Straczkowski M, Kowalska I, Dzienis-Straczkowska S, Stepién A, Skibińska E, Szelachowska M, Kinalska I
Department of Endocrinology, Medical Academy, M.C. Sklodowskiej 24a, 15-276 Bialystok, Poland.
Eur J Endocrinol. 2001 Sep;145(3):273-80. doi: 10.1530/eje.0.1450273.
Tumor necrosis factor-alpha (TNFalpha) plays an important role in the pathogenesis of insulin resistance and type 2 diabetes. Plasma levels of the soluble (s) fractions of TNFalpha receptors, especially sTNFR2, are good indicators of TNFalpha system activation in obesity. The aim of the present study was to assess the effect of exercise training on the TNFalpha system and to evaluate the relationship with changes in insulin sensitivity.
Sixteen obese women (body mass index (BMI)>27.8 kg/m(2)), 8 with normal (NGT) and 8 with impaired glucose tolerance (IGT), participated in an exercise training program which lasted for 12 weeks and included exercise performed on a bicycle ergometer at an individual intensity of 70% maximal heart rate, for 30 min, 5 days a week. Anthropometrical measurements and blood biochemical analyses were performed, and plasma TNFalpha, sTNFR1 and sTNFR2 levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique (insulin infusion: 50 mU x kg(-1)xh(-1)).
At baseline, despite similar anthropometrical parameters, IGT subjects were markedly more insulin resistant and had higher TNFalpha and sTNFR2 concentrations. Exercise training increased insulin sensitivity and decreased TNFalpha and sTNFR2 levels, while sTNFR1 remained unchanged. The decrease in sTNFR2 was significantly related to the increase in insulin sensitivity; that relationship remained significant after adjustment for the concurrent changes in BMI, waist circumference, percentage of body fat, plasma glucose, insulin and free fatty acids.
Regular physical exercise decreases TNFalpha system activity and that decrease may be responsible for the concurrent increase in insulin sensitivity.
肿瘤坏死因子-α（TNFα）在胰岛素抵抗和2型糖尿病的发病机制中起重要作用。TNFα受体可溶性（s）组分的血浆水平，尤其是sTNFR2，是肥胖中TNFα系统激活的良好指标。本研究的目的是评估运动训练对TNFα系统的影响，并评估其与胰岛素敏感性变化的关系。
16名肥胖女性（体重指数（BMI）>27.8 kg/m²），8名糖耐量正常（NGT），8名糖耐量受损（IGT），参加了一项为期12周的运动训练计划，包括在自行车测力计上以个人最大心率的70%强度进行运动，每次30分钟，每周5天。进行人体测量和血液生化分析，并评估血浆TNFα、sTNFR1和sTNFR2水平。使用高胰岛素正常血糖钳夹技术（胰岛素输注：50 mU·kg⁻¹·h⁻¹）评估胰岛素敏感性。
在基线时，尽管人体测量参数相似，但IGT受试者的胰岛素抵抗明显更强，TNFα和sTNFR2浓度更高。运动训练提高了胰岛素敏感性，降低了TNFα和sTNFR2水平，而sTNFR1保持不变。sTNFR2的降低与胰岛素敏感性的增加显著相关；在对BMI、腰围、体脂百分比、血浆葡萄糖、胰岛素和游离脂肪酸的同时变化进行调整后，这种关系仍然显著。
规律的体育锻炼可降低TNFα系统活性，这种降低可能是胰岛素敏感性同时增加的原因。
