A Twin Study of Chronic Fatigue Syndrome in Sweden

尽管进行了大量研究，但有关慢性疲劳综合征的基本问题充其量也只能部分得到解答。这些问题包括它的定义、有效性、它在多大程度上是由遗传和环境因素造成的、与其他条件观察到的实质性共病的性质，以及女性占优势的基础。这个项目的首要目标是通过一项大规模的、基于人群的经典双胞胎研究来阐明一些关于慢性疲劳综合征的基本问题。首先，我们将收集大约32,000名年龄在42-65岁之间的成年人(13,000对完整的双胞胎)的数据，他们是基于人口的瑞典双胞胎登记处的成员，他们患有持续性疲劳、几种重叠的情况(纤维肌痛、肠易激综合征、紧张性头痛、过敏/湿疹、广泛性焦虑症和严重抑郁症)，以及详细的病史。其次，所有看起来患有CFS样疾病的双胞胎和部分CFS解释的双胞胎的医疗记录将通过一个高效的国家检索系统被请求。经过专家审查后，这些人将根据疾控中心的CFS标准进行分类。获得这些独特的数据将使我们能够解决有关CFS的一系列关键问题。首先，我们将在迄今研究的最大样本之一中估计CFS的患病率及其常见的合并症(纤维肌痛、肠易激综合征、紧张性头痛、过敏/湿疹、广泛性焦虑症和重度抑郁症)。其次，我们将使用各种多变量技术来推导出长期疲劳的经验类型，并评估该类型与CFS定义的比较。第三，我们将量化CFS及其共存条件的遗传和环境变异来源。第四，关键的是，我们将考察性别对这些变异来源的影响。最后，我们将使用多变量双生分析来分析CFS与纤维肌痛、肠易激综合征、紧张性头痛、过敏/湿疹、广泛性焦虑症和重度抑郁症之间的共病模式，从而估计共同的和独特的遗传和环境变异来源之间的重叠程度。与研究人员及其合作者正在进行的其他双胞胎研究相结合，我们希望通过在多个人群中进行平行研究，加快理解CFS病因的进展。目前的建议有几个独特的目标，并代表了一种具有成本效益的手段，以在流行病学样本中扩大这项工作，该样本可以说是世界上最好的孪生登记。

Despite considerable research, fundamental questions about CFS remain at best partially answered. These questions include its definition, validity, the degree to which it results from genetic versus environmental factors, the nature of the substantial comorbidity observed with other conditions, and the basis of the female preponderance. The overarching aim of this project is to shed light on a number of basic questions about CFS via a large, population-based classical twin study. First, we will collect data on approximately 32,000 adults aged 42-65 years (13,000 complete twin pairs) who are members of the population- based Swedish Twin Registry for persistent fatigue, several overlapping conditions (fibromyalgia, irritable bowel syndrome, tension headache, allergy/eczema, generalized anxiety disorder, and major depression), and a detailed medical history. Second, the medical records of all twins who appear to have CFS-like illness and a subset of those with "CFS-explained" will be requested via an efficient national retrieval system. Following expert review, these individuals will be classified in regard to the CDC CFS criteria. Obtaining these unique data will allow us to address a set of critical questions regarding CFS. First, we will estimate the prevalence of CFS and its common comorbidities (fibromyalgia, irritable bowel syndrome, tension headache, allergy/eczema, generalized anxiety disorder, and major depression) in one of the largest samples yet studied. Second, we will use a variety of multivariate techniques to derive an empirical typology of prolonged fatigue and to assess how this typology compares to the CFS definition. Third, we will quantify the genetic and environmental sources of variation for CFS and its comorbid conditions. Fourth, critically, we will examine the influence of gender on these sources of variation. Finally, we will analyze the patterns of comorbidity between CFS and fibromyalgia, irritable bowel syndrome, tension headache, allergy/eczema, generalized anxiety disorder, and major depression using multivariate twin analyses and thereby to estimate the extent of overlap between the shared and unique genetic and environmental sources of variation. In concert with other twin studies being conducted by the investigators and their collaborators, we hope to hasten progress in understanding the etiology of CFS by parallel studies in multiple populations. The current proposal has several unique aims and represents a cost-effective means to extend this work in an epidemiological sample that is arguably the best twin registry in the world.