Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndromepatients with and without comorbid fibromyalgia

Abstract:

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.

 

Source: Weaver SA, Janal MN, Aktan N, Ottenweller JE, Natelson BH. Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndrome patients with and without comorbid fibromyalgia. J Womens Health (Larchmt). 2010 May;19(5):951-8. doi: 10.1089/jwh.2009.1697. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2875960/ (Full article)

 

Teaching medical students about medically unexplained illnesses: a preliminary study

Abstract:

BACKGROUND: This study examined how an interactive seminar focusing on two medically unexplained illnesses, chronic fatigue syndrome (CFS) and fibromyalgia, influenced medical student attitudes toward CFS, a more strongly stigmatized illness.

METHODS: Forty-five fourth year medical students attended a 90 minute interactive seminar on the management of medically unexplained illnesses that was exemplified with CFS and fibromyalgia. A modified version of the CFS attitudes test was administered immediately before and after the seminar.

RESULTS: Pre-seminar assessment revealed neutral to slightly favorable toward CFS. At the end of the seminar, significantly more favorable attitudes were found toward CFS in general (t (42) = 2.77; P < 0.01) and for specific items that focused on (1) supporting more CFS research funding (t (42) = 4.32; P < 0.001; (2) employers providing flexible hours for people with CFS (t (42) = 3.52, P < 0.01); and (3) viewing CFS as not primarily a psychological disorder (t (42) = 2.87, P < 0.01). Thus, a relatively brief exposure to factual information on specific medically unexplained illnesses was associated with more favorable attitudes toward CFS in fourth year medical students.

CONCLUSION: This type of instruction may lead to potentially more receptive professional attitudes toward providing care to these underserved patients.

 

Source: Friedberg F, Sohl SJ, Halperin PJ. Teaching medical students about medically unexplained illnesses: a preliminary study. Med Teach. 2008;30(6):618-21. doi: 10.1080/01421590801946970. https://www.ncbi.nlm.nih.gov/pubmed/18608944

 

Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia

Abstract:

INTRODUCTION: We evaluated polysomnograms of chronic fatigue syndrome (CFS) patients with and without fibromyalgia to determine whether patients in either group had elevated rates of sleep-disturbed breathing (obstructive sleep apnea or upper airway resistance syndrome) or periodic leg movement disorder. We also determined whether feelings of unrefreshing sleep were associated with differences in sleep architecture from normal.

METHODS: We compared sleep structures and subjective scores on visual analog scales for sleepiness and fatigue in CFS patients with or without coexisting fibromyalgia (n = 12 and 14, respectively) with 26 healthy subjects. None had current major depressive disorder, and all were studied at the same menstrual phase.

RESULTS: CFS patients had significant differences in polysomnograpic findings from healthy controls and felt sleepier and more fatigued than controls after a night’s sleep. CFS patients as a group had less total sleep time, lower sleep efficiency, and less rapid eye movement sleep than controls. A possible explanation for the unrefreshing quality of sleep in CFS patients was revealed by stratification of patients into those who reported more or less sleepiness after a night’s sleep (a.m. sleepier or a.m. less sleepy, respectively). Those in the sleepier group reported that sleep did not improve their symptoms and had poorer sleep efficiencies and shorter runs of sleep than both controls and patients in the less sleepy group; patients in the less sleepy group reported reduced fatigue and pain after sleep and had relatively normal sleep structures. This difference in sleep effects was due primarily to a decrease in the length of periods of uninterrupted sleep in the a.m. sleepier group.

CONCLUSION: CFS patients had significant differences in polysomnographic findings from healthy controls and felt sleepier and more fatigued than controls after a night’s sleep. This difference was due neither to diagnosable sleep disorders nor to coexisting fibromyalgia but primarily to a decrease in the length of periods of uninterrupted sleep in the patients with more sleepiness in the morning than on the night before. This sleep disruption may explain the overwhelming fatigue, report of unrefreshing sleep, and pain in this subgroup of patients.

Comment in: How much sleep apnea is too much? [Arthritis Res Ther. 2009]

 

Source: Togo F, Natelson BH, Cherniack NS, FitzGibbons J, Garcon C, Rapoport DM. Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia. Arthritis Res Ther. 2008;10(3):R56. doi: 10.1186/ar2425. Epub 2008 May 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2483445/ (Full article)

 

Electrocardiographic QT interval and cardiovascular reactivity in fibromyalgia differ from chronic fatigue syndrome

Abstract:

BACKGROUND: Fibromyalgia (FM) and chronic fatigue syndrome (CFS) frequently overlap clinically and have been considered variants of one common disorder. We have recently shown that CFS is associated with a short corrected electrocardiographic QT interval (QTc). In the present study, we evaluated whether FM and CFS can be distinguished by QTc.

METHODS: The study groups were comprised of women with FM (n=30) and with CFS (n=28). The patients were evaluated with a 10 min supine-30 min head-up tilt test. The electrocardiographic QT interval was corrected for heart rate (HR) according to Fridericia’s equation (QTc). In addition, cardiovascular reactivity was assessed based on blood pressure and HR changes and was expressed as the ‘hemodynamic instability score’ (HIS).

