Tag: case-control study

Reproductive correlates of chronic fatigue syndrome

Abstract:

A case-control study was conducted to determine whether menstrual and gynecologic abnormalities precede the onset of chronic fatigue syndrome(CFS) in women with this disorder to a greater extent than that observed among healthy controls.

We identified 150 women who met the 1988 Centers for Disease Control criteria for CFS from the Brigham and Women’s Hospital Cooperative CFS Research Center. A comparison group of 149 women being seen for nongynecologic conditions were selected from the waiting area of the Brigham and Women’s Hospital Internal Medicine outpatient department.

Women with and without CFS completed self-administered questionnaires on menstrual, reproductive, and medical history. Women with CFS reported increased gynecologic complications and a lower incidence of premenstrual symptomatology.

After adjustment for age, a somewhat greater number of cases compared with controls self-reported irregular cycles, periods of amenorrhea, and sporadic bleeding between menstrual periods. Factors suggestive of abnormal ovarian function–such as a history of polycystic ovarian syndrome, hirsutism, and ovarian cysts–were reported more often in CFS cases compared with controls. Frequent anovulatory cycles due to ovarian hyperandrogenism (PCOS) or hyperprolactinemia may increase risk for CFS through loss of the potential immunomodulatory effects of progesterone in the presence of continued estrogen production.

We hypothesize that frequent anovulatory cycles due to PCOS and/or hyperprolactinemia may explain the increased reporting of gynecologic complications and the lower reported premenstrual symptomatology observed in women with CFS.

 

Source: Harlow BL, Signorello LB, Hall JE, Dailey C, Komaroff AL. Reproductive correlates of chronic fatigue syndrome. Am J Med. 1998 Sep 28;105(3A):94S-99S. http://www.ncbi.nlm.nih.gov/pubmed/9790489

 

Post-infection fatigue syndrome following Q fever

Abstract:

In 1989, 147 individuals in the West Midlands, UK, were infected with Q fever. Five years later, following anecdotal reports of fatigue, we used a questionnaire-based case-control study to determine the prevalence of chronic fatigue syndrome symptoms in this group.

Replies from 71 patients were compared with those from 142 age- and sex-matched controls. Increased sweating (52.9% vs. 31.6%, p = 0.006), breathlessness (50.7% vs. 30.6%, p = 0.006), blurred vision (34.3% vs. 17.8%, p = 0.016) and undue tiredness (68.7% vs. 51.5%, p = 0.03) were found in controls compared to cases. These findings were similar to those in Australian abbatoir workers occupationally exposed to Q fever.

CDC criteria for chronic fatigue syndrome were fulfilled by 42.3% of cases and 26% of controls. Using visual analogue scores, symptoms were more severe in cases than in controls. Our findings support the existence of a chronic fatigue state following acute Q fever, in a group of patients exposed just once to the organism, and in circumstances free of such confounding factors as lawsuits over compensation.

 

Source: Ayres JG, Flint N, Smith EG, Tunnicliffe WS, Fletcher TJ, Hammond K, Ward D, Marmion BP. Post-infection fatigue syndrome following Q fever. QJM. 1998 Feb;91(2):105-23. http://qjmed.oxfordjournals.org/content/91/2/105.long

 

Increased illness experience preceding chronic fatigue syndrome: a case control study

Abstract:

BACKGROUND: Almost all published work on chronic fatigue syndrome (CFS) has involved retrospective surveys of cases, which may introduce recall bias. Only medical records collected before diagnosis of CFS can eliminate this.

METHODS: Using data collected several years prior to the development of the illness, we performed a case control study, comparing the reported illness records of all people who subsequently made an insurance claim as a result of CFS, with those of future multiple sclerosis (MS) claimants, and those of non-claimant controls (NC).

RESULTS: The study encompassed 133 CFS, 75 MS and 162 NC cases. CFS cases had recorded significantly more illnesses at time of proposal for insurance than the two control groups, and had significantly more claims between proposal and diagnosis of their disorder. Almost all disease categories were reported higher in future CFS sufferers, lethargy having the highest odds ratio after adjustment in a multivariate model.

