Reproducibility of Measurements Obtained During Cardiopulmonary Exercise Testing in Individuals With Fatiguing Health Conditions – A Case Series

Abstract:

Purpose: Measurements obtained during maximal cardiopulmonary exercise testing (CPET) demonstrate high test–retest reliability, which indicates low error variance. However, measurements obtained from people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) may depart from typically observed high reproducibility, which could represent functionally relevant biological variability that is characteristic of the underlying pathophysiology. The purpose of this case series was to document individual experiences with test–retest variability in CPET measurements in individuals with ME/CFS compared with other fatiguing health conditions.

Methods: In this case series, 6 women matched for age and body mass index underwent 2 maximal CPETs spaced 24 hours apart. Clients comprised 1 sedentary individual without fatigue, 1 active individual without fatigue, 1 individual with multiple sclerosis (MS), 1 individual diagnosed with HIV, 1 individual with ME/CFS and low maximal volume of oxygen consumed (VO2max), and 1 high-functioning individual with ME/CFS and high VO2max. Percent change in CPET measurements between tests was calculated for each client.

Results: Nondisabled clients and clients with MS and HIV reproduced or improved in their volume of oxygen consumed (VO2), workload (WL), heart rate (HR), and minute ventilation (VE) at ventilatory anaerobic threshold (VAT) and at peak exercise (except peak WL and VE for the individual with HIV). Neither individual with ME/CFS reproduced VO2, WL, HR, or VE at VAT within literature estimates.

Conclusions: Measurements during CPET for individual patients may relate to potential condition-specific deficits in cardiac, pulmonary, and metabolic functioning.

Source: Larson, Benjamin PT, DPT1; Davenport, Todd E. PT, DPT, MPH, OCS2,3; Stevens, Staci R. MA3; Stevens, Jared BS3; Van Ness, J. Mark PhD3,4; Snell, Christopher R. PhD3. Reproducibility of Measurements Obtained During Cardiopulmonary Exercise Testing in Individuals With Fatiguing Health Conditions: A Case Series. Cardiopulmonary Physical Therapy Journal: October 2019 – Volume 30 – Issue 4 – p 145-152 doi: 10.1097/CPT.0000000000000100 https://journals.lww.com/cptj/Abstract/2019/10000/Reproducibility_of_Measurements_Obtained_D%20uring.4.aspx

An online survey of pelvic congestion support group members regarding comorbid symptoms and syndromes

Abstract:

Objectives: Patients with pelvic congestion syndrome (PCS) often report overlapping somatic symptoms and syndromes. The objective of this study was to explore the prevalence of co-existing symptoms and self-reported syndrome diagnoses among women with PCS and to inform future research hypotheses.

Methods: A brief online survey was offered to members of a PCS support group website. Responses were assessed for self-reported co-existing symptoms and formal diagnoses, including: chronic fatigue syndrome, fibromyalgia, postural tachycardia syndrome, irritable bowel syndrome, migraines, interstitial cystitis, and temporomandibular joint dysfunction.

Results: Of a total of 6000 members, there were 398 respondents; 232 (59%) had not yet been treated for PCS. Among these, the most prevalent co-existing symptoms were as follows: severe fatigue (72%), dizziness (63%), IBS symptoms (61%), brain fog (33%), migraines (49%), polyuria or dysuria (41%), excessive sweating (31%), TMJ pain (31%), and loose skin or lax joints (18%). These are much higher than reported for the general female population. The most commonly self-reported comorbid syndrome diagnoses for the overall group of 398 were: irritable bowel syndrome (29%), fibromyalgia (13%), spinal nerve problems (18%), interstitial cystitis (10%), postural tachycardia syndrome (9%), hypertension (11%), chronic fatigue syndrome (10%), and Ehlers-Danlos syndrome (6%). Other than with hypertension, these rates are variably higher than in the general population.

