large-scale study – American ME and CFS Society

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Impact on Quality of Life (QoL) of Persons with ME/CFS

Abstract:

Background and Objectives: We previously reported on the impact of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) on the QoL of persons with ME/CFS and their family members. Here, we present the findings of the impact on the QoL of individuals with ME/CFS whose family members did not participate in the survey.

Materials and Methods: A prospective multinational online survey was disseminated via patient charities, support groups and social media. Persons with ME/CFS completed the EuroQoL questionnaire (EQ-5D-3L).

Results: Data were analysed from 876 participants from 26 countries who reported a health care professional diagnosis of ME/CFS. In total, 742 participants identified as female, 124 male and 10 preferred not to say. The mean age of the participants was 47 years (range 18-82), and the mean time to diagnosis was 14 years. The mean overall health status on a visual analogue scale for people with ME/CFS was 36.4 (100 = best health). People with ME/CFS were most often affected by inability to perform usual activities (n = 852, 97%), followed by pain (n = 809, 92%), impaired mobility (n = 724, 83%), difficulty in self-care (n = 561, 64%) and least often affected by anxiety and depression (n = 540, 62%).

Conclusions: The QoL of people with ME/CFS is significantly affected globally. There was no significant difference in quality of life compared with previously published data on those with ME/CFS who did have a family member complete the family member quality of life questionnaire (FROM16). Contrary to popular misconception, anxiety and depression are the least often affected areas in persons with ME/CFS who are most impacted by their inability to perform usual activities.

Source: Muirhead NL, Vyas J, Ephgrave R, Singh R, Finlay AY. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Impact on Quality of Life (QoL) of Persons with ME/CFS. Medicina (Kaunas). 2024 Jul 27;60(8):1215. doi: 10.3390/medicina60081215. PMID: 39202496. https://www.mdpi.com/1648-9144/60/8/1215 (Full text)

Replicated blood-based biomarkers for Myalgic Encephalomyelitis not explicable by inactivity

Abstract:

Myalgic Encephalomyelitis (ME; sometimes referred to as chronic fatigue syndrome) is a relatively common and female-biased disease of unknown pathogenesis that profoundly decreases patients’ health-related quality-of-life. ME diagnosis is hindered by the absence of robustly-defined and specific biomarkers that are easily measured from available sources such as blood, and unaffected by ME patients’ low level of physical activity.

Previous studies of blood biomarkers have not yielded replicated results, perhaps due to low study sample sizes (n<100). Here, we use UK Biobank (UKB) data for up to 1,455 ME cases and 131,303 population controls to discover hundreds of molecular and cellular blood traits that differ significantly between cases and controls. Importantly, 116 of these traits are replicated, as they are significant for both female and male cohorts.

Our analysis used semi-parametric efficient estimators, an initial Super Learner fit followed by a one-step correction, three types of mediators, and natural direct and indirect estimands, to decompose the average effect of ME status on molecular and cellular traits. Strikingly, these trait differences cannot be explained by ME cases’ restricted activity.

Of 3,237 traits considered, ME status had a significant effect on only one, via the “Duration of walk” (UKB field 874) mediator. By contrast, ME status had a significant direct effect on 290 traits (9%). As expected, these effects became more significant with increased stringency of case and control definition.

Significant female and male traits were indicative of chronic inflammation, insulin resistance and liver disease. Individually, significant effects on blood traits, however, were not sufficient to cleanly distinguish cases from controls. Nevertheless, their large number, lack of sex-bias, and strong significance, despite the ‘healthy volunteer’ selection bias of UKB participants, keep alive the future ambition of a blood-based biomarker panel for accurate ME diagnosis.

Source: Sjoerd V Beentjes, Julia Kaczmarczyk, Amanda Cassar, Gemma Louise Samms, Nima S Hejazi, Ava Khamseh, Chris P Ponting. Replicated blood-based biomarkers for Myalgic Encephalomyelitis not explicable by inactivity. medRxiv 2024.08.26.24312606; doi: https://doi.org/10.1101/2024.08.26.24312606 https://www.medrxiv.org/content/10.1101/2024.08.26.24312606v1 (Full text available as PDF file)

The risks of autoimmune- and inflammatory post-acute COVID-19 conditions: a network cohort study in six European countries, the US, and Korea

ABSTRACT

Objectives We aimed to assess the risk of autoimmune- and inflammatory post-acute COVID-19 conditions.

