葡萄糖耐量正常或受损的绝经后女性的肌纤维特征

Muscle fiber characteristics in postmenopausal women with normal or impaired glucose tolerance.

作者信息

Larsson H, Daugaard J R, Kiens B, Richter E A, Ahrén B

机构信息

Department of Medicine, Malmö University Hospital, Sweden.

出版信息

Diabetes Care. 1999 Aug;22(8):1330-8. doi: 10.2337/diacare.22.8.1330.

DOI:10.2337/diacare.22.8.1330

PMID:10480779

Abstract

OBJECTIVE

Muscle fiber characteristics are altered in type 2 diabetes. We studied whether these alterations also exist in impaired glucose tolerance (IGT) and whether they are determinants of insulin sensitivity and glucose tolerance in postmenopausal women.

RESEARCH DESIGN AND METHODS

Percutaneous muscle biopsies from the vastus lateralis muscle were obtained from 77 postmenopausal women aged 57-59 years: 50 women with normal glucose tolerance (NGT) and 27 with IGT. The IGT group had a reduced insulin sensitivity compared with the NGT group (euglycemic-hyperinsulinemic clamp) (P = 0.003).

RESULTS

The groups did not differ in muscle fiber composition, as judged by the percentage of type I, IIa, or IIx fibers. In contrast, the IGT group had increased size of the IIa (mean +/-SD 3,776+/-987 vs. 3,078+/-862 microm2, P = 0.002) and IIx fibers (2,730+/-1,037 vs. 2,253+/-672 microm2, P = 0.017). There was a trend for the capillary diffusion areas (the muscle area supplied by each capillary) to be larger in the IGT group for the IIa (1,132+/-286 vs. 1,013+/-240 microm2, P = 0.061) and IIx fibers (1,020+/-246 vs. 906+/-240 microm2, P = 0.058). In the entire group, insulin sensitivity correlated with the size of the type IIa fibers (r = -0.28, P = 0.013), but not with the percentages of muscle fiber types. In a multiple regression, insulin sensitivity was determined by body fat content and HDL cholesterol level, while the size of the IIa fibers was not included in the model. Glucose tolerance was independently predicted by the number of capillaries/type I fiber, as well as by insulin sensitivity and triglyceride levels.

CONCLUSIONS

We conclude that although muscle fiber composition is not altered, women with IGT have larger type IIa and IIx muscle fibers and a trend for increased capillary diffusion areas for these fibers, compared with women with NGT. In the entire group, insulin sensitivity was determined mainly by body fat content, while muscle fiber capillarization may be of importance for glucose tolerance.

摘要

目的

2型糖尿病患者的肌纤维特征会发生改变。我们研究了这些改变在糖耐量受损（IGT）人群中是否也存在，以及它们是否是绝经后女性胰岛素敏感性和糖耐量的决定因素。

研究设计与方法

对77名年龄在57 - 59岁的绝经后女性进行了股外侧肌的经皮肌肉活检：50名糖耐量正常（NGT）女性和27名IGT女性。与NGT组相比，IGT组的胰岛素敏感性降低（正常血糖 - 高胰岛素钳夹试验）（P = 0.003）。

结果

根据I型、IIa型或IIx型纤维的百分比判断，两组在肌纤维组成上无差异。相比之下，IGT组的IIa型纤维（平均±标准差 3,776±987 vs. 3,078±862 μm²，P = 0.002）和IIx型纤维（2,730±1,037 vs. 2,253±672 μm²，P = 0.017）尺寸增大。IGT组的IIa型纤维（1,132±286 vs. 1,013±240 μm²，P = 0.061）和IIx型纤维（1,020±246 vs. 906±240 μm²，P = 0.058）的毛细血管扩散面积有增大趋势。在整个研究组中，胰岛素敏感性与IIa型纤维的尺寸相关（r = -0.28，P = 0.013），但与肌纤维类型的百分比无关。在多元回归分析中，胰岛素敏感性由体脂含量和高密度脂蛋白胆固醇水平决定，而IIa型纤维的尺寸未纳入该模型。糖耐量由毛细血管/ I型纤维数量、胰岛素敏感性和甘油三酯水平独立预测。