Conclusion: Several self-reported co-existing symptoms and syndromes are more prevalent in members of a PCS support group relative to the reported prevalence in the general population. More formal investigation is warranted to evaluate this finding and to investigate potential etiologic links. Ehlers-Danlos Syndrome appears to be common in self identifying PCS women.

Source: Smith SJ, Sichlau M, Sewall LE, Smith BH, Chen B, Khurana N, Rowe PC. An online survey of pelvic congestion support group members regarding comorbid symptoms and syndromes. Phlebology. 2022 Jul 13:2683555221112567. doi: 10.1177/02683555221112567. Epub ahead of print. PMID: 35831253. https://pubmed.ncbi.nlm.nih.gov/35831253/

Multi-organ impairment and Long COVID: a 1-year prospective, longitudinal cohort study

Abstract:

Importance Multi-organ impairment associated with Long COVID is a significant burden to individuals, populations and health systems, presenting challenges for diagnosis and care provision. Standardised assessment across multiple organs over time is lacking, particularly in non-hospitalised individuals.

Objective To determine the prevalence of organ impairment in Long COVID patients at 6 and at 12 months after initial symptoms and to explore links to clinical presentation.

Design This was a prospective, longitudinal study in individuals following recovery from acute COVID-19. We assessed symptoms, health status, and multi-organ tissue characterisation and function, using consensus definitions for single and multi-organ impairment. Physiological and biochemical investigations were performed at baseline on all individuals and those with organ impairment were reassessed, including multi-organ MRI, 6 months later.

Setting Two non-acute settings (Oxford and London).

Participants 536 individuals (mean 45 years, 73% female, 89% white, 32% healthcare workers, 13% acute COVID-19 hospitalisation) completed baseline assessment (median: 6 months post-COVID-19). 331 (62%) with organ impairment or incidental findings had follow up, with reduced symptom burden from baseline (median number of symptoms: 10 and 3, at 6 and 12 months).

Exposure SARS-CoV-2 infection 6 months prior to first assessment.

Main outcome Prevalence of single and multi-organ impairment at 6 and 12 months post-COVID-19.

Results Extreme breathlessness (36% and 30%), cognitive dysfunction (50% and 38%) and poor health-related quality of life (EQ-5D-5L<0.7; 55% and 45%) were common at 6 and 12 months, and associated with female gender, younger age and single organ impairment. At baseline, there was fibro-inflammation in the heart (9%), pancreas (9%), kidney (15%) and liver (11%); increased volume in liver (7%), spleen (8%) and kidney (9%); decreased capacity in lungs (2%); and excessive fat deposition in the liver (25%) and pancreas (15%). Single and multi-organ impairment were present in 59% and 23% at baseline, persisting in 59% and 27% at follow-up.

Conclusion and Relevance Organ impairment was present in 59% of individuals at 6 months post-COVID-19, persisting in 59% of those followed up at 1 year, with implications for symptoms, quality of life and longer-term health, signalling need for prevention and integrated care of Long COVID.

Source: Andrea Dennis, Daniel J Cuthbertson, Dan Wootton, Michael Crooks, Mark Gabbay, Nicole Eichert, Sofia Mouchti, Michele Pansini, Adriana Roca-Fernandez, Helena Thomaides-Brears, Matt Kelly, Matthew Robson, Lyth Hishmeh, Emily Attree, Melissa Heightman, Rajarshi Banerjee, Amitava Banerjee. Multi-organ impairment and Long COVID: a 1-year prospective, longitudinal cohort study. medRxiv 2022.03.18.22272607; doi: https://doi.org/10.1101/2022.03.18.22272607  https://www.medrxiv.org/content/10.1101/2022.03.18.22272607v1.full.pdf (Full text)

Treatments of chronic fatigue syndrome and its debilitating comorbidities: a 12-year population-based study

Abstract:

Background: This study aims to provide 12-year nationwide epidemiology data to investigate the epidemiology and comorbidities of and therapeutic options for chronic fatigue syndrome (CFS) by analyzing the National Health Insurance Research Database.