Design Descriptive network cohort study.

Setting Electronic health records from UK and Dutch primary care, Norwegian linked health registry, hospital records of specialist centres in Spain, France, and Korea, and healthcare claims from Estonia and the US.

Participants We followed individuals between September 2020 and the latest available data from the day they fulfilled at least 365 days of prior observation (general population), additionally from day 91 after a SARS-Cov-2 negative test (comparator) or a COVID-19 record (exposed patients).

Main outcome measures We assessed postural orthostatic tachycardia syndrome (POTS) diagnoses/symptoms, myalgic encephalomyelitis / chronic fatigues syndrome (ME/CFS) diagnoses/symptoms, multi-inflammatory syndrome (MIS), and several autoimmune diseases. For contextualisation, we assessed any diabetes mellitus (DM).

Meta-analysed crude incidence rate ratios (IRR) of outcomes measures after COVID-19 versus negative testing yield the ratios of absolute risks. Furthermore, incidence rates (IR) of the outcomes in the general population describe the total disease burden.

Results We included 34’549’575 individuals of whom 2’521’812 had COVID-19, and 4’233’145 a first negative test. After COVID-19 compared to test negative patients, we observed IRRs of 1.24 (1.23-1.25), 1.22 (1.21-1.23), and 1.12 (1.04-1.21) for POTS symptoms, ME/CFS symptoms and diagnoses, respectively. In contrast, autoimmune diseases and DM did not yield higher rates after COVID-19. In individual general database populations, IRs of POTS and ME/CFS diagnoses were 17-1’477/100’000 person-years (pys) and 2-473/100’000 pys, respectively. IRs of MIS were lowest with IRs 0.4-16/100’000 pys, those of DM as a benchmark 8-86/100’000 pys. IRs largely depended on the care setting.

Conclusion In our unmatched comparison, we observed that, following COVID-19, POTS and ME/CFS yielded higher rates than after negative testing. In absolute terms, we observed POTS and ME/CFS diagnoses to have a similar disease burden as DM.

WHAT IS ALREADY KNOWN ON THIS TOPIC

Observational research suggested positive associations between COVID-19 and so called post-acute COVID-19 conditions, whose spectrum is yet to be established
Basic research suggested pathways that link COVID-19 with autoimmune- and inflammatory diseases such as postural orthostatic tachycardia syndrome (POTS), myalgic encephalomyelitis / chronic fatigues syndrome (ME/CFS), multiple inflammatory syndrome (MIS), and autoimmune diseases

WHAT THIS STUDY ADDS

After COVID-19, the rates of POTS symptoms and ME/CFS symptoms/diagnoses was higher than those after negative testing
After COVID-19 versus negative testing, rates of ME/CFS diagnoses were increased in the working age group and rates of symptoms of POTS and ME/CFS were increased in children and elderly
Disease burdens of POTS and ME/CFS diagnoses in the general population were higher among women than among men and overall similar to that of diabetes mellitus

Source: Theresa Burkard, Kim López-Güell, Martí Català, Edward Burn, Antonella Delmestri, Sara Khalid, Annika M Joedicke, Daniel Dedman, Jessie O Oyinlola, Alicia Abellan, Laura Pérez-Crespo, Núria Mercadé-Besora, Talita Duarte-Salles, Daniel Prieto-Alhambra, Johnmary T Arinze, Mees Mosseveld, Raivo Kolde, Jaime Meléndez-Cardiel, Raúl López-Blasco, Álvaro Martínez, Bernardo Valdivieso, Dominique Delseny, Gregoire Mercier, Chungsoo Kim, Ji-woo Kim, Kristin Kostka, Juan Manuel Ramírez-Anguita, Miguel A Mayer, Nhung TH Trinh, Hedvig ME Nordeng, Roger Paredes, Anneli Uusküla, Akihiko Nishimura, Cora Loste, Lourdes Mateu, Junqing Xie. The risks of autoimmune- and inflammatory post-acute COVID-19 conditions: a network cohort study in six European countries, the US, and Korea. medRxiv 2024.05.15.24307344; doi: https://doi.org/10.1101/2024.05.15.24307344 https://www.medrxiv.org/content/10.1101/2024.05.15.24307344v1.full-text (Full text)

