Tag: Reeves

Early adverse experience and risk for chronic fatigue syndrome: results from a population-based study

Abstract:

CONTEXT: Chronic fatigue syndrome (CFS) is an important public health problem. The causes of CFS are unknown and effective prevention strategies remain elusive. A growing literature suggests that early adverse experience increases the risk for a range of negative health outcomes, including fatiguing illnesses. Identification of developmental risk factors for CFS is critical to inform pathophysiological research and devise targets for primary prevention.

OBJECTIVE: To examine the relationship between early adverse experience and risk for CFS in a population-based sample of clinically confirmed CFS cases and nonfatigued control subjects.

DESIGN, SETTING, AND PARTICIPANTS: A case-control study of 43 cases with current CFS and 60 nonfatigued controls identified from a general population sample of 56 146 adult residents from Wichita, Kan.

MAIN OUTCOME MEASURES: Self-reported childhood trauma (sexual, physical, and emotional abuse and emotional and physical neglect) and psychopathology (depression, anxiety, and posttraumatic stress disorder) by CFS status.

RESULTS: The CFS cases reported significantly higher levels of childhood trauma and psychopathology compared with the controls. Exposure to childhood trauma was associated with a 3- to 8-fold increased risk for CFS across different trauma types. There was a graded relationship between the degree of trauma exposure and CFS risk. Childhood trauma was associated with greater CFS symptom severity and with symptoms of depression, anxiety, and posttraumatic stress disorder. The risk for CFS conveyed by childhood trauma increased with the presence of concurrent psychopathology.

CONCLUSIONS: This study provides evidence of increased levels of multiple types of childhood trauma in a population-based sample of clinically confirmed CFS cases compared with nonfatigued controls. Our results suggest that childhood trauma is an important risk factor for CFS. This risk was in part associated with altered emotional state. Studies scrutinizing the psychological and neurobiological mechanisms that translate childhood adversity into CFS risk may provide direct targets for the early prevention of CFS.

 

Source: Heim C, Wagner D, Maloney E, Papanicolaou DA, Solomon L, Jones JF, Unger ER, Reeves WC. Early adverse experience and risk for chronic fatigue syndrome: results from a population-based study. Arch Gen Psychiatry. 2006 Nov;63(11):1258-66. https://www.ncbi.nlm.nih.gov/pubmed/17088506

 

Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: prospective cohort study

Abstract:

OBJECTIVE: To delineate the risk factors, symptom patterns, and longitudinal course of prolonged illnesses after a variety of acute infections.

DESIGN: Prospective cohort study following patients from the time of acute infection with Epstein-Barr virus (glandular fever), Coxiella burnetii (Q fever), or Ross River virus (epidemic polyarthritis).

SETTING: The region surrounding the township of Dubbo in rural Australia, encompassing a 200 km geographical radius and 104,400 residents.

PARTICIPANTS: 253 patients enrolled and followed at regular intervals over 12 months by self report, structured interview, and clinical assessment.

OUTCOME MEASURES: Detailed medical, psychiatric, and laboratory evaluations at six months to apply diagnostic criteria for chronic fatigue syndrome. Premorbid and intercurrent illness characteristics recorded to define risk factors for chronic fatigue syndrome. Self reported illness phenotypes compared between infective groups.

RESULTS: Prolonged illness characterised by disabling fatigue, musculoskeletal pain, neurocognitive difficulties, and mood disturbance was evident in 29 (12%) of 253 participants at six months, of whom 28 (11%) met the diagnostic criteria for chronic fatigue syndrome. This post-infective fatigue syndrome phenotype was stereotyped and occurred at a similar incidence after each infection. The syndrome was predicted largely by the severity of the acute illness rather than by demographic, psychological, or microbiological factors.

CONCLUSIONS: A relatively uniform post-infective fatigue syndrome persists in a significant minority of patients for six months or more after clinical infection with several different viral and non-viral micro-organisms. Post-infective fatigue syndrome is a valid illness model for investigating one pathophysiological pathway to chronic fatigue syndrome.

