Background and objectives: Peroral supplementation with trivalent-chromium (Cr) or magnesium (Mg) has been shown to improve insulin resistance (IR). The objective of this study was to determine whether combined peroral supplementation with Cr and Mg improves IR more effectively than Cr or Mg alone.
Methods and study design: Subjects (n=120, age range 45-59 years old) and diagnosed with IR were randomly divided into four groups and monitored for a period of 3 months: group 1 (the placebo control group), group 2 (160 μg/d Cr), group 3 (200 mg/d Mg), and group 4 (160 μg/d Cr plus 200 mg/d Mg). Fasting blood glucose (FBG), fasting insulin (FIns), erythrocyte Cr and Mg content, and glucose-transporter-4 (GLUT4) and glycogen-synthase-kinase-3β (GSK3β) mRNA levels in activated T-lymphocytes were measured, and insulin resistant index (IRI) was calculated.
Results: Significant decreases between the baseline and study conclusion values of FBG (0.37 mmol/L, p<0.01), FIns (2.91 μIU/mL, p<0.01) and IRI (0.60, p<0.01) were observed in group 4, but not groups 1-3. Similarly, compared with baseline, significant changes in GLUT4 (2.9-fold increase, p<0.05) and GSK3β (2.2-fold decrease, p<0.05) mRNA levels in activated T-lymphocyte were observed at the study's conclusion in group 4, but not in groups 1-3.
Conclusions: Our results indicate that combining peroral supplementation with Cr and Mg improves IR more effectively than Cr or Mg alone, and this may be attributable to increased induction and repression, respectively, of GLUT4 and GSK3β expression.
背景与目的:现有研究表明口服三价铬或镁可有效改善胰岛素抵抗。本研究旨在 确定铬和镁联合补充是否较单独补充铬或镁更能有效地改善胰岛素抵抗。方法与 研究设计:本研究纳入了120 名诊断为胰岛素抵抗的病人(45-59 岁),随机将 其分为4 组,每组30 人,分别口服安慰剂、铬(160 μg/d)、镁(200 mg/d)、 镁+铬(铬160 μg/d+镁200 mg/d),持续3 个月。测定空腹血糖和胰岛素浓度、 红细胞中铬和镁的含量,以及激活的T 淋巴细胞中葡萄糖转运载体4(GLUT4) 和糖原合成酶激酶3β(GSK3β)的mRNA 水平,并计算胰岛素抵抗指数。结 果:与干预前相比,铬和镁联合补充可以显著降低空腹血糖 (0.37 mmol/L, p<0.01 ) 和胰岛素 ( 2.91 μIU/mL , p<0.01 ) 浓度, 以及胰岛素抵抗指数 (0.60,p<0.01);同时铬和镁联合补充显著上调了活化的T 细胞GLUT4 mRNA 水平(升高2.9 倍,p<0.05),并显著下调了 GSK3β mRNA 水平 (降低 2.2 倍,p<0.05)。对照组、铬或镁单独补充组与干预前相比改善效果不明显。 结论:铬和镁联合补充较单独补充铬或镁能更好地改善胰岛素抵抗,可能与铬和 镁联合补充使胰岛素信号传导通路中GLUT-4mRNA 上调和GSK3β mRNA 下调 有关。.