Long-term neurologic outcomes of COVID-19

Abstract:

The neurologic manifestations of acute COVID-19 are well characterized, but a comprehensive evaluation of postacute neurologic sequelae at 1 year has not been undertaken. Here we use the national healthcare databases of the US Department of Veterans Affairs to build a cohort of 154,068 individuals with COVID-19, 5,638,795 contemporary controls and 5,859,621 historical controls; we use inverse probability weighting to balance the cohorts, and estimate risks and burdens of incident neurologic disorders at 12 months following acute SARS-CoV-2 infection.

Our results show that in the postacute phase of COVID-19, there was increased risk of an array of incident neurologic sequelae including ischemic and hemorrhagic stroke, cognition and memory disorders, peripheral nervous system disorders, episodic disorders (for example, migraine and seizures), extrapyramidal and movement disorders, mental health disorders, musculoskeletal disorders, sensory disorders, Guillain–Barré syndrome, and encephalitis or encephalopathy.

We estimated that the hazard ratio of any neurologic sequela was 1.42 (95% confidence intervals 1.38, 1.47) and burden 70.69 (95% confidence intervals 63.54, 78.01) per 1,000 persons at 12 months. The risks and burdens were elevated even in people who did not require hospitalization during acute COVID-19. Limitations include a cohort comprising mostly White males. Taken together, our results provide evidence of increased risk of long-term neurologic disorders in people who had COVID-19.

Source: Xu, E., Xie, Y. & Al-Aly, Z. Long-term neurologic outcomes of COVID-19. Nat Med (2022). https://doi.org/10.1038/s41591-022-02001-z https://www.nature.com/articles/s41591-022-02001-z (Full text)

Immunogenetic studies in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease that affects about 0.1-0.2% of the general population. The core symptoms are persistent debilitating fatigue, post-exertional malaise (PEM) and cognitive dysfunction. Most symptoms of ME/CFS are not disease specific. Additionally, there is a lack of both biomarkers and diagnostic tests for the disease, which makes accurate diagnosis difficult.

More than 20 different patient classifications and diagnostic criteria have emerged over the last four decades. Due to this, the patient population can be quite heterogeneous in terms of clinical symptoms and the extent to which the disease impacts quality of life.

There are several different theories that aim to explain the disease development of ME/CFS. In this thesis, we have taken as our starting point the growing evidence for an immunological background for ME/CFS pathogenesis. Several studies have pointed to altered NK cells, autoantibodies and T cell abnormalities in ME/CFS patients.

In addition, several genetic studies reported significant associations in various immunologically relevant genes. Most of these previous studies have been suboptimal and included heterogeneous patient populations and/or few patients in total.

Therefore, we aimed to gain a better understanding of the role of immunologically relevant genes and disease development of ME/CFS.

To do this, we employed known strategies from genetic studies in autoimmune disease and applied them to ME/CFS. We used strict quality control and included, to the best of our knowledge, the largest cohort diagnosed with the Canadian consensus criteria.

In paper I, the main goal was to follow up previously performed work by our group that reported associations between ME/CFS and HLA-C: 07: 04 and HLA-DQB1: 03: 03 alleles. The HLA (human leukocyte antigen) region consists a multitude of immunologically relevant genes in addition to the HLA genes, and there is extensive and complex linkage disequilibrium (LD) in the region.

The previously observed association signals in the HLA region were fine-mapped by genotyping five additional classical HLA loci and 5,342 SNPs (single nucleotide variants) in 427 Norwegian ME/CFS patients, diagnosed according to the Canadian consensus criteria, and 480 healthy Norwegian controls. The analysis revealed two independent association signals (p ≤ 0.001) represented by the genetic variants rs4711249 in the HLA class I region and rs9275582 in the HLA class II region.