 

Source: Hickie I, Davenport T, Wakefield D, Vollmer-Conna U, Cameron B, Vernon SD, Reeves WC, Lloyd A; Dubbo Infection Outcomes Study Group. Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: prospective cohort study. BMJ. 2006 Sep 16;333(7568):575. Epub 2006 Sep 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1569956/ (Full article)

 

Glucocorticoid receptor polymorphisms and haplotypes associated with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a significant public health problem of unknown etiology, the pathophysiology has not been elucidated, and there are no characteristic physical signs or laboratory abnormalities. Some studies have indicated an association of CFS with deregulation of immune functions and hypothalamic-pituitary-adrenal (HPA) axis activity.

In this study, we examined the association of sequence variations in the glucocorticoid receptor gene (NR3C1) with CFS because NR3C1 is a major effector of the HPA axis. There were 137 study participants (40 with CFS, 55 with insufficient symptoms or fatigue, termed as ISF, and 42 non-fatigued controls) who were clinically evaluated and identified from the general population of Wichita, KS. Nine single nucleotide polymorphisms (SNPs) in NR3C1 were tested for association of polymorphisms and haplotypes with CFS.

We observed an association of multiple SNPs with chronic fatigue compared to non-fatigued (NF) subjects (P < 0.05) and found similar associations with quantitative assessments of functional impairment (by the SF-36), with fatigue (by the Multidimensional Fatigue Inventory) and with symptoms (assessed by the Centers for Disease Control Symptom Inventory).

Subjects homozygous for the major allele of all associated SNPs were at increased risk for CFS with odds ratios ranging from 2.61 (CI 1.05-6.45) to 3.00 (CI 1.12-8.05). Five SNPs, covering a region of approximately 80 kb, demonstrated high linkage disequilibrium (LD) in CFS, but LD gradually declined in ISF to NF subjects. Furthermore, haplotype analysis of the region in LD identified two associated haplotypes with opposite alleles: one protective and the other conferring risk of CFS.

These results demonstrate NR3C1 as a potential mediator of chronic fatigue, and implicate variations in the 5′ region of NR3C1 as a possible mechanism through which the alterations in HPA axis regulation and behavioural characteristics of CFS may manifest.

 

Source: Rajeevan MS, Smith AK, Dimulescu I, Unger ER, Vernon SD, Heim C, Reeves WC. Glucocorticoid receptor polymorphisms and haplotypes associated with chronic fatigue syndrome. Genes Brain Behav. 2007 Mar;6(2):167-76. http://onlinelibrary.wiley.com/doi/10.1111/j.1601-183X.2006.00244.x/full (Full article)

 

Coping styles in people with chronic fatigue syndrome identified from the general population of Wichita, KS

Abstract:

OBJECTIVE: Studies of primary and tertiary care patients suggest that maladaptive coping styles contribute to the pathogenesis and maintenance of chronic fatigue syndrome (CFS). We assessed coping styles in persons with unexplained fatigue and nonfatigued controls in a population-based study.

METHODS: We enrolled 43 subjects meeting the 1994 Research Case Definition of CFS, matching them with 61 subjects with chronic unexplained fatigue who did not meet criteria for CFS [we term them insufficient symptoms or fatigue (ISF)] and 60 non-ill (NI) controls. Coping styles and clinical features of CFS were assessed using standard rating scales.

RESULTS: Subjects with CFS and ISF reported significantly more escape-avoiding behavior than NI controls. There were no differences between the CFS and ISF subjects. Among participants with CFS, escape-avoiding behavior was associated with fatigue severity, pain, and disability.

CONCLUSIONS: We demonstrate significantly higher reporting of maladaptive coping in a population-based sample of people with CFS and other unexplained fatiguing illnesses defined by reproducible standardized clinical empirical means in comparison to NI controls.

