EXERCISE INTOLERANCE IN CHRONIC FATIGUE SYNDROME

尽管各种客观的临床和实验室异常 在慢性疲劳综合征（CFS）的报告，也没有 对符合当前标准的所有患者敏感或特异 案例定义。 急性运动试验同样产生了一系列 的发现。 然而，患者的反应非常一致， 抱怨轻微的用力会导致 症状持续数天。了解这种现象的基础， 有助于理解CFS的发病机制，也可能 提供对其他疾病中主观疲劳性质的深入了解 states. 在正常受试者中，心脏、血管、排泄和代谢 严格控制对运动的调整以维持体内平衡 关键功能。 高强度的运动伴随着 急性应激反应，包括非特异性标志物的变化 然而，当免疫激活时， 练习结束。 考虑到内分泌系统之间的相互作用， 免疫系统和自主神经系统的反应， 运动，假设其中一个或多个是不好的， 在CFS患者中进行调节。为了支持这一前提， 的CFS患者在各种研究中报告有：异常 对运动的心血管反应，皮质醇产生减少， 和细胞因子水平升高。急性反应的初步研究 CFS患者的运动表现出异常，提示 改变的心血管反应提示 血管调节，改变肌肉生物能量学，或可能严重 去适应 这些数据被用来设计研究方案， 慢性疲劳综合征中的运动不耐受 具体目标包括： 1)确定预测运动能力下降的临床特征 在CFS中，2）评估心血管反应的动态控制， 运动能力异常的CFS患者的亚极量运动，3） 确定CFS患者的肌肉工作效率，以及4）测试CFS患者的肌肉工作效率。 假设夸大或延长体液或炎症 CFS患者的急性运动反应，延迟了 恢复体内平衡

Although a variety of objective clinical and laboratory abnormalities have been reported in Chronic Fatigue Syndrome (CFS), none is either sensitive or specific for all patients fulfilling the current criteria for case definition. Acute exercise testing likewise yields a spectrum of findings. Remarkably consistent, however, are the patients' complaints that minor amounts of exertion lead to exacerbation of symptoms for periods of days. Knowing the basis for this phenomena would contribute to understanding the pathogenesis of CFS, and might also provide insight into the nature of subjective fatigue in other disease states. In normal subjects, cardiac, vascular, ventilatory and metabolic adjustments to exercise are tightly controlled to maintain homeostasis of critical functions. While high intensity exercise is accompanied by an acute stress response, including changes in markers of non-specific immune activation, homeostasis must nevertheless be reestablished when exercise ends. Given the interactions between the endocrine, immunologic, and autonomic nervous system responses activated during exercise, it is hypothesized that one of more of these is poorly regulated in patients with CFS. In support of this premise, proportions of CFS patients in various studies are reported to have: abnormal cardiocirculatory responses to exercise, decreased cortisol production, and increased levels of cytokines. Preliminary studies of acute responses to exercise in CFS patients demonstrated abnormalities suggestive of altered cardiovascular responses suggestive of either impaired vasoregulation, altered muscle bioenergetics, or perhaps severe deconditioning. These data were used to design protocols to investigate exercise intolerance in chronic fatigue syndrome. Specific aims include: 1) identifying clinical features predicting decreased exercise capacity in CFS, 2) assessing the dynamic control of cardiovascular response to submaximal exercise in CFS patients with abnormal exercise capacity, 3) determining muscular work efficiency in CFS patients, and 4) testing the hypothesis that exaggerated or prolonged humoral or inflammatory responses accompany acute exercise in patients with CFS, delaying the return to homeostasis.