The primary association signal in the HLA class II region was located in the vicinity of the HLA-DQ genetic region, most likely due to the HLA-DQB1 gene. In particular, amino acid position 57 (aspartic acid / alanine) in the peptide binding pit of HLA-DQB1, or an SNP upstream of HLA-DQB1 seemed to explain the association signal we observed in the HLA class II region.

In the HLA class I region, the putative primary locus was not as clear and could possibly lie outside the classical HLA genes (the association signal spans several genes DDR1, GTF2H4, VARS2, SFTA2 and DPCR1) with expression levels influenced by the ME/CFS associated SNP genotypes.

Interestingly, we also observed that > 60% of the patients who responded to cyclophosphamide treatment for ME/CFS had either the rs4711249 risk allele and/or DQB1* 03:03 versus 12% of the patients who did not respond to the treatment. Our findings suggest the involvement of the HLA region, and in particular the HLA-DQB1 gene, in ME/CFS.

Although our study is the largest to date, it is still a relatively small study in the context of genetic studies. Our findings need to be replicated in much larger, statistically more representative, cohorts.

In particular, it is necessary to investigate the involvement of HLA- 12 DQB1, a gene that contains alleles that increase the risk of several established autoimmune diseases such as celiac disease.

In paper II, we aimed to investigate immunologically relevant genes using a genotyping array (iChip) targeting immunological gene regions previously associated with different autoimmune diseases.

In addition to the Norwegian cohort of 427 ME/CFS patients (the Canadian consensus criteria), we also analyzed data from two replication cohorts, a Danish one of 460 ME/CFS patients (Canadian consensus criteria) and a data set from the UK Biobank of 2105 self-reported CFS patients.

To the best of our knowledge, this is the first ME/CFS genetic association study of this magnitude and it included more than 2,900 patients in total (of whom 887 are diagnosed according to Canadian consensus criteria).

We found no ME/CFS risk variants with a genome wide significance level (p<5×10-8), but we identified six gene regions (TPPP, LINC00333, RIN3. IGFBP/IGFBP3, IZUMO1/MAMSTR and ZBTB46/STMN3) with possible association with ME/CFS which require further follow-up in future studies in order to assess whether they are real findings or not.

Interestingly, these genes are expressed in disease-relevant tissue, e.g. brain, nerve, skeletal muscle and blood, including immune cells (subgroups of T cells, B cells, NK cells and monocytes).

Furthermore, several of the ME/CFS associated SNP genotypes are associated with differential expression levels of these genes. Although we could not identify statistically convincing associations with genetic variants across the three cohorts, we believe that our data sets and analysis represent an important step in the ME/CFS research field.

Our study demonstrated that for the future understanding of the genetic architecture of ME/CFS much larger studies are required to established reliable associations.

In paper III, we wanted to investigate previous findings from a genome wide association study of 42 ME/CFS patients who reported significant association with two SNPs in the T cell receptor alpha (TRA) locus (P-value<5×10-8).

In order to replicate these previously reported findings, we used a large Norwegian ME/CFS cohort (409 cases and 810 controls) and data from the UK Biobank (2105 cases and 4786 controls). We examined a number of SNPs in the TRA locus, including the two previous ME/CFS-associated variants, rs11157573 and rs17255510. No statistically significant associations were observed in either the Norwegian cohort or UK biobank cohorts.

Nevertheless, other SNPs in the region showed weak signs of association (P-value <0.05) in the UK Biobank cohort and meta-analyzes of Norwegian and UK Biobank cohorts, but did not remain associated after applying correction for multiple testing. Thus, we could not confirm associations with genetic variants in the TRA locus in this study.