Methods: 6306 patients identified as having CFS during the 2000-2012 period and 6306 controls (with similar distributions of age and sex) were analyzed.

Result: The patients with CFS were predominantly female and aged 35-64 years in Taiwan and presented a higher proportion of depression, anxiety disorder, insomnia, Crohn’s disease, ulcerative colitis, renal disease, type 2 diabetes, gout, dyslipidemia, rheumatoid arthritis, Sjogren syndrome, and herpes zoster. The use of selective serotonin receptor inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), Serotonin antagonist and reuptake inhibitors (SARIs), Tricyclic antidepressants (TCAs), benzodiazepine (BZD), Norepinephrine-dopamine reuptake inhibitors (NDRIs), muscle relaxants, analgesic drugs, psychotherapies, and exercise therapies was prescribed significantly more frequently in the CFS cohort than in the control group.

Conclusion: This large national study shared the mainstream therapies of CFS in Taiwan, we noticed these treatments reported effective to relieve symptoms in previous studies. Furthermore, our findings indicate that clinicians should have a heightened awareness of the comorbidities of CFS, especially in psychiatric problems.

Source: Leong KH, Yip HT, Kuo CF, Tsai SY. Treatments of chronic fatigue syndrome and its debilitating comorbidities: a 12-year population-based study. J Transl Med. 2022 Jun 11;20(1):268. doi: 10.1186/s12967-022-03461-0. PMID: 35690765. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03461-0  (Full study)

Symptom burden correlates to impairment of diffusion capacity and exercise intolerance in long COVID patients

Abstract:

After acute infection with the SARS-CoV-2 virus, a considerable number of patients remains symptomatic with pathological changes in various organ systems. This study aimed to relate the physical and mental burden of symptoms of long COVID patients to the findings of a somatic evaluation.

In patients with persistent long COVID symptoms three months after acute infection we assessed physical and mental health status using the SF-36 questionnaire. The cohort was dichotomised by the results (upper two quartiles vs. lower to quartiles) and compared with regard to transthoracic echocardiography, body plethysmography (including diffusion capacity), capillary blood gas analysis and 6-min walk test (6-MWT). From February 22 to September 13, 2021, 463 patients were prospectively examined, of which 367 completed the SF-36 questionnaire. A positive correlation between initial disease severity (need for hospitalization, intensive care medicine) and resulting symptom burden at follow-up could be demonstrated.

Patients with impaired subjective physical and mental status were significantly more likely to be women. There was a significant correlation between symptom severity and reduced exercise tolerance in the 6-MWT (495.6 ± 83.7 m vs 549.7 ± 71.6 m, p < 0.001) and diffusion capacity for carbon monoxide (85.6 ± 14.3% of target vs 94.5 ± 14.4, p < 0.001). In long COVID patients, initial disease severity is correlated with symptom burden after at least 3 months of follow-up. Highly symptomatic long COVID patients show impaired diffusion capacity and 6-MWT despite average or mildly affected mechanical lung parameters. It must be further differentiated whether this corresponds to a transient functional impairment or whether it is a matter of defined organ damage.

Source: Kersten, J., Wolf, A., Hoyo, L. et al. Symptom burden correlates to impairment of diffusion capacity and exercise intolerance in long COVID patients. Sci Rep 12, 8801 (2022). https://doi.org/10.1038/s41598-022-12839-5  https://www.nature.com/articles/s41598-022-12839-5 (Full text)

Restless legs syndrome is associated with long-COVID in women

Abstract:

Study Objectives: Sleep disturbance is common in long-COVID (LC). Restless legs syndrome (RLS) is characterized by sleep disturbance and has been reported after viral infections. Therefore, we evaluated RLS symptoms cross-sectionally in individuals with LC at both current and pre-COVID19 timepoints.

Methods: LC-focused Facebook adults were recruited for an online assessment of symptoms before COVID-19 infection and during their present LC state in a cross-sectional manner. The LC group documented baseline symptoms retrospectively. Questions were included about the presence/severity of RLS symptoms and assessments of fatigue, quality of life, and sleep apnea. A control group was recruited and included individuals ≥18 years of age who never had overt symptoms of COVID-19. Pregnancy was exclusion criteria for both groups.

