Prevalence Of Chronic Fatigue Syndrome Research Articles

Chronic Fatigue Syndrome Prevalence and its Relation to Job Performance among Nurses

Background and Objectives: Chronic Fatigue Syndrome (CFS) is a severe, debilitating disorder. Permanent chronic fatigue that affects the daily routine activities at least for six months and4 of the 8 patients reported symptoms associated with this disorder (problems of memory / concentration, restless sleep, joint pain, swollen lymph nodes, muscle pain, headache, sore throat, weakness due to work) and the absence of any underlying disease is the another sign of this disorder. One of the important things that are noticeable about the syndrome, is causing physical and mental disabilities in the person that will lead to approximately 50% reduction in his job performance. Methods: This study has been conducted through self-reported questionnaire and field and library studies. So the desired randomly set of 78 nurses have been selected to answer the two demographic information and symptoms questionnaires CFS (DSQ. revised)which it's reliability and validity has been verified. These questionnaires have been adjusted to the patient's preliminary data record and their symptoms. In the second stage, each individual job performance questionnaire was completed by department head. Results: The information obtained from the chronic fatigue syndrome questionnaire shows 14.1% prevalence of CFS. In discussing the relationship between CFS and indicators of job performance, it was cleared that people with the syndrome has lower job performance than those are healthy. Conclusions: In many similar studies, the effects of CFS on overall job performance in subjects were discussed and in most cases have been verified. The only differences are in subdivisions of job performance which are considered in this research

Chronic fatigue syndrome in middle-aged women: the role of disorders of glucose metabolism

Objectives: To determine the prevalence of chronic fatigue syndrome (CFS) among middle-aged women and to assess the role of glucose metabolism disturbances in the development of this pathology. Materials and Methods: The study included 231 women from 40 to 60 years old (mean age 52.3 ± 5 years), observed at urban polyclinic in Moscow, who was referred to or was observed by an endocrinologist (n = 142, group 1), therapist (n = 56, group 2) or had a prophylactic medical examinations (n = 33, group 3). We recorded demographic and anthropometric data, accessed levels of glucose, glycated hemoglobin, insulin and calculated BMI and HOMA indexes. Results: The prevalence of CFS in the whole group of patients studied was 27%. The highest frequency of CFS is registered in the group of patients observed by the endocrinologist – 35%, and at dispensary examination – 21%, which was significantly different from the prevalence of CFS in patients seeking an appointment with a therapist – 13% (p = 0.002 and p = 0.03 for Fisher's exact test, respectively). Higher BMI, blood glucose, glycosylated hemoglobin, and HOMA insulin resistance index as naturally expected were observed in group 1, but after further division for the presence or absence of CFS, significant differences for patients with CFS were only higher fasting glucose levels in group 2. Conclusions: We determined the prevalence of CFS in the examined groups of patients and showed only a weak correlation of CFS and disturbances of glucose metabolism.

Prevalence, Health Care Utilization, and Costs of Fibromyalgia, Irritable Bowel, and Chronic Fatigue Syndromes in the Military Health System, 2006–2010

We compared prevalence, health care utilization, and costs over time for nonelderly adults diagnosed with fibromyalgia syndrome (FMS), irritable bowel syndrome (IBS), and chronic fatigue syndrome (CFS) in relation to timing of federal approvals for FMS drugs. We used military health care claims from October 2006 to September 2010. Retrospective, multiple-year comparisons were conducted using trend analyses, and time series regression-based generalized linear models. Over 5 years, FMS prevalence rates increased from 0.307% to 0.522%, whereas IBS and CFS prevalence rates remained stable. The largest increase in FMS prevalence occurred between 2007 and 2008. Health care utilization was higher for FMS cases compared to IBS and CFS cases. Over 5 years, the total cost for FMS-related care increased $163.2 million, whereas IBS costs increased $14.9 million and CFS cost increased $3.7 million. Between 2006 and 2010, total pharmacy cost for FMS cases increased from $55 million ($3,641/person) to $96.3 million ($3,557/person). Although cause and effect cannot be established, the advent of federally approved drugs for FMS in concert with pharmaceutical industry marketing of these drugs coincide with the observed changes in prevalence, health care utilization, and costs of FMS relative to IBS and CFS.