Source: Riad Hajdarevic. PhD thesis (University of Oslo) Electronic copies must be ordered. https://www.med.uio.no/klinmed/english/research/news-and-events/events/disputations/2022/hajdarevic-riad.html

General theory of inflammation: patient self-administration of hydrocortisone safely achieves superior control of hydrocortisone-responding disorders by matching dosage with symptom intensity

Abstract:

Objective: To determine if patient self-administration of hydrocortisone will safely achieve superior symptom control for all hydrocortisone-responding disorders as it does for Addison’s disease and rheumatoid arthritis.

Methods: Two thousand four hundred and twenty-eight participants with hydrocortisone-responding disorders were brought to a minimum symptom state using daily administered hydrocortisone tablets in a 24-week, open study. Thereafter, participants used 5-day, low-dose hydrocortisone regimens to quench subsequent disorder exacerbations (flares) to maintain the minimum symptom state. Stressors such as emotional traumas, infections, allergies, and injuries were minimized to reduce disorder intensity, hydrocortisone consumption, and participant discomfort.

Results: Two thousand fifteen participants, 601 with fibromyalgia, 579 with osteoarthritis, 246 with rheumatoid arthritis, 226 with undifferentiated arthritis, 75 with back pain, 51 with Parkinson’s disease, 44 with polymyalgia rheumatica, 25 with neuropathy, 25 with chronic fatigue syndrome, 25 with dementia, 21 with migraine headache, 19 with multiple sclerosis, and 78 with other disorders completed the 24-week study to achieve a composite average symptom improvement of 76% with equal response rates. The participants averaged ingesting 12 mg of hydrocortisone per day. No significant adverse reactions were observed.

Conclusions: Patient self-administration of hydrocortisone safely achieves superior symptom control for 38 hydrocortisone-responding disorders at equal rates and symptom improvements to confirm and amplify an earlier double-blind study finding on rheumatoid arthritis. These results are consistent with the body having an inflammation control system and chronic inflammation being a disorder unto itself with differing symptoms sets dependent on its location.

Clinical Trials Government Identifier: NCT03558971.

Source: Irwin JB, Baldwin AL, Stenberg VI. General theory of inflammation: patient self-administration of hydrocortisone safely achieves superior control of hydrocortisone-responding disorders by matching dosage with symptom intensity. J Inflamm Res. 2019 Jun 13;12:161-166. doi: 10.2147/JIR.S195165. eCollection 2019. https://www.dovepress.com/general-theory-of-inflammation-patient-self-administration-of-hydrocor-peer-reviewed-article-JIR (Full article)

MicroRNAs as biomarkers of pain intensity in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Numerous experimental models have shown that microRNAs play an important role in regulating pain-processing in clinical pain disorders. In this study, we evaluated a set of micro-RNAs as diagnostic biomarkers of pain intensity in adolescents with chronic fatigue syndrome (CFS). We then correlated the expression of these microRNAs with the levels of inflammatory markers and pain-related comorbidities in adolescents with CSF and healthy controls (HCs).

METHODS: A total of 150 adolescents, aged 12-18 years, participated in this study between April 2016 and April 2017. The participants were classified into two groups: adolescents with CFS (n=100) and HCs (n=50). RT-PCR was used to evaluate the expression of miR-558, miR-146a, miR-150, miR-124, and miR-143. Immunoassay analysis was used to assess the levels of immune inflammatory markers IL-6, TNF-α, and COX-2.

RESULTS: Adolescents with CFS showed significantly higher pain thresholds than comparable non-fatigued HCs. Also, enjoy of life and relation to others as the life domains, showed lower pain interference in CFS patients. Differential expression of miR-558, miR-146a, miR-150, miR-124, and miR-143 was significantly down regulated and notably interfered with pain intensity and frequency in patients with CFS. Also, the expression of these miRNAs was significantly correlated with that of IL-6, TNF-α, and COX-2, which have been shown to mediate pain intensity in patients with CFS.

Girls with CSF showed significantly decreased expression levels of these miRNAs compared with the levels of boys with CSF. Girls with CSF also showed increased expression of inflammatory pain-related markers IL-6, TNF-α, and COX-2, compared with the levels of boys with CSF

CONCLUSIONS: The intensity and consequences of pain were influenced by differential expression of miR-558, miR-146a, miR-150, miR-124, and miR-143, which was directly, associated with higher expression of immune inflammatory related genes TNFα, IL-6, and COX-2 in adolescences with CFS. Further studies of larger patient cohorts will help clarify the role of miRNAs in the pathogenesis of CFS.