 

Source: Nater UM, Wagner D, Solomon L, Jones JF, Unger ER, Papanicolaou DA, Reeves WC, Heim C. Coping styles in people with chronic fatigue syndrome identified from the general population of Wichita, KS. J Psychosom Res. 2006 Jun;60(6):567-73. https://www.ncbi.nlm.nih.gov/pubmed/16731231

 

The challenge of integrating disparate high-content data: epidemiological, clinical and laboratory data collected during an in-hospital study of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating illness characterized by multiple unexplained symptoms including fatigue, cognitive impairment and pain. People with CFS have no characteristic physical signs or diagnostic laboratory abnormalities, and the etiology and pathophysiology remain unknown. CFS represents a complex illness that includes alterations in homeostatic systems, involves multiple body systems and results from the combined action of many genes, environmental factors and risk-conferring behavior. In order to achieve understanding of complex illnesses, such as CFS, studies must collect relevant epidemiological, clinical and laboratory data and then integrate, analyze and interpret the information so as to obtain meaningful clinical and biological insight. This issue of Pharmacogenomics represents such an approach to CFS.

Data was collected during a 2-day in-hospital study of persons with CFS, other medically and psychiatrically unexplained fatiguing illnesses and nonfatigued controls identified from the general population of Wichita, KS, USA. While in the hospital, the participants’ psychiatric status, sleep characteristics and cognitive functioning was evaluated, and biological samples were collected to measure neuroendocrine status, autonomic nervous system function, systemic cytokines and peripheral blood gene expression. The data generated from these assessments was made available to a multidisciplinary group of 20 investigators from around the world who were challenged with revealing new insight and algorithms for integration of this complex, high-content data and, if possible, identifying molecular markers and elucidating pathophysiology of chronic fatigue. The group was divided into four teams with representation from the disciplines of medicine, mathematics, biology, engineering and computer science. The papers in this issue are the culmination of this 6-month challenge, and demonstrate that data integration and multidisciplinary collaboration can indeed yield novel approaches for handling large, complex datasets, and reveal new insight and relevance to a complex illness such as CFS.

Comment in: The postgenomic era and complex disease. [Pharmacogenomics. 2006]

 

Source: Vernon SD, Reeves WC. The challenge of integrating disparate high-content data: epidemiological, clinical and laboratory data collected during an in-hospital study of chronic fatigue syndrome. Pharmacogenomics. 2006 Apr;7(3):345-54. https://www.ncbi.nlm.nih.gov/pubmed/16610945

 

Challenges for molecular profiling of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is prevalent, disabling and costly. Despite extensive literature describing the epidemiology and clinical aspects of CFS, it has been recalcitrant to diagnostic biomarker discovery and therapeutic intervention. This is due to the fact that CFS is a complex illness defined by self-reported symptoms and diagnosed by the exclusion of medical and psychiatric diseases that may explain the symptoms.

Studies attempting to dissect the pathophysiology are challenging to design as CFS affects multiple body systems, making the choice of which system to study dependent on an investigators area of expertise. However, the peripheral blood appears to be facilitating the molecular profiling of several diseases, such as CFS, that involve bodywide perturbations that are mediated by the CNS. Successful molecular profiling of CFS will require the integration of genetic, genomic and proteomic data with environmental and behavioral data to define the heterogeneity in order to optimize intervention.

 

Source: Vernon SD, Whistler T, Aslakson E, Rajeevan M, Reeves WC. Challenges for molecular profiling of chronic fatigue syndrome. Pharmacogenomics. 2006 Mar;7(2):211-8. https://www.ncbi.nlm.nih.gov/pubmed/16515400

 

Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome

Abstract:

Patients with chronic fatigue syndrome (CFS) frequently complain of cognitive dysfunction. However, evidence of cognitive impairment in CFS patients has been found in some, but not other, studies. This heterogeneity in findings may stem from the relative presence of mental fatigue in the patient populations examined. The present study assessed this possibility in a population-based sample of CFS patients.

