OBJECTIVE Insulin increases glucose disposal in part by enhancing microvascular blood flow (MBF) and substrate delivery to myocytes. Insulin’s microvascular action is impaired with insulin resistance and type 2 diabetes. Resistance training (RT) improves glycemic control and insulin sensitivity, but whether this improvement is linked to augmented skeletal muscle microvascular responses in type 2 diabetes is unknown.

RESEARCH DESIGN AND METHODS Seventeen (11 male and 6 female; 52 ± 2 years old) sedentary patients with type 2 diabetes underwent 6 weeks of whole-body RT. Before and after RT, participants who fasted overnight had clinical chemistries measured (lipids, glucose, HbA_1c, insulin, and advanced glycation end products) and underwent an oral glucose challenge (OGC) (50 g × 2 h). Forearm muscle MBF was assessed by contrast-enhanced ultrasound, skin MBF by laser Doppler flowmetry, and brachial artery flow by Doppler ultrasound at baseline and 60 min post-OGC. A whole-body DEXA scan before and after RT assessed body composition.

RESULTS After RT, muscle MBF response to the OGC increased, while skin microvascular responses were unchanged. These microvascular adaptations were accompanied by improved glycemic control (fasting blood glucose, HbA_1c, and glucose area under the curve [AUC] during OGC) and increased lean body mass and reductions in fasting plasma triglyceride, total cholesterol, advanced glycation end products, and total body fat. Changes in muscle MBF response after RT significantly correlated with reductions in fasting blood glucose, HbA_1c, and OGC AUC with adjustment for age, sex, % body fat, and % lean mass.

CONCLUSIONS RT improves OGC-stimulated muscle MBF and glycemic control concomitantly, suggesting that MBF plays a role in improved glycemic control from RT.

目的胰岛素通过增加微血管血流量（MBF）和向肌细胞的底物传递来部分增加葡萄糖的处置。胰岛素抵抗和2型糖尿病会损害胰岛素的微血管作用。抵抗训练（RT）可以改善血糖控制和胰岛素敏感性，但是这种改善是否与2型糖尿病患者骨骼肌微血管反应增强有关。

研究设计和方法17例（11例男性和6例女性； 52±2岁）久坐的2型糖尿病患者接受了6周的全身RT。在放疗前后，对禁食过夜的参与者进行了临床化学检测（脂质，葡萄糖，HbA _1c，胰岛素和晚期糖基化终产物），并进行了口服葡萄糖激发（OGC）（50 g×2 h）。在基线和OGC后60分钟，通过对比增强超声评估前臂MBF，通过激光多普勒血流仪评估皮肤MBF，并通过多普勒超声评估肱动脉血流。RT之前和之后的全身DEXA扫描评估了身体成分。

结果放疗后，肌肉对OGC的MBF反应增加，而皮肤微血管反应未改变。这些微血管适应性改善了血糖控制（在OGC期间空腹血糖，HbA _1c和曲线[AUC]下的葡萄糖面积）并增加了瘦体重并降低了空腹血浆甘油三酸酯，总胆固醇，晚期糖基化终产物和体内总脂肪。RT后肌肉MBF反应的变化与空腹血糖，HbA _1c和OGC AUC的降低显着相关，并可以调整年龄，性别，％体脂和瘦肉率。

结论RT可以同时改善OGC刺激的肌肉MBF和血糖控制，提示MBF可以改善RT的血糖控制。