Syndrome de Fatigue Chronique : une entité à part entière ?

BackgroundAlthough a lot of multidisciplinary literature is available about the Chronic Fatigue Syndrome, the existence of the disorder is still questioned. The process leading to the clinical description of Chronic Fatigue Syndrome was slow. Indeed, sporadic Chronic Fatigue Syndrome-like cases were first described in the 19th and 20th centuries. In the 1950s, Myalgic Encephalomyelitis was described after an outbreak of neurological symptoms at the Royal Free Hospital in London. Myalgic Encephalomyelitis was finally renamed “Chronic Fatigue Syndrome” in 1988. The Chronic Fatigue Syndrome was described as a condition mainly characterized by debilitating, persistent or recurrent fatigue over six months and associated with other related symptoms, and inducing a significant distress or impairment in social, occupational or other important areas of functioning. To date, patients prefer the term “Myalgic Encephalomyelitis” because “Chronic Fatigue Syndrome” seems too much stigmatizing. Definition and international classificationsIn 1994, a consensus was reached on a case definition from the United States Center for Disease Control and Prevention. The International Classification of Diseases, tenth revision, classifies the Chronic Fatigue Syndrome in the category “disorders of the nervous system”. The Diagnostic and Statistical Manual, fourth and fifth versions, do not include this disorder in their classification. EpidemiologyAccording to the United States Center for Disease Control and Prevention definition, the prevalence of Chronic Fatigue Syndrome varies from 0.4 % to more than 2 %. The sex ratio for Chronic Fatigue Syndrome is 3/1 with a higher prevalence in women, particularly between 40 and 49 years old. These epidemiological points are consistent with an anxious or depressive nature. Chronic Fatigue Syndrome symptomatology and anxio-depressive symptomatologyAlthough Chronic Fatigue Syndrome and anxio-depressive disorders have common symptoms (cognitive disorders, asthenia, headaches and sleep disorders), others (tender lymph nodes, sore throat, post-exertional malaise, the absence of pathological mood) are not coherent with the spectrum of depression or anxiety disorders. ComorbiditiesThere is a high prevalence of major depressive disorders, bipolar disorders and personality disorders among subjects with Chronic Fatigue Syndrome. PhysiopathologySome results support a genetic predisposition to the Chronic Fatigue Syndrome, polymorphisms of genes involved in the monoaminergic system being implicated. Neuroimaging studies have shown structural and functional changes in the central nervous system of patients with a Chronic Fatigue Syndrome. These changes are compatible with those observed in anxio-depressive disorders. A central nervous system up-regulation of the serotoninergic system and a low circulating cortisol were also reported in Chronic Fatigue Syndromes whereas there is a down-regulation of this system in major depressive disorders. Several microbian microorganisms have been implicated but their pathogenic relationship with the syndrome has not been demonstrated yet. Particularly, the viral implication was recently overturned. Several immune abnormalities, similar at those shown in major depressive disorders, have also been shown in CFS patients but there is no scientific evidence that they have a causal role in Chronic Fatigue Syndromes. Healthcare managementNo pharmacological treatment, in particular no antidepressant drug, has demonstrated a positive benefit/risk ratio in the treatment of CFS. Cognitive behavior therapy and Graded exercise therapy could improve the Chronic Fatigue Syndrome outcome. ConclusionThe Chronic Fatigue Syndrome is still a controversial disorder, which remains an exclusion diagnosis. Despite its common features and comorbidity with anxio-depressive disorders, the CFS seems to be an independent disease. Further studies are needed to elucidate the etiology and find the optimal treatment of this syndrome.