In all, 43 patients with CFS defined by the criteria of the 1994 research case definition using measurements recommended by the 2003 International CFS Study Group, and 53 age-, sex-, and race/ethnicity-matched nonfatigued subjects were included in the study. Mental fatigue was assessed using the mental fatigue subscale of the multidimensional fatigue inventory. Cognitive function was evaluated using an automated battery of computerized tests (Cambridge neuropsychological test automated battery (CANTAB)) that assessed psychomotor function, planning and problem-solving abilities, and memory and attentional performance.

CFS patients with significant complaints of mental fatigue (score of mental fatigue 2 standard deviations above the mean of nonfatigued subjects) exhibited significant impairment in the spatial working memory and sustained attention (rapid visual information processing) tasks when compared to CFS patients with low complaints of mental fatigue and nonfatigued subjects. In CFS patients with significant mental fatigue, sustained attention performance was impaired only in the final stages of the test, indicating greater cognitive fatigability in these patients. CFS patients with low mental fatigue displayed performance comparable to nonfatigued subjects on all tests of the CANTAB battery. These findings show strong concordance between subjective complaints of mental fatigue and objective measurement of cognitive impairment in CFS patients and suggest that mental fatigue is an important component of CFS-related cognitive dysfunction.

 

Source: Capuron L, Welberg L, Heim C, Wagner D, Solomon L, Papanicolaou DA, Craddock RC, Miller AH, Reeves WC. Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome. Neuropsychopharmacology. 2006 Aug;31(8):1777-84. Epub 2006 Jan 4. http://www.nature.com/npp/journal/v31/n8/full/1301005a.html (Full article)

 

Orthostatic instability in a population-based study of chronic fatigue syndrome

Abstract:

PURPOSE: Autonomic nervous system dysfunction has been suggested as involved in the pathophysiology of chronic fatigue syndrome. This population-based case control study addressed the potential association between orthostatic instability (one sign of dysautonomia) and chronic fatigue syndrome.

SUBJECTS AND METHODS: Fifty-eight subjects who fulfilled criteria of the 1994 chronic fatigue syndrome research case definition and 55 healthy controls participated in a 2-day inpatient evaluation. Subjects had been identified during a 4-year population-based chronic fatigue syndrome surveillance study in Wichita, Kan. The present study evaluated subjects’ current medical and psychiatric status, reviewed past medical/psychiatric history and medication use, used a stand-up test to screen for orthostatic instability, and conducted a head-up tilt table test to diagnose orthostatic instability.

RESULTS: No one manifested orthostatic instability in the stand-up test. The head-up tilt test elicited orthostatic instability in 30% of eligible chronic fatigue syndrome subjects (all with postural orthostatic tachycardia) and 48% of controls (50% with neurally mediated hypotension); intolerance was present in only nonfatigued (n=7) subjects. Neither fatigue nor illness severity were associated with outcome.

CONCLUSIONS: Orthostatic instability was similar in persons with chronic fatigue syndrome and nonfatigued controls subjects recruited from the general Wichita population. Delayed responses to head-up tilt tests were common and may reflect hydration status. These findings suggest reappraisal of primary dysautonomia as a factor in the pathogenesis of chronic fatigue syndrome.

Comment in: Orthostatic intolerance in chronic fatigue syndrome. [Am J Med. 2007]

 

Source: Jones JF, Nicholson A, Nisenbaum R, Papanicolaou DA, Solomon L, Boneva R, Heim C, Reeves WC. Orthostatic instability in a population-based study of chronic fatigue syndrome. Am J Med. 2005 Dec;118(12):1415. http://www.ncbi.nlm.nih.gov/pubmed/16378795

 

Chronic fatigue syndrome–a clinically empirical approach to its definition and study

Abstract:

BACKGROUND: The lack of standardized criteria for defining chronic fatigue syndrome (CFS) has constrained research. The objective of this study was to apply the 1994 CFS criteria by standardized reproducible criteria.

