岛素治疗的个体；n=641）。通过多元线性回归分析获得的未调整决定系数（R）用于估计胰岛素相关变量所解释的认知差异比例。
性别、年龄和教育水平共同解释了记忆功能差异的18.0%（R）、信息处理速度差异的26.5%以及执行功能和注意力差异的22.8%。空腹胰岛素、C肽或HOMA2-IR并未增加所解释的差异（最大ΔR 0.3%，P≥0.14）。当将胰岛素相关变量添加到另外包括血糖控制、心血管危险因素和抑郁的模型中时，也得到了类似的结果。
我们的结果表明，在2型糖尿病控制良好的个体中，外周胰岛素抵抗指标与认知表现无关。
