Striated muscle fiber size, composition, and capillary density in diabetes in relation to neuropathy and muscle strength 糖尿病患者的横纹肌纤维尺寸、成份以及毛细血管密度与神经病变以及肌肉强度相关

Objective Diabetic polyneuropathy (DPN) leads to progressive loss of muscle strength in the lower extremities due to muscular atrophy. Changes in vascularization occur in diabetic striated muscle; however, the relationship between these changes and DPN is as yet unexplored. The aim of the present study was to evaluate histologic properties and capillarization of diabetic skeletal muscle in relation to DPN and muscle strength. Methods Twenty type 1 and 20 type 2 diabetic (T1D and T2D, respectively) patients underwent biopsy of the gastrocnemic muscle, isokinetic dynamometry at the ankle, electrophysiological studies, clinical examination, and quantitative sensory examinations. Muscle biopsies were stained immunohistochemically and muscle fiber diameter, fiber type distribution, and capillary density determined. Twenty control subjects were also included in the study. Results No relationship was found between muscle fiber diameter, muscle fiber type distribution, or capillary density and degree of neuropathy or muscle strength for either patient group. Muscle fiber diameter and the proportion of Type II fibers were greater for T1D patients than both T2D patients and controls. The T2D patients had fewer capillaries per muscle fiber than T1D patients and controls. Conclusions Striated muscle fiber size, muscle fiber distribution, and vascularization are unrelated to DPN and muscle strength in diabetes. 摘要 目的：糖尿病多发神经病变（Diabetic polyneuropathy，DPN）由于肌肉萎缩可导致下肢肌肉强度进行性地下降。糖尿病患者的横纹肌出现血管改变；然而，目前尚未有人研究这些变化与DPN之间的关系。本研究的目的是评估糖尿病患者骨骼肌的组织学特性和毛细血管与DPN和肌肉强度之间的关系。 方法：对20名1型糖尿病与2型糖尿病患者进行了腓肠肌活检、踝关节等速肌力测定、电生理学检查、临床检查以及定量感觉检查。对活检取得的肌肉样本进行了免疫组织化学染色并且测定了肌纤维直径、纤维型分布情况以及毛细血管密度。这项研究同时还入组了20名对照的受试者。 结果：在两组患者中，肌肉纤维直径、肌肉纤维型分布情况或毛细血管密度与神经病变的程度或肌肉强度之间都没有相关性。与2型糖尿病患者以及对照组相比，1型糖尿病患者的肌肉纤维直径以及II型纤维的比例都明显更大。与1型糖尿病患者以及对照组相比，2型糖尿病患者每根肌肉纤维中的毛细血管都更少。 结论：在糖尿病患者中，骨骼肌纤维尺寸、肌肉纤维分布情况和血管与DPN和肌肉强度都没有相关性。