INTERPRETATION: The results of this paper on CFS patients who claim permanent health insurance do not support a specific viral or immunological explanation for CFS. We conclude that abnormal illness behaviour is of greater importance than previously recognised.

Comment in:

Increased illness experience preceding chronic fatigue syndrome. [J R Coll Physicians Lond. 1998]

Increased illness experience preceding chronic fatigue syndrome. [J R Coll Physicians Lond. 1998]

 

Source: Hall GH, Hamilton WT, Round AP. Increased illness experience preceding chronic fatigue syndrome: a case control study. J R Coll Physicians Lond. 1998 Jan-Feb;32(1):44-8. http://www.ncbi.nlm.nih.gov/pubmed/9507441

A comparison of salivary cortisol in chronic fatigue syndrome, community depression and healthy controls

Abstract:

BACKGROUND: Previous studies reporting cortisol hyposecretion in chronic fatigue syndrome may have been confounded by venepuncture, fasting and hospitalisation.

METHODS: Morning and evening salivary cortisol were obtained on consecutive days in the first 3 days of the menstrual cycle and compared in three samples of women taking no medication and matched for age: 14 patients with chronic fatigue syndrome, 26 community cases of ICD-10 current depressive episodes and 131 healthy community controls.

RESULTS: The mean evening cortisol was significantly lower in the chronic fatigue syndrome patients compared to controls with depression (P = 0.02) and healthy controls (P = 0.005). Chronic fatigue syndrome patients without psychiatric disorder had significantly lower morning salivary cortisols compared to controls (P = 0.009).

CONCLUSION: Chronic fatigue syndrome patients display cortisol hyposecretion in saliva as well as plasma compared to patients with depression and healthy controls.

LIMITATIONS: Small samples of female patients with cortisol estimated at only two time points in the day. Cortisol secretion may be secondary to other neurotransmitter abnormalities or other physiological or lifestyle factors in chronic fatigue syndrome patients.

CLINICAL RELEVANCE: Chronic fatigue syndrome is biochemically distinct from community depression.

 

Source: Strickland P, Morriss R, Wearden A, Deakin B. A comparison of salivary cortisol in chronic fatigue syndrome, community depression and healthy controls. J Affect Disord. 1998 Jan;47(1-3):191-4. http://www.ncbi.nlm.nih.gov/pubmed/9476760

 

Urinary free cortisol excretion in chronic fatigue syndrome, major depression and in healthy volunteers

Abstract:

Urinary free cortisol excretion (UFC) was compared in 21 patients with chronic fatigue syndrome (CFS), in 10 melancholic depressives and in 15 healthy controls.

Patients with depression had UFC values which were significantly higher than healthy comparison subjects, whereas UFC excretion of CFS patients was significantly lower than the comparison group.

These findings are in keeping with currently held hypotheses of hyperactivity and hypoactivity of the hypothalamic-pituitary-adrenal (HPA) axis in depression and chronic fatigue syndrome respectively. Five of the 21 CFS patients had a co-morbid depressive illness. This sub-group retained the profile of UFC excretion of those with CFS alone, suggesting a different pathophysiological basis for depressive symptoms in CFS.

 

Source: Scott LV, Dinan TG. Urinary free cortisol excretion in chronic fatigue syndrome, major depression and in healthy volunteers. J Affect Disord. 1998 Jan;47(1-3):49-54. http://www.ncbi.nlm.nih.gov/pubmed/9476743

 

Comparison of heart rate variability in patients with chronic fatigue syndrome and controls

Abstract:

Recent studies have reported a close association between chronic fatigue syndrome and neurally mediated hypotension. We hypothesized that this association may result from an abnormality in autonomic function among patients with chronic fatigue syndrome, which may be detectable using an analysis of heart rate variability.

We prospectively studied 19 patients who fulfilled the Centers for Disease Control criteria for chronic fatigue syndrome and 11 controls. Each subject underwent a two-stage tilt-table test while wearing a Holter monitor. Heart rate variability was assessed in the supine baseline position and during upright tilt using frequency domain parameters.