Clinical Practice: Chronic fatigue syndrome

The diagnosis chronic fatigue syndrome (CFS) was conceptualized in the mid-1980s. It is a clinically defined condition characterized by severe and disabling new onset fatigue with at least four additional symptoms: impaired memory or concentration, sore throat, tender cervical or axillary lymph nodes, muscle pain, multi-joint pain, new headaches, unrefreshing sleep or post-exertion malaise. Chronic fatigue syndrome in adolescents is a rare condition compared to symptomatic fatigue. The estimated prevalence of adolescent CFS ranges between 0.11 and 1.29 % in Dutch, British, and US populations. Diagnosis of the chronic fatigue syndrome is established through exclusion of other medical and psychiatric causes of chronic fatiguing illness. Taking a full clinical history and a full physical examination are therefore vital. In adolescence, CFS is associated with considerable school absence with long-term detrimental effects on academic and social development. One of the most successful potential treatments for adolescents with CFS is cognitive behavioural therapy, which has been shown to be effective after 6 months in two thirds of the adolescents with CFS. This treatment effect sustains at 2-3-year follow-up. In conclusion, the diagnosis CFS should be considered in any adolescent patient with severe disabling long-lasting fatigue. Cognitive behavioural therapy is effective in 60-70 % of the patients. Prompt diagnosis favours the prognosis.

The prevalence of chronic fatigue syndrome/ myalgic encephalomyelitis: a meta-analysis

PurposeTo perform a meta-analysis to examine variability among prevalence estimates for CFS/ME, according to the method of assessment used.MethodsDatabases were systematically searched for studies on CFS/ME prevalence in adults that applied the 1994 Centers for Disease Control (CDC) case definition.1 Estimates were categorized into two methods of assessment: self-reporting of symptoms versus clinical assessment of symptoms. Meta-analysis was performed to pool prevalences by assessment using random effects modeling. This was stratified by sample setting (community or primary care) and heterogeneity was examined using the I2 statistic.ResultsOf 216 records found, 14 studies were considered suitable for inclusion. The pooled prevalence for self-reporting assessment was 3.28% (95% CI: 2.24–4.33) and 0.76% (95% CI: 0.23–1.29) for clinical assessment. High variability was observed among self-reported estimates, while clinically assessed estimates showed greater consistency.ConclusionThe observed heterogeneity in CFS/ME prevalence may be due to differences in method of assessment. Stakeholders should be cautious of prevalence determined by the self-reporting of symptoms alone. The 1994 CDC case definition appeared to be the most reliable clinical assessment tool available at the time of these studies. Improving clinical case definitions and their adoption internationally will enable better comparisons of findings and inform health systems about the true burden of CFS/ME.

Prevalence, Incidence, and Classification of Chronic Fatigue Syndrome in Olmsted County, Minnesota, as Estimated Using the Rochester Epidemiology Project

ObjectiveTo estimate the prevalence and incidence of chronic fatigue syndrome in Olmsted County, Minnesota, using the 1994 case definition and describe exclusionary and comorbid conditions observed in patients who presented for evaluation of long-standing fatigue. Patients and MethodsWe conducted a retrospective medical record review of potential cases of chronic fatigue syndrome identified from January 1, 1998, through December 31, 2002, using the Rochester Epidemiology Project, a population-based database. Patients were classified as having chronic fatigue syndrome if the medical record review documented fatigue of 6 months' duration, at least 4 of 8 chronic fatigue syndrome–defining symptoms, and symptoms that interfered with daily work or activities. Patients not meeting all of the criteria were classified as having insufficient/idiopathic fatigue. ResultsWe identified 686 potential patients with chronic fatigue, 2 of whom declined consent for medical record review. Of the remaining 684 patients, 151 (22%) met criteria for chronic fatigue syndrome or insufficient/idiopathic fatigue. The overall prevalence and incidence of chronic fatigue syndrome and insufficient/idiopathic fatigue were 71.34 per 100,000 persons and 13.16 per 100,000 person-years vs 73.70 per 100,000 persons and 13.58 per 100,000 person-years, respectively. The potential cases included 482 patients (70%) who had an exclusionary condition, and almost half the patients who met either criterion had at least one nonexclusionary comorbid condition. ConclusionThe incidence and prevalence of chronic fatigue syndrome and insufficient/idiopathic fatigue are relatively low in Olmsted County. Careful clinical evaluation to identify whether fatigue could be attributed to exclusionary or comorbid conditions rather than chronic fatigue syndrome itself will ensure appropriate assessment for patients without chronic fatigue syndrome.