RESULTS: The average supine QTc in FM was 417 ms (SD 25) versus 372 ms (SD 22) in CFS (p<0.0001); the supine QTc cut-off <385.7 ms was 79% sensitive and 87% specific for CFS vs. FM. The average QTc at the 10th minute of tilt was 409 ms (SD 18) in FM versus 367 ms (SD 21) in CFS (p<0.0001); the tilt QTc cut-off <383.3 ms was 71% sensitive and 91% specific for CFS vs. FM. The average HIS in FM patients was -3.52 (SD 1.96) versus +3.21 (SD 2.43) in CFS (p<0.0001).

CONCLUSION: A relatively short QTc and positive HIS characterize CFS patients and distinguish them from FM patients. These data may support the contention that FM and CFS are separate disorders.

 

Source: Naschitz JE, Slobodin G, Sharif D, Fields M, Isseroff H, Sabo E, Rosner I. Electrocardiographic QT interval and cardiovascular reactivity in fibromyalgia differ from chronic fatigue syndrome. Eur J Intern Med. 2008 May;19(3):187-91. doi: 10.1016/j.ejim.2007.08.003. Epub 2007 Nov 19. https://www.ncbi.nlm.nih.gov/pubmed/18395162

 

Publication trends in chronic fatigue syndrome: comparisons with fibromyalgia and fatigue: 1995-2004

Abstract:

OBJECTIVE: In order to identify publishing patterns in chronic fatigue syndrome (CFS), we compared the annual number of peer review articles for CFS, fibromyalgia (FM), and non-CFS fatigue over a recent decade (1995-2004).

METHOD: Citations were drawn from Ovid/Medline, PsychInfo, and the Journal of Chronic Fatigue Syndrome for peer review articles focusing on CFS, FM, and fatigue for each year of the decade ending in 2004. Statistics included chi-square, tests for differences in proportions, and regression-based curve estimation.

RESULTS: The frequency of CFS peer review articles did not significantly change from the first half to the second half of the decade (1995-2004). By comparison, the output of both FM and fatigue articles significantly increased (P<.0001). A quadratic model (inverted U shape; P<.02) best fit the data for CFS annual publication frequency. By comparison, exponential models best fit the data for both FM (P<.0001) and fatigue (P<.0001) citations. The highest percentage of citations (15-16%) for both CFS and FM fell within the domains of diagnosis, physiopathology, and psychology. For fatigue, almost one third (31.4%) of the citations were focused on etiology, while psychology (11.5%) and physiopathology (10.4%) articles were the next most cited. Based on first-author affiliation, CFS articles were most likely to originate in the United States (37.7%), England (31.4%), and the Netherlands (4.9%).

CONCLUSION: The output of CFS peer review articles has not increased over the past decade, while the number of FM and fatigue articles has increased substantially.

 

Source: Friedberg F, Sohl S, Schmeizer B. Publication trends in chronic fatigue syndrome: comparisons with fibromyalgia and fatigue: 1995-2004. J Psychosom Res. 2007 Aug;63(2):143-6. https://www.ncbi.nlm.nih.gov/pubmed/17662750

 

Basal circadian and pulsatile ACTH and cortisol secretion in patients with fibromyalgia and/or chronic fatigue syndrome

Abstract:

The objective of this study was to evaluate and compare the basal circadian and pulsatile architecture of the HPA axis in groups of patients with FMS, CFS, or both syndromes with individually matched control groups.

Forty patients with either FMS (n = 13), FMS and CFS (n = 12), or CFS (n = 15) were matched by age (18-65), sex, and menstrual status to healthy controls. Subjects were excluded if they met criteria for major Axis I psychiatric disorders by structured clinical interview (SCID). Subjects were admitted to the General Clinical Research Center where meals and activities were standardized. Blood was collected from an intravenous line every 10 min over 24 h for analysis of ACTH and cortisol. Samples were evaluable for ACTH in 36 subject pairs and for cortisol in 37 subject pairs.

There was a significant delay in the rate of decline from acrophase to nadir for cortisol levels in patients with FMS (P <.01). Elevation of cortisol in the late evening quiescent period was evident in half of the FMS patients compared with their control group, while cortisol levels were numerically, but not significantly, lower in the overnight period in patients with CFS compared with their control group. Pulsatility analyses did not reveal statistically significant differences between patient and control groups.

We conclude that the pattern of differences for basal circadian architecture of HPA axis hormones differs between patients with FMS and CFS compared to their matched control groups. The abnormalities in FMS patients are consistent with loss of HPA axis resiliency.

 

Source: Crofford LJ, Young EA, Engleberg NC, Korszun A, Brucksch CB, McClure LA, Brown MB, Demitrack MA. Basal circadian and pulsatile ACTH and cortisol secretion in patients with fibromyalgia and/or chronic fatigue syndrome. Brain Behav Immun. 2004 Jul;18(4):314-25. http://www.ncbi.nlm.nih.gov/pubmed/15157948