In the baseline supine position, high frequency (HF) power, low frequency (LF) power, and the ratio of low frequency power to high frequency power (LF/HF ratio) were similar. In both patient groups, upright tilt resulted in a similar decrease in HF power, increase in LF power, and increase in the LH/HF ratio.

In conclusion, autonomic function, as assessed using an analysis of heart rate variability, does not differ in the baseline supine state, nor in response to upright tilt among patients with chronic fatigue syndrome and healthy controls.

 

Source: Yataco A, Talo H, Rowe P, Kass DA, Berger RD, Calkins H. Comparison of heart rate variability in patients with chronic fatigue syndrome and controls. Clin Auton Res. 1997 Dec;7(6):293-7. http://www.ncbi.nlm.nih.gov/pubmed/9430800

 

Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA

Abstract:

OBJECTIVES: A prominent feature of chronic fatigue syndrome (CFS) is a disordered immune system. Recent evidence indicates that induction of apoptosis might be mediated in a dysregulated immune system by the upregulation of growth inhibitory cytokines. Therefore, the purpose of this study was to evaluate the apoptotic cell population, interferon-alpha (IFN-alpha) and the IFN-induced protein kinase RNA (PKR) gene transcripts in peripheral blood lymphocytes (PBL) of CFS individuals, as compared to healthy controls.

SUBJECTS AND METHODS: PBL were isolated from CFS (n = 29) and healthy control individuals (n = 15) and subjected to quantitative analysis of apoptotic cell population and cell cycle progression by flow cytometry. Quantitative competitive polymerase chain reaction (Q/C PCR) and Western blot analysis were used to assess the levels of PKR mRNA and protein in control and CFS individuals. In addition, circulating IFN-alpha was measured by ELISA assay.

RESULTS: Increased apoptotic cell population was observed in CFS individuals, as compared to healthy controls (26.6 +/- 12.9% and 9.9 +/- 4.2%, respectively). The increased apoptotic subpopulation in CFS individuals was accompanied by an abnormal cell arrest in the S phase and the G2/M boundary of the cell cycle as compared to the control group (8.6 +/- 1.2 to 22.8 +/- 2.4 and 3.6 +/- 0.82 to 24.3 +/- 3.4, respectively). In addition, CFS individuals exhibited enhanced PKR mRNA and protein levels (mean basal level 3538 +/- 1050 and 2.7 +/- 0.26, respectively) as compared to healthy controls (mean basal level 562 +/- 162 and 0.89 +/- 0.18, respectively). In 50% of the CFS samples (n = 29) treated with 2-aminopurine (2-AP) (a potent inhibitor of PKR) the apoptotic population was reduced by more then 50%.

CONCLUSIONS: PKR-mediated apoptosis in CFS individuals may contribute to the pathogenesis and the fatigue symptomatology associated with CFS.

Comment in: Cortisol deficiency may account for elevated apoptotic cell population in patients with chronic fatigue syndrome. [J Intern Med. 1999]

 

Source: Vojdani A, Ghoneum M, Choppa PC, Magtoto L, Lapp CW. Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA. J Intern Med. 1997 Dec;242(6):465-78. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.1997.tb00019.x/epdf (Full article)

 

Post-Lyme syndrome and chronic fatigue syndrome. Neuropsychiatric similarities and differences

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) and post-Lyme syndrome (PLS) share many features, including symptoms of severe fatigue and cognitive difficulty.

OBJECTIVE: To examine the neuropsychiatric differences in these disorders to enhance understanding of how mood, fatigue, and cognitive performance interrelate in chronic illness.

METHODS: Twenty-five patients with CFS, 38 patients with PLS, and 56 healthy controls participated in the study. Patients with CFS met 1994 criteria for CFS and lacked histories suggestive of Lyme disease. Patients with PLS were seropositive for Lyme disease, had met the Centers for Disease Control and Prevention criteria, or had histories strongly suggestive of Lyme disease and were experiencing severe fatigue that continued 6 months or more following completion of antibiotic treatment for Lyme disease. All subjects completed self-report measures of somatic symptoms and mood disturbance and underwent neuropsychological testing. All patients also underwent a structured psychiatric interview.

