Effects of exercise training on insulin-like growth factor-I expression in the skeletal muscle of non-cachectic patients with chronic heart failure
Effects of exercise training on insulin-like growth factor-I expression in the skeletal muscle of non-cachectic patients with chronic heart failure
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DOI：
10.1097/01.hjr.0000173106.68485.b7
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发表时间：
2005-08-01
影响因子：
--
通讯作者：
Schuler, G
中科院分区：
文献类型：
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作者：
Hambrecht, R;Schulze, PC;Schuler, G
背景慢性心力衰竭(CHF)与进行性肌肉萎缩和局部胰岛素样生长因子-I(IGF-I)表达减少有关。设计本研究旨在验证CHF患者骨骼肌局部IGF-I缺乏对6个月有氧训练干预的反应的假说。因此，18例患者[平均年龄52.4(SD 4.8)岁，左心室射血功能(LVEF)27(SD 6)%]前瞻性随机分为6个月训练组和静坐组。方法采用免疫荧光法测定血清生长激素(GH)水平，竞争固相免疫法测定血清IGF-I水平。结果运动训练使股外侧肌最大摄氧量增加26%[从20.3ml/kg/min增加到25.5ml/kg/min，P=0.003]。运动训练后局部胰岛素样生长因子-I的表达显著增加[与对照组比较，从6.3SE0.8个相对单位增加到11.4SE1.4个相对单位，P=0.007]，而IGFI受体的表达降低了33%[从20.0SE2-1个相对单位到13.8SE1.7个相对单位，P=0.008]。训练组血清生长激素(GH)从0.12(SE0.07)至0.65(SE0.37)ng/ml略有上升(与基线比较P=0.043)，但与对照组相比变化不显著(P=0.848)。结论运动训练可提高局部LGF-I的表达，而对GH/IGF-I轴的系统参数无明显影响。这些发现表明，运动训练具有减轻周围骨骼肌改变的治疗潜力，尤其是在中度CHF患者的局部IGF-I表达方面。
Background Chronic heart failure (CHF) is associated with progressive muscle atrophy and reduced local expression of insulin-like growth factor I (IGF-I).Design The present study was designed to test the hypothesis that the local deficiency of IGF-I in the skeletal muscle of patients with CHF would respond to a 6-months aerobic training intervention. Therefore, 18 patients [mean age 52.4 (SD 4.8) years, left ventricular ejection function (LVEF) 27 (SD 6)%] were prospectively randomized to either 6 months of training or sedentary lifestyle.Methods Serum levels of growth hormone (GH) were measured by immunofluorometric assay, IGF-I by competitive solid phase immunoassay. IGF-I expression was assessed in vastus lateralis biopsies by real-time PCR.Results Exercise training led to a significant increase in peak oxygen uptake by 26% [from 20.3 (SD 3.3) ml/kg per min to 25.5 (SD 5.7)ml/kg per min, P = 0.003 versus control]. Local expression of IGF-I increased significantly after exercise training by 81% [from 6.3 (SE 0.8) to 11.4 (SE 1.4) relative units, P = 0.007 versus control] while IGF-I receptor expression was reduced by 33% [from 20.0 (SE 2-1) to 13.8 (SE 1.7) relative units, P = 0.008 versus control]. Serum growth hormone (GH) rose modestly from 0.12 (SE 0.07) to 0.65 (SE 0.37) ng/ml in the training group (P = 0.043 versus baseline), however, this change was not significant compared to the control group (P = 0.848). IGF-I serum levels remained virtually unchanged.Conclusions Exercise training improves local lGF-I expression without significant changes of systemic parameters of the GH/IGF-I axis. These findings indicate that exercise training has the therapeutic potential to attenuate peripheral skeletal muscle alterations in particular with respect to local IGF-I expression in patients with moderate CHF.