PDF(Pubmed)
Abstract：
Type 2 diabetes mellitus, a condition preceded by prediabetes, is documented to compromise skeletal muscle health, consequently affecting skeletal muscle structure, strength, and glucose homeostasis. A disturbance in skeletal muscle functional capacity has been demonstrated to induce insulin resistance and hyperglycemia. However, the modifications in skeletal muscle function in the prediabetic state are not well elucidated. Hence, this study investigated the effects of diet-induced prediabetes on skeletal muscle strength in a prediabetic model. Male Sprague Dawley rats were randomly assigned to one of the two groups (n = 6 per group; six prediabetic (PD) and six non-pre-diabetic (NPD)). The PD group (n = 6) was induced with prediabetes for 20 weeks. The diet that was used to induce prediabetes consisted of fats (30% Kcal/g), proteins (15% Kcal/g), and carbohydrates (55% Kcal/g). In addition to the diet, the experimental animals (n = 6) were supplied with drinking water that was supplemented with 15% fructose. The control group (n = 6) was allowed access to normal rat chow, consisting of 35% carbohydrates, 30% protein, 15% fats, and 20% other components, as well as ordinary tap water. At the end of week 20, the experimental animals were diagnosed with prediabetes using the American Diabetes Association (ADA) prediabetes impaired fasting blood glucose criteria (5.6-6.9 mmol/L). Upon prediabetes diagnosis, the animals were subjected to a four-limb grip strength test to assess skeletal muscle strength at week 20. After the grip strength test was conducted, the animals were euthanized for blood and tissue collection to analyze glycated hemoglobin (HbA1c), plasma insulin, and insulin resistance using the homeostatic model of insulin resistance (HOMA-IR) index and malondialdehyde (MDA) concentration. Correlation analysis was performed to examine the associations of skeletal muscle strength with HOMA-IR, plasma glucose, HbA1c, and MDA concentration. The results demonstrated increased HbA1c, FBG, insulin, HOMA-IR, and MDA concentrations in the PD group compared to the NPD group. Grip strength was reduced in the PD group compared to the NPD group. Grip strength was negatively correlated with HbA1c, plasma glucose, HOMA-IR, and MDA concentration in the PD group. These observations suggest that diet-induced prediabetes compromises muscle function, which may contribute to increased levels of sedentary behavior during prediabetes progression, and this may contribute to the development of hyperglycemia in T2DM.
摘要：
2型糖尿病,糖尿病前期的情况，被证明会损害骨骼肌健康，从而影响骨骼肌结构，力量,和葡萄糖稳态。已证明骨骼肌功能能力的紊乱可诱导胰岛素抵抗和高血糖。然而,糖尿病前期骨骼肌功能的改变尚不清楚.因此，这项研究调查了在糖尿病前期模型中饮食诱导的糖尿病前期对骨骼肌力量的影响.将雄性SpragueDawley大鼠随机分配到两组中的一组（每组n=6；6名前糖尿病（PD）和6名非糖尿病前（NPD））。PD组（n=6）诱发糖尿病前期20周。用于诱发糖尿病前期的饮食由脂肪组成（30％Kcal/g），蛋白质（15%Kcal/g），和碳水化合物（55％千卡/克）。除了饮食,向实验动物(n=6)提供补充有15%果糖的饮用水。对照组（n=6）被允许进入正常的大鼠食物，由35%的碳水化合物组成，30%蛋白质,15%的脂肪，和20%的其他组件，以及普通的自来水。在第20周结束时,使用美国糖尿病协会(ADA)前驱糖尿病受损的空腹血糖标准(5.6-6.9mmol/L)将实验动物诊断为前驱糖尿病。在糖尿病前期诊断时，在第20周,对动物进行四肢握力测试,以评估骨骼肌力量.在进行抓握强度测试之后,对动物实施安乐死以收集血液和组织以分析糖化血红蛋白（HbA1c），血浆胰岛素，使用胰岛素抵抗（HOMA-IR）指数和丙二醛（MDA）浓度的稳态模型和胰岛素抵抗。进行相关性分析以检查骨骼肌力量与HOMA-IR，血浆葡萄糖，HbA1c,和MDA浓度。结果显示HbA1c升高，FBG,胰岛素，HOMA-IR,与NPD组相比，PD组的MDA浓度。与NPD组相比,PD组的握力降低。握力与HbA1c呈负相关,血浆葡萄糖，HOMA-IR,PD组MDA浓度。这些观察结果表明，饮食引起的糖尿病前期会损害肌肉功能，这可能会导致糖尿病前期进展期间久坐行为的增加，这可能有助于T2DM高血糖的发展。