Results: There were 136 LC participants (89.7% females, age 46.9 ±12.9 years) and 136 controls (65.4% females, age 49.2 ±15.5). RLS prevalence in LC-females was 5.7% pre-COVID-19 and 14.8% post-COVID-19 (p<0.01) vs. 6.7% in control-females. Severity of RLS was moderate in both groups. Logistic regression predicting post-COVID-19 RLS among LC-females failed to find significant effects of hospitalization, sleep apnea, neuropathic pain severity or use of antihistamines and antidepressants.

Conclusions: The baseline prevalence of RLS in LC-females was similar to the general population group as well as to patients in epidemiological studies. The prevalence significantly increased in the LC state. Post-infectious immunological mechanisms may be at play in the production for RLS symptoms.

Source: Leonard B. Weinstock, MD, FACG ; Jill B. Brook, MA ; Arthur S. Walters,  MD ;  Ashleigh Goris, RN, BSN, MPH, CIC, FAPIC ; Lawrence B. Afrin, MD ; Gerhard J. Molderings, MD. Restless legs syndrome is associated with long-COVID in women. Journal of Clinical Sleep Medicine. Published Online:January 25, 2022. https://doi.org/10.5664/jcsm.9898 https://jcsm.aasm.org/doi/pdf/10.5664/jcsm.9898 (Full study)

Long covid in adults discharged from UK hospitals after covid-19: a prospective, multicentre cohort study using the ISARIC WHO Clinical Characterisation Protocol

Abstract:

Background: This study sought to establish the long-term effects of Covid-19 following hospitalisation.

Methods: 327 hospitalised participants, with SARS-CoV-2 infection were recruited into a prospective multicentre cohort study at least 3 months post-discharge. The primary outcome was self-reported recovery at least ninety days after initial Covid-19 symptom onset. Secondary outcomes included new symptoms, disability (Washington group short scale), breathlessness (MRC Dyspnoea scale) and quality of life (EQ5D-5L).

Findings: 55% of participants reported not feeling fully recovered. 93% reported persistent symptoms, with fatigue the most common (83%), followed by breathlessness (54%). 47% reported an increase in MRC dyspnoea scale of at least one grade. New or worse disability was reported by 24% of participants. The EQ5D-5L summary index was significantly worse following acute illness (median difference 0.1 points on a scale of 0 to 1, IQR: -0.2 to 0.0). Females under the age of 50 years were five times less likely to report feeling recovered (adjusted OR 5.09, 95% CI 1.64 to 15.74), were more likely to have greater disability (adjusted OR 4.22, 95% CI 1.12 to 15.94), twice as likely to report worse fatigue (adjusted OR 2.06, 95% CI 0.81 to 3.31) and seven times more likely to become more breathless (adjusted OR 7.15, 95% CI 2.24 to 22.83) than men of the same age.

Interpretation: Survivors of Covid-19 experienced long-term symptoms, new disability, increased breathlessness, and reduced quality of life. These findings were present in young, previously healthy working age adults, and were most common in younger females.

Source: Sigfrid L, Drake TM, Pauley E, Jesudason EC, Olliaro P, Lim WS, Gillesen A, Berry C, Lowe DJ, McPeake J, Lone N, Munblit D, Cevik M, Casey A, Bannister P, Russell CD, Goodwin L, Ho A, Turtle L, O’Hara ME, Hastie C, Donohue C, Spencer RG, Donegan C, Gummery A, Harrison J, Hardwick HE, Hastie CE, Carson G, Merson L, Baillie JK, Openshaw P, Harrison EM, Docherty AB, Semple MG, Scott JT; ISARIC4C investigators. Long Covid in adults discharged from UK hospitals after Covid-19: A prospective, multicentre cohort study using the ISARIC WHO Clinical Characterisation Protocol. Lancet Reg Health Eur. 2021 Sep;8:100186. doi: 10.1016/j.lanepe.2021.100186. Epub 2021 Aug 6. PMID: 34386785; PMCID: PMC8343377. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8343377/ (Full text)

Covid-19: Middle aged women face greater risk of debilitating long term symptoms

Middle aged women have a higher risk of experiencing a range of debilitating ongoing symptoms, such as fatigue, breathlessness, muscle pain, anxiety, depression, and “brain fog” after hospital treatment for covid-19, suggest the findings of two unpublished studies available as preprints.