Influence of social and demographic factors on clinical status and severity of chronic fatigue syndrome in patients with multiple sclerosis

Introduction. Chronic fatigue syndrome (CFS) is cha-racterized by apathy, indifference, exhaustion, and lack of energy, and these symptoms are not the result of intense physical or mental work. Chronic fatigue syndrome often accompanies patients with multiple sclerosis (MS). Aim. The aim of this study was to assess the impact of social and demographic factors on clinical status and level of chronic fatigue syndrome in patients with MS. Material and methods. The study group comprised 33 MS patients who were treated at the Department of Rehabilitation and Department of Neurology with the Stroke Treatment Unit from November 20, 2010 to 27 April 2011. The research applied a questionnaire containing social and demographic data and the Barthel Scale, Beck’s Depression Inventory (BDI), the Kurtzke Scale and the Fatigue Severity Scale. The results were analyzed statistically using descriptive statistics and Spearman’s rank correlation coefficient. Results. Statistically significant correlations were confirmed between functional status assessed in the Barthel scale and subjects’ age, disease duration, and the results in the Kurtzke Scale. No statistically significant relationship between the BDI and the analyzed factors was obtained. Significant statistical correlation was obtained between the scores obtained in the Fatigue Severity Scale and family status in the study group. There was also found a weak correlation between the results in the Barthel Scale and Beck Depression Inventory and scores in the Fatigue Severity Scale. Conclusions. A significant statistical correlation was confirmed between the results on Fatigue Severity Scale and family status, occurring depression and functional capacity in carrying out activities of daily living. There was no statistically significant correlation between such factors as gender, place of residence, education, faith, disease duration and prevalence of chronic fatigue syndrome in patients with MS.

Chronic fatigue syndrome and subsequent risk of cancer among elderly US adults

The cause of chronic fatigue syndrome (CFS) is unknown but is thought to be associated with immune abnormalities or infection. Because cancer can arise from similar conditions, associations between CFS and cancer were examined in a population-based case-control study among the US elderly. Using linked Surveillance, Epidemiology, and End Results (SEER)-Medicare registry data, approximately 1.2 million cancer cases and 100,000 controls (age range, 66-99 years; 1992-2005) were evaluated. CFS was identified in the period more than 1 year prior to selection, using linked Medicare claims. Unconditional logistic regression was used to estimate the odds ratios (ORs) comparing the CFS prevalence in cases and controls, adjusting for age, sex, and selection year. All statistical tests were 2-sided. CFS was present in 0.5% of cancer cases overall and 0.5% of controls. CFS was associated with an increased risk of non-Hodgkin lymphoma (NHL) (OR = 1.29, 95% confidence interval [CI] = 1.16-1.43, P = 1.7 × 10(-6) ). Among NHL subtypes, CFS was associated with diffuse large B cell lymphoma (OR = 1.34, 95% CI = 1.12-1.61), marginal zone lymphoma (OR = 1.88, 95% CI = 1.38-2.57), and B cell NHL not otherwise specified (OR = 1.51, 95% CI = 1.03-2.23). CFS associations with NHL overall and NHL subtypes remained elevated after excluding patients with medical conditions related to CFS or NHL, such as autoimmune conditions. CFS was also associated, although not after multiple comparison adjustment, with cancers of the pancreas (OR = 1.25, 95% CI = 1.07-1.47), kidney (OR = 1.27, 95% CI = 1.07-1.49), breast (OR = 0.85, 95% CI = 0.74-0.98), and oral cavity and pharynx (OR = 0.70, 95% CI = 0.49-1.00). Chronic immune activation or an infection associated with CFS may play a role in explaining the increased risk of NHL.

Are fatigue symptoms and chronic fatigue syndrome following Q fever infection related to psychosocial variables?