Source: Al-Rawaf HA, Alghadir AH, Gabr SA. MicroRNAs as biomarkers of pain intensity in patients with chronic fatigue syndrome. Pain Pract. 2019 Jul 8. doi: 10.1111/papr.12817. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31282597

Long Term Follow up of Young People With Chronic Fatigue Syndrome Attending a Pediatric Outpatient Service

Abstract:

Aim: To determine the reported duration of illness, the functional and educational long-term outcomes, predictive factors for recovery and seek feedback regarding management in pediatric/adolescent myalgic encepahalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods: A cohort observational study of 784 young people, mean age 14.6 (6-18) years, with ME/CFS diagnosed at a specialist pediatric hospital and receiving regular care, was conducted with follow-up for a mean 8 (range 1-21) years after onset. Baseline symptoms, history, depression and anxiety questionnaires were available from 418. The remaining 366, did not have similar standardized baseline information. Questionnaires requested functional rating, persistent symptoms, duration of illness if “recovered,” social engagement and school/work attendance. Feedback was sought regarding management, support services, useful information, helpful interventions or personnel and use of alternative therapies. Reported recovery and function were compared with baseline information and between the two groups.

Results: Follow-up data were returned from 81.8%. There was no significant difference in functional score (if reported recovery) or illness duration related to provision of baseline data. The mean duration of illness was 5 (range 1-15) years in the 50% who reported recovery. By 5 years 38% and by 10 years 68% reported recovery. At 10 years the mean functional score was 8/10 (range 2-10) with 5% scoring <6. Depression, anxiety or severity of illness at diagnosis was not predictive of non-recovery. Designing and monitoring their own management plan that included educational, social, physical and enjoyable activities, as well as having symptom management and understanding professionals were highly valued. However, remaining engaged in an education system that flexibly accommodated their illness and aspirations was consistently reported as crucial for long term functioning.

Conclusions: ME/CFS in young people has a mean duration of 5 years (1-15) with 68% reporting recovery by 10 years. All improved functionally with 5% remaining very unwell and a further 20% significantly unwell. There were no obvious baseline predictors for recovery. However, depression, anxiety, orthostatic intolerance and to a lesser extent pain at follow up were identified as hampering recovery or function. Supportive professionals, remaining engaged in education and management strategies were identified as helpful.

Source: Rowe KS. Long Term Follow up of Young People With Chronic Fatigue Syndrome Attending a Pediatric Outpatient Service. Front Pediatr. 2019 Feb 21;7:21. doi: 10.3389/fped.2019.00021. eCollection 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6393360/ (Full article)

Increased risk of chronic fatigue syndrome following burn injuries

Abstract:

BACKGROUND: The overlapping symptoms and pathophysiological similarities between burn injury and chronic fatigue syndrome (CFS) are noteworthy. Thus, this study explores the possible association between burn injury and the subsequent risk of CFS.

METHOD: We used data from the Taiwan National Health Insurance system to address the research topic. The exposure cohort comprised of 17,204 patients with new diagnoses of burn injury. Each patient was frequency matched according to age, sex, index year, and comorbidities with four participants from the general population who did not have a history of CFS (control cohort). Cox proportional hazards regression analysis was conducted to estimate the relationship between burn injury and the risk of subsequent CFS.

RESULT: The incidence of CFS in the exposure and control cohorts was 1.61 and 0.86 per 1000 person-years, respectively. The exposure cohort had a significantly higher overall risk of subsequent CFS than did the control cohort (adjusted hazard ratio [HR] = 1.48, 95% confidence interval [CI] = 1.41-1.56). The risk of CFS in patients with burn injury in whichever stratification (including sex, age, and comorbidity) was also higher than that of the control cohort.