METHODS: This population-based case control study enrolled 227 adults identified from the population of Wichita with: (1) CFS (n = 58); (2) non-fatigued controls matched to CFS on sex, race, age and body mass index (n = 55); (3) persons with medically unexplained fatigue not CFS, which we term ISF (n = 59); (4) CFS accompanied by melancholic depression (n = 27); and (5) ISF plus melancholic depression (n = 28). Participants were admitted to a hospital for two days and underwent medical history and physical examination, the Diagnostic Interview Schedule, and laboratory testing to identify medical and psychiatric conditions exclusionary for CFS. Illness classification at the time of the clinical study utilized two algorithms: (1) the same criteria as in the surveillance study; (2) a standardized clinically empirical algorithm based on quantitative assessment of the major domains of CFS (impairment, fatigue, and accompanying symptoms).

RESULTS: One hundred and sixty-four participants had no exclusionary conditions at the time of this study. Clinically empirical classification identified 43 subjects as CFS, 57 as ISF, and 64 as not ill. There was minimal association between the empirical classification and classification by the surveillance criteria. Subjects empirically classified as CFS had significantly worse impairment (evaluated by the SF-36), more severe fatigue (documented by the multidimensional fatigue inventory), more frequent and severe accompanying symptoms than those with ISF, who in turn had significantly worse scores than the not ill; this was not true for classification by the surveillance algorithm.

CONCLUSION: The empirical definition includes all aspects of CFS specified in the 1994 case definition and identifies persons with CFS in a precise manner that can be readily reproduced by both investigators and clinicians.

 

Source: Reeves WC, Wagner D, Nisenbaum R, Jones JF, Gurbaxani B, Solomon L, Papanicolaou DA, Unger ER, Vernon SD, Heim C. Chronic fatigue syndrome–a clinically empirical approach to its definition and study. BMC Med. 2005 Dec 15;3:19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1334212/ (Full article)

 

Psychometric properties of the CDC Symptom Inventory for assessment of chronic fatigue syndrome

Abstract:

OBJECTIVES: Validated or standardized self-report questionnaires used in research studies and clinical evaluation of chronic fatigue syndrome(CFS) generally focus on the assessment of fatigue. There are relatively few published questionnaires that evaluate case defining and other accompanying symptoms in CFS. This paper introduces the self-report CDC CFS Symptom Inventory and analyzes its psychometric properties.

METHODS: One hundred sixty-four subjects (with CFS, other fatiguing illnesses and non fatigued controls) identified from the general population of Wichita, Kansas were enrolled. Evaluation included a physical examination, a standardized psychiatric interview, three previously validated self-report questionnaires measuring fatigue and illness impact (Medical Outcomes Survey Short-Form-36 [MOS SF-36], Multidimensional Fatigue Inventory [MFI], Chalder Fatigue Scale), and the CDC CFS Symptom Inventory. Based on theoretical assumptions and statistical analyses, we developed several different Symptom Inventory scores and evaluated them on their ability to differentiate between participants with CFS and non-fatigued controls.

RESULTS: The Symptom Inventory had good internal consistency and excellent convergent validity. A Total score (all symptoms), Case Definition score (CFS case defining symptoms) and Short Form score (6 symptoms with minimal correlation) differentiated CFS cases from controls. Furthermore, both the Case Definition and Short Form scores distinguished people with CFS from fatigued subjects who did not meet criteria for CFS.

CONCLUSION: The Symptom Inventory appears to be a reliable and valid instrument to assess symptoms that accompany CFS. It is a positive addition to existing instruments measuring fatigue because it allows other dimensions of the illness to be assessed. Further research is needed to confirm and replicate the current findings in a normative population.

 

Source: Wagner D, Nisenbaum R, Heim C, Jones JF, Unger ER, Reeves WC. Psychometric properties of the CDC Symptom Inventory for assessment of chronic fatigue syndrome. Popul Health Metr. 2005 Jul 22;3:8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1183246/ (Full article)