ObjectiveFatigue is known as one of the most common long-term sequelae of Q fever infections. The study aimed to determine the prevalence of fatigue symptoms, chronic fatigue, and chronic fatigue syndrome (CFS) in a sample of patients who were exposed to Q fever (Coxiella burnetii) infection compared to controls, and to contrast Q fever patients with and without fatigue symptoms related to somatoform symptoms, hypochondriacal worries and beliefs, psychosocial complaints, and social support. MethodsCross-sectional study of 84 Q fever exposed patients from a specific region in Jena (Germany) and 85 matched controls using standardized questionnaires (MFI, SF-12, CDC-SI, SOMS, Whiteley Index, OQ-45 and F-Sozu). Diagnostic interviews were performed to validate questionnaire results in a smaller subsample. ResultsPatients who were exposed to a Q fever infection in the past indicated more fatigue symptoms and chronic fatigue than controls (54.8 vs. 20%, 32.1 vs. 4.7%) but did not show more criteria for a CFS (1 patient in each group). Q fever patients showing fatigue symptoms revealed significantly higher scores in the SOMS, the Whiteley-Index, and higher psychosocial complaints measured with the OQ-45. Their health related Quality of Life was reduced, no differences were found related to perceived social support. ConclusionAlthough in our sample fatigue symptoms were common among Q fever patients, we found no increased prevalence of CFS in contrast to several other studies. The combination of fatigue symptoms with other psychosocial symptoms/problems support the view of a biopsychosocial etiology of fatigue symptoms.

The Comorbidity of Self-Reported Chronic Fatigue Syndrome, Post-Traumatic Stress Disorder, and Traumatic Symptoms

Data from primary care and community samples suggest higher rates of post-traumatic stress disorder (PTSD) among individuals with chronic fatigue syndrome (CFS). This study investigated the co-occurrence of CFS, PTSD, and trauma symptoms and assessed the contribution of familial factors to the association of CFS with lifetime PTSD and current traumatic symptoms. Data on lifetime CFS and PTSD, as measured by self-report of a doctor's diagnosis of the disorder, and standardized questionnaire data on traumatic symptoms, using the Impact of Events Scale (IES), were obtained from 8544 female and male twins from the community-based University of Washington Twin Registry. Lifetime prevalence of CFS was 2% and lifetime prevalence of PTSD was 4%. Participants who reported a history of PTSD were over eight times more likely to report a history of CFS. Participants with scores ≥ 26 on the IES were over four times more likely to report CFS than those who had scores ≤ 25. These associations were attenuated but remained significant after adjusting for familial factors through within-twin pair analyses. These results support similar findings that a lifetime diagnosis of CFS is strongly associated with both lifetime PTSD and current traumatic symptoms, although familial factors, such as shared genetic and environmental contributions, played a limited role in the relationship between CFS, PTSD, and traumatic symptoms. These findings suggest that future research should investigate both the familial and the unique environmental factors that may give rise to both CFS and PTSD.

Síndrome de fatiga crónica: estudio de una serie consecutiva de 824 casos evaluados en dos unidades especializadas

Background and objective The chronic fatigue syndrome (CFS) is a disabling disorder. Few studies are available in our area on the prevalence and characteristics of CFS. Therefore, we carried out a study of a consecutive series of 824 cases diagnosed in two specialized units. Patients and methods We evaluated all of the CFS patients seen from January 2008 to June 2010. We analyzed social and demographic data, employment status, time of clinical evolution, trigger factors and onset, Fukuda and Canadian criteria, associated comorbidities and treatment. Results A total of 824 patients were included, 748 (91%) woman, mean age 48 ± 9 years. Average age of onset of symptoms was 35 ± 11 years, time to diagnosis 108 ± 88 month. A precipitating factor was identified in 481 (58%) patients, the onset was gradual in 517 (63%) and 515 (62.5%) were not employed. The most outstanding diagnostic criteria of Fukuda were prolonged generalized fatigue after exercise, sleep disturbance and impairments in concentration and short-term memory. The different groups of symptoms defined by the Canadian consensus showed that CFS is a homogeneous entity. Accompanying comorbidity phenomena were anxiety 691 (83%), sicca syndrome 678 (82%), fibromyalgia 450 (55%). A total of 63% of patients (520) received pharmacological treatment. Conclusions CFS is an illness that preferentially affects young women and results in employment absenteeism. The most relevant clinical features were prolonged generalized fatigue after exercise, neurocognitive impairment and sleep disturbance. In the evaluation of the patient, it is very important to apply the Canadian criteria and to assess comorbidity.

