Vollmer-Conna Uté, Aslakson Eric, White Peter D
University of New South Wales, School of Psychiatry, 30 Botany Street, Sydney UNSW 2052, Australia.
Pharmacogenomics. 2006 Apr;7(3):355-64. doi: 10.2217/14622416.7.3.355.
To test the hypothesis that medically unexplained chronic fatigue and chronic fatigue syndrome (CFS) are heterogeneous conditions, and to define the different conditions using both symptom and laboratory data.
We studied 159 women from KS, USA. A total of 51 of these suffered from fatigue consistent with established criteria for CFS, 55 had chronic fatigue of insufficient symptoms/severity for a CFS diagnosis and 53 were healthy controls matched by age and body mass index (BMI) against those with CFS. We used principal components analyses to define factors that best described the variable space and to reduce the number of variables. The 38 most explanatory variables were then used in latent class analyses to define discrete subject groups.
Principal components analyses defined six discrete factors that explained 40% of the variance. Latent class analyses provided several interpretable solutions with four, five and six classes. The four-class solution was statistically most convincing, but the six-class solution was more interpretable. Class 1 defined 41 (26%) subjects with obesity and relative sleep hypnoea. Class 2 were 38 (24%) healthy subjects. Class 3 captured 24 (15%) obese relatively hypnoeic subjects, but with low heart rate variability and cortisol. Class 4 were 23 (14%) sleep-disturbed and myalgic subjects without obesity or significant depression. The two remaining classes with 22 (14%) and 11 (7%) subjects consisted of the most symptomatic and depressed, but without obesity or hypnoea. Class 5 had normal sleep indices. Class 6 was characterized by disturbed sleep, with low sleep heart rate variability, cortisol, and sex hormones.
Chronic medically unexplained fatigue is heterogeneous. The putative syndromes were differentiated by obesity, sleep hypnoea, depression, physiological stress response, sleep disturbance, interoception and menopausal status. If these syndromes are externally validated and replicated, they may prove useful in determining the causes, pathophysiology and treatments of CFS.
检验医学上无法解释的慢性疲劳和慢性疲劳综合征（CFS）是异质性疾病这一假设，并使用症状和实验室数据来定义不同的疾病状态。
我们研究了来自美国堪萨斯州的159名女性。其中共有51人患有符合CFS既定标准的疲劳，55人有慢性疲劳，但症状/严重程度不足以诊断为CFS，53名健康对照者按年龄和体重指数（BMI）与CFS患者匹配。我们使用主成分分析来定义最能描述变量空间的因素，并减少变量数量。然后将38个最具解释力的变量用于潜在类别分析，以定义离散的受试者组。
主成分分析定义了六个离散因素，解释了40%的方差。潜在类别分析提供了几种可解释的解决方案，分为四类、五类和六类。四类解决方案在统计学上最有说服力，但六类解决方案更具可解释性。第1类定义了41名（26%）患有肥胖和相对睡眠呼吸暂停的受试者。第2类是38名（24%）健康受试者。第3类包括24名（15%）肥胖且相对呼吸不足的受试者，但心率变异性和皮质醇水平较低。第4类是23名（14%）睡眠障碍和肌痛的受试者，无肥胖或明显抑郁。其余两类分别有22名（14%）和11名（7%）受试者，由症状最明显和抑郁程度最高的人组成，但无肥胖或呼吸暂停。第5类睡眠指数正常。第6类的特征是睡眠障碍，睡眠心率变异性、皮质醇和性激素水平较低。
医学上无法解释的慢性疲劳是异质性的。假定的综合征通过肥胖、睡眠呼吸暂停、抑郁、生理应激反应、睡眠障碍、内感受和绝经状态来区分。如果这些综合征能够得到外部验证和重复验证，它们可能有助于确定CFS的病因、病理生理学和治疗方法。