CONCLUSION: The findings from this population-based retrospective cohort study suggest that thermal injury is associated with an increased risk of subsequent CFS and provided a point of view suggesting burn injuries in sun- exposed areas such as the face and limbs had greater impact on subsequent development of CFS compared with trunk areas. In addition, extensively burned areas and visible scars were predictors of greater physiological and psychosocial that are needed to follow-up in the long run.

Source: Tsai SY, Lin CL, Shih SC, Hsu CW, Leong KH, Kuo CF, Lio CF, Chen YT, Hung YJ, Shi L. Increased risk of chronic fatigue syndrome following burn injuries. J Transl Med. 2018 Dec 5;16(1):342. doi: 10.1186/s12967-018-1713-2. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-018-1713-2 (Full article)

The Abnormal Cardiac Index and Stroke Volume Index Changes During a Normal Tilt Table Test in ME/CFS Patients Compared to Healthy Volunteers, are Not Related to Deconditioning

Abstract:

1.1 Background. A small study in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) patients undergoing tilt testing, showed that, despite a normal tilt test, stroke volumes and cardiac output were lower than in healthy volunteers. Moreover, it was suggested that this difference was related to deconditioning of patients. Aim of the study. We performed table testing in 150 ME/CFS patients. Stroke volumes and cardiac output were related to the severity of the disease.

1.2 Methods and results. In the patients the severity of the disease was clinically evaluated according to the ME criteria and scored as mild, moderate or severe disease. In a subgroup of 109 patients this clinical diagnosis was confirmed by the physical functioning score of the Rand-36 questionnaire. Significantly lower physical functioning scores (indicating worse functioning) were observed in the more severely affected patients. Stroke Volume Index (SVI) and Cardiac Index (CI) were measured by suprasternal aortic Doppler imaging in the supine position, prior to the tilt, and twice during the tilt. Thirty-seven healthy volunteers underwent the same tilt protocol. In all patients and all healthy volunteers, a normal heart rate and blood pressure response was observed during the tilt. The decreases in SVI and CI during the tilt was significantly larger in patients compared to the SVI and CI decrease in HV. The decrease in SVI and CI were similar and not significantly different between the mild, moderate, and severe ME groups.

1.3 Conclusions. During a normal tilt table test decreases in SVI and CI decrease are significantly greater in ME/CFS patients than in HV, consistent with previous work. The absence of differences between patients with mild, moderate, and severe ME/CFS suggests that the decreases in stroke volumes and cardiac output are not related to deconditioning. Other factors like decreased blood volumes and autonomic dysfunction may cause this difference in the hemodynamic response between ME/CFS patients and HV.

3. Abbreviations

BMI : Body Mass Index

BSA : Body Surface Area

CFS : Chronic Fatigue Syndrome

CI : Cardiac Index

DBP : Diastolic Blood Pressure

HR : Heart Rate

HUT : Head-Up Tilt Test

HV : Healthy Volunteers

IOM : Institute of Medicine

MAP : Mean Blood Pressure

ME : Myalgic Encephalomyelitis

NMH : Neurally Mediated Hypotension

Normal BPHR : normal Blood Pressure and Heart Rate Response During HUT

OI : Orthostatic Intolerance

R36 Phys Funct : Rand-36 Physical Functioning Score

SBP : Systolic Blood Pressure

SVI : Stroke Volume Index

SVRI : Systemic Vascular Resistance Index

VTI : Time-Velocity Integral

Source: van Campen CMC, Visser FC (2018) The Abnormal Cardiac Index and Stroke Volume Index Changes During a Normal Tilt Table Test in ME/CFS Patients Compared to Healthy Volunteers, are Not Related to Deconditioning. J Thrombo Cir: JTC -107. DOI: 10.29011/ JTC -107. 000007 https://www.gavinpublishers.com/articles/Research-Article/Journal-of-Thrombosis-and-Circulation/The-Abnormal-Cardiac-Index-and-Stroke-Volume-Index-Changes-During-a-Normal-Tilt-Table-Test-in-ME-CFS-Patients-Compared-to-Healthy-Volunteers-are-Not-Related-to-Deconditioning (Full article)