Demographic and clinical aspects of an Italian patient population with chronic fatigue syndrome

The purpose of this study was to investigate demographic and clinical aspects of a group of Italian patients with Chronic Fatigue Syndrome (CFS) which have not yet been described, in order to compare them with International literature, and to better define certain clinical aspects of the syndrome with respect to the Fukuda et al. case definition. A detailed questionnaire was sent to patients with certified CFS diagnosed in a referral center and the data were collected two weeks later. Besides persistent fatigue, a clinical syndrome with infectious, neurological and rheumatological characteristics is outlined from the data. Demographic characteristics of Italian patients are very similar to those described in international literature. Therapy has yet to be validated with evidence-based studies in Italy. Studies on the prevalence of CFS in Italy are lacking and would be useful to better define the syndrome in this Mediterranean population.

Adolescent Chronic Fatigue Syndrome: Prevalence, Incidence, and Morbidity

To determine nationwide general practitioner (GP)-diagnosed prevalence and pediatrician-diagnosed incidence rates of adolescent chronic fatigue syndrome (CFS), and to assess CFS morbidity. We collected data from a cross-sectional national sample among GPs and prospective registration of new patients with CFS in all pediatric hospital departments in the Netherlands. Study participants were adolescents aged 10 to 18 years. A representative sample of GPs completed questionnaires on the prevalence of CFS in their adolescent patients. Pediatric hospital departments prospectively reported new cases of CFS in adolescent patients. For every new reported case, a questionnaire was sent to the reporting pediatrician and the reported patient to assess CFS morbidity. Prevalence was estimated through the data from GP questionnaires and incidence was estimated on the basis of cases newly reported by pediatricians from January to December 2008. Prevalence was calculated as 111 per 100 000 adolescents and incidence as 12 per 100 000 adolescents per year. Of newly reported patients with CFS, 91% scored at or above cutoff points for severe fatigue and 93% at or above the cutoff points for physical impairment. Forty-five percent of patients with CFS reported >50% school absence during the previous 6 months. Clinically diagnosed incidence and prevalence rates show that adolescent CFS is uncommon compared with chronic fatigue. The primary adverse impact of CFS is extreme disability associated with considerable school absence.

Chronic fatigue syndrome in an ethnically diverse population: the influence of psychosocial adversity and physical inactivity

BackgroundChronic fatigue syndrome (CFS) is a complex multifactorial disorder. This paper reports the prevalence of chronic fatigue (CF) and CFS in an ethnically diverse population sample and tests whether prevalence varies by social adversity, social support, physical inactivity, anxiety and depression.MethodsAnalysis of survey data linking the Health Survey for England (1998 and 1999) and the Ethnic Minority Psychiatric Illness Rates in the Community (EMPIRIC) study undertaken in 2000. The study population comprised a national population sample of 4,281 people ages 16 to 74 years. CF and CFS were operationally defined on the basis of an interview in the EMPIRIC study, alongside questions about psychosocial risk factors. Previous illnesses were reported in the Health Survey for England during 1998 and 1999, as was physical inactivity.ResultsAll ethnic minority groups had a higher prevalence of CFS than the White group. The lowest prevalence was 0.8% in the White group, and it was highest at 3.5% in the Pakistani group (odds ratio (OR), 4.1; 95% confidence interval (95% CI), 1.6 to 10.4). Anxiety (OR, 1.8; 95% CI, 1.4 to 2.2), depression (OR, 1.4; 95% CI, 1.1 to 1.8), physical inactivity (OR, 2.0; 95% CI, 1.1 to 3.8), social strain (OR, 1.24; 95% CI, 1.04 to 1.48) and negative aspects of social support (OR, 2.12; 95% CI, 1.4 to 3.3) were independent risk factors for CFS in the overall sample. Together these risk factors explained ethnic differences in the prevalence of CFS, but no single risk factor could explain a higher prevalence in all ethnic groups.ConclusionsThe prevalence of CFS, but not CF, varies by ethnic group. Anxiety, depression, physical inactivity, social strain and negative aspects of social support together accounted for prevalence differences of CFS in the overall sample.