Seven in 10 patients admitted to hospital with covid-19 reported “long covid” symptoms an average of five months after discharge in the larger PHOSP-COVID study, and symptoms were more prevalent in women aged 40-60.1 White ethnicity, two or more comorbidities at admission, and receiving invasive ventilation while in hospital increased the risk, but severity of acute covid-19 disease did not seem to affect the likelihood of experiencing long covid symptoms.

Only 29% of the 1077 patients studied felt fully recovered when followed up, on average five months after discharge. Over a quarter had clinically significant symptoms of anxiety and depression, 12% had symptoms of post-traumatic stress disorder, 17% had at least mild cognitive impairment, 46% had lower physical performance than age and sex matched controls, and 20% had a new disability.

Before hospital admission 68% of patients had worked full time, but 18% of these had not returned to work and 19% had had to change their way of working because of longlasting effects.

The researchers grouped patients into four clusters according to the severity of their physical and mental symptoms post-covid: very severe (17% of patients), severe (21%), moderate with cognitive impairment (17%), and mild (46%).

Rachael Evans, National Institute for Health Research clinical scientist at the University of Leicester and a study author, said, “The symptoms are very real, but they don’t have a straightforward relationship with heart and lung damage, or certainly heart and lung damage can’t explain all the symptoms.”

Immune response

A smaller second study, from the International Severe Acute Respiratory and emerging Infections Consortium (ISARIC), found that women under 50 were five times less likely to report feeling recovered, twice as likely to report worse fatigue, seven times more likely to become more breathless, and more likely to have greater disability than men of the same age who had been admitted to hospital with covid-19.2 Disability usually affected memory, mobility, communication, vision, or hearing. More than half of the 327 patients assessed in this study did not feel fully recovered when followed up on average seven months later, and persistent symptoms were reported by 93.3%, with fatigue and breathlessness the most common.

Chris Brightling, professor of respiratory medicine at the University of Leicester and a PHOSP-COVID study researcher, speculated that sex based differences in the immune response may be responsible for the higher prevalence of long covid symptoms in women, noting that autoimmune diseases were more prevalent in women than in men at age 40-60.

“Maybe there’s a difference in the immune response acutely, such that men are more likely to have a more severe condition at the time of the infection,” he told a press conference at the Science Media Centre on 24 March. “It may be that the immune response is different in women, so you then have a continued inflammatory reaction that then leads to a higher likelihood of having long covid.”

Higher levels of C reactive protein, a marker of systemic inflammation, were seen in patients in the most severe long covid symptoms. Brightling said that a number of immune and chronic inflammatory conditions can also cause elevated C reactive protein.

About 450 000 people have been admitted to hospital with covid-19 in the UK, so a “very large” proportion of these would potentially be affected by long covid, he said, adding, “Clearly there’s an even larger number of people that have had covid in the community, and a portion of those will also have long covid.”

Source: Torjesen ICovid-19: Middle aged women face greater risk of debilitating long term symptoms doi:10.1136/bmj.n829 https://www.bmj.com/content/372/bmj.n829 (Full text)

Estimating total morbidity burden of COVID-19: relative importance of death and disability

Abstract:

Objective: Calculations of disease burden of COVID-19, used to allocate scarce resources, have historically considered only mortality. However, survivors often develop postinfectious ‘long-COVID’ similar to chronic fatigue syndrome; physical sequelae such as heart