RESULTS: Patients with CFS and PLS were similar in several somatic symptoms and in psychiatric profile. Patients with CFS reported more flulike symptoms than patients with PLS. Patients with PLS but not patients with CFS performed significantly worse than controls on tests of attention, verbal memory, verbal fluency, and motor speed. Patients with PLS without a premorbid history of psychiatric illness did relatively worse on cognitive tests than patients with PLS with premorbid psychiatric illness compared with healthy controls.

CONCLUSIONS: Despite symptom overlap, patients with PLS show greater cognitive deficits than patients with CFS compared with healthy controls. This is particularly apparent among patients with PLS who lack premorbid psychiatric illness.

 

Source: Gaudino EA, Coyle PK, Krupp LB. Post-Lyme syndrome and chronic fatigue syndrome. Neuropsychiatric similarities and differences. Arch Neurol. 1997 Nov;54(11):1372-6. http://www.ncbi.nlm.nih.gov/pubmed/9362985

 

Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome

Abstract:

The relationship between orthostatic hypotension and chronic fatigue syndrome (CFS) has been reported previously. To study the pathogenesis and management of delayed orthostatic hypotension in patients with CFS, a case comparison study with follow-up of 8 weeks has been designed.

A group of 78 patients with CFS (mean age 40 years; 49% men and 51% women), who fulfilled the Centre for Disease Control and Prevention criteria were studied. There were 38 healthy controls (mean age 43 years; 47% men and 53% women).

At entry to the study each subject underwent an upright tilt-table test, and clinical and laboratory evaluation. Patients with orthostatic hypotension were offered therapy with sodium chloride (1200 mg) in a sustained-release formulation for 3 weeks, prior to resubmission to the tilt-table testing, and clinical and laboratory evaluation.

An abnormal response to upright tilt was observed in 22 of 78 patients with CFS. After sodium chloride therapy for 8 weeks, tilt-table testing was repeated on the 22 patients with an abnormal response at baseline. Of these 22 patients, 10 redeveloped orthostatic hypotension, while 11 did not show an abnormal response to the test and reported an improvement of CFS symptoms.

However, those CFS patients who again developed an abnormal response to tilt-test had a significantly reduced plasma renin activity (0.79 pmol/ml per h) compared both with healthy controls (1.29 pmol/ml per h) and with those 11 chronic fatigue patients (1.0 pmol/ml per h) who improved after sodium chloride therapy (p = 0.04).

In conclusion, in our study CFS patients who did not respond to sodium chloride therapy were found to have low plasma renin activity. In these patients an abnormal renin-angiotensin-aldosterone system could explain the pathogenesis of orthostatic hypotension and the abnormal response to treatment.

 

Source: De Lorenzo F, Hargreaves J, Kakkar VV. Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome. Clin Auton Res. 1997 Aug;7(4):185-90. http://www.ncbi.nlm.nih.gov/pubmed/9292244

 

The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression

Abstract:

The effects of fatigue on neuropsychological performance were examined in patients with fatiguing illnesses. Repeated testing with the Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977) was employed over the course of a demanding neuropsychological testing session. It was hypothesized that if fatigue affects performance, one would expect to observe “blunting” of the PASAT practice effect.

Fifteen of the study participants live with chronic fatigue syndrome (CFS), 15 with multiple sclerosis (MS), 14 with depression (DEP), and 15 are healthy, sedentary controls. Overall PASAT performance was significantly reduced for CFS and DEP participants compared to controls, whereas mean performance did not differ across the three fatiguing illness groups. Degree of improvement across trials (i.e., practice effect) for the groups did not differ from controls’. Neither subjective fatigue or DEP were significantly related to PASAT performance.

These findings suggest that fatigue does not universally impair performance during neuropsychological assessment even in groups in which fatigue is a prominent symptom.

 

Source: Johnson SK, Lange G, DeLuca J, Korn LR, Natelson B. The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression. Appl Neuropsychol. 1997;4(3):145-53. http://www.ncbi.nlm.nih.gov/pubmed/16318477