Characteristics of chronic fatigue syndrome in a Japanese community population

This study seeks to estimate the prevalence of chronic fatigue syndrome (CFS) and assess the characteristics of CFS in a community population in Japan using laboratory tests and questionnaires for lifestyle, fatigue states, and depression states. The design of this study is a cross-sectional observational study. The setting of this study is a medical health checkup program in a general hospital. This study was conducted with 1,430 Japanese (867 men and 563 women), 20 to 78years of age. We classified participants who complained of fatigue according to the case definition of CFS proposed by the Centers for Disease Control and Prevention in the USA in 1994. Alcohol, caffeine, catechin and total polyphenol consumption, smoking status, sleep duration, and physical activity were evaluated using questionnaires. The prevalence of CFS was 1.0% (95% CI 0.5-1.6%) of a community population in Japan. Although various lifestyle factors of the participants with CFS were similar to those without chronic fatigue, average sleep duration was significantly shorter among the participants with CFS (5.5 ± 0.8h) compared to those without chronic fatigue (6.3 ± 0.9h, P < 0.001). Proportion at subjects having average sleep duration of less than 6h was 64.3% among the participants with CFS in contrast to only 15.0% in those without chronic fatigue (P < 0.001). Among the eight case-defining symptoms, "Unrefreshing sleep" had high sensitivity and high specificity for screening CFS in Japanese population (92.9% and 87.8%, respectively). The average sleep duration was notably shorter in Japanese suffering from CFS. Further longitudinal study is needed to evaluate the possibility of extreme short sleep duration as a major cause of CFS in Japan.

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: An Update

Chronic Fatigue Syndrome (CFS), also referred to as Myalgic Encephalomyelitis (ME), is a disease of unknown origin. It is classified as Post Viral Fatigue Syndrome (PVFS) in the WHO International Classification of Diseases (ICD) and listed as sub-category at G93.3 under chapter G93, other disorders of the brain. ME/CFS is primarily an endemic disorder but occurs in both epidemic and sporadic forms. It affects all racial-ethnic groups and is seen in all socioeconomic strata. A diagnosis of CFS is a diagnosis of exclusion, meaning other medical conditions, including psychiatric disorders, must be first ruled out. CFS is diagnosed if there is no other explanation for the fatigue and if the other symptoms did not develop before the fatigue. The estimated worldwide prevalence of CFS is 0.4?1 percent. The disease predominantly affects young adults, with a peak age of onset of between 20 and 40 years, and women, with a female to male ratio of 6:1. Mean illness duration ranges from 3 to 9 years. The patho-physiological mechanism of CFS is unclear but the immunological pattern of CFS patients gleaned from various studies indicates that the immune system is chronically activated. Besides the role of environmental insults (xenobiotics, infectious agents, stress) the genetic features of patients are studied to evaluate their role in triggering the pathology. At present there are no specific pharmacological therapies to treat the disease but a variety of therapeutic approaches have been described as benefiting patients. Treatment programs are directed at relief of symptoms, with the goal of the patient regaining some level of preexisting function and well-being.

Sex Differences in Plasma Prolactin Response to Tryptophan in Chronic Fatigue Syndrome Patients With and Without Comorbid Fibromyalgia

Some think chronic fatigue syndrome (CFS) and fibromyalgia (FM) are variants of the same illness process. This would imply that CFS patients with and without comorbid FM have similar biological underpinnings. To test this, we compared serotonergic-based responses, plasma prolactin (PRL), and self-reported measures of fatigue to intravenous infusion of tryptophan among patients with CFS alone, CFS + FM, and healthy controls. Men and women with CFS alone or CFS + FM and healthy subjects, none with current major depressive disorder (MDD), were given 120 mg of L-tryptophan per kg lean body mass intravenously (i.v.). Before and after tryptophan infusion, blood samples were collected, and plasma PRL, tryptophan, and kynurenine concentrations were determined. Women with CFS alone, but not CFS + FM, showed upregulated plasma PRL responses compared with controls. There were no differences among groups of men. Plasma tryptophan and kynurenine concentrations did not differ among groups. These results indicate that women with CFS alone have upregulated serotonergic tone that is not seen in those with comorbid FM. The lack of effect in men suggests a mechanism that might explain, in part, the increased prevalence of CFS in women. The data support the interpretation that CFS in women is a different illness from FM.

A Constructive Debate With the CDC on the Empirical Case Definition of Chronic Fatigue Syndrome

The Centers for Disease Control and Prevention (CDC) estimates of the prevalence of chronic fatigue syndrome (CFS) have dramatically increased over the past 20 years, from 0.002% to 2.54%. Once considered a rare disorder, CFS is now characterized as a more common chronic health condition, with prevalence numbers suggesting that more than 4 million people in the United States have it. The authors’ research group proposes that selection criteria for CFS cases have broadened and provides data indicating 38% of those with a Major Depressive Disorder were misclassified as having CFS under the new CDC empirical case definition. The authors respond to concerns cited in Reeves, Gurbaxani, Lin, and Unger (2009). Given the importance of standardizing procedures for identifying CFS, more research is needed using different criteria on samples of patients with CFS and other illnesses. The erroneous inclusion of people with primary psychiatric conditions in CFS samples has detrimental consequences for interpreting epidemiologic and etiological findings.

Childhood Maltreatment and Migraine (Part III). Association With Comorbid Pain Conditions

To evaluate in a headache clinic population the relationship of childhood maltreatment on the prevalence of pain conditions comorbid with migraine. Childhood maltreatment is highly prevalent and has been frequently associated with recurrent headache. The relationship of maltreatment and pain has, however, been a subject of some debate. Cross-sectional data on self-reported physician-diagnosed pain conditions were electronically collected from persons with migraine (diagnosed according to International Classification of Headache Disorders-2), seeking treatment in headache clinics at 11 centers across the US and Canada. These included irritable bowel syndrome (IBS), chronic fatigue syndrome (CFS), fibromyalgia (FM), interstitial cystitis (IC), arthritis, endometriosis, and uterine fibroids. Other information included demographics, migraine characteristics (frequency, headache-related disability), remote and current depression (The Patient Health Questionnaire-9), and remote and current anxiety (The Beck Anxiety Inventory). Patients also completed the Childhood Trauma Questionnaire regarding sexual, emotional, and physical abuse, and emotional and physical neglect under the age of 18 years old. Statistical analyses accounted for the survey design and appropriate procedures in SAS such as surveymeans, surveyfreq, and surveylogistic were applied to the weighted data. A total of 1348 migraineurs (88% women) were included in this study (mean age 41 years). Based on physician diagnosis or validated criteria, 31% had IBS, 16% had CFS, and 10% had FM. Diagnosis of IC was reported by 6.5%, arthritis by 25%, and in women, endometriosis was reported by 15% and uterine fibroids by 14%. At least 1 comorbid pain condition was reported by 61%, 2 conditions by 18%, and 3 or more by 13%. Childhood maltreatment was reported by 58% of the patients. Emotional abuse was associated with increased prevalence of IBS, CFS, arthritis, and physical neglect with arthritis. In women, physical abuse was associated with endometriosis and physical neglect with uterine fibroids. Emotional abuse, and physical abuse and neglect (P < .0001 for all) were also associated with increased total number of comorbid conditions. In ordinal logistic regression models, adjusted for sociodemographics and current depression (prevalence 28%) and anxiety (prevalence 56%), emotional abuse (odds ratios [OR] = 1.69, 95% confidence intervals [CI]: 1.224-2.33) and physical neglect (OR = 1.73, 95% CI: 1.22-2.46) were independently associated with an increased number of pain conditions. The cohort of women, similarly, had associations of emotional abuse (OR = 1.94, 95% CI: 1.40-2.72) and physical neglect (OR = 1.90, 95% CI: 1.34-2.68) with an increased number of pain comorbidities. The association of childhood maltreatment and pain was stronger in those reporting multiple pain conditions and multiple maltreatment types. This finding suggests that in migraineurs childhood maltreatment may be a risk factor for development of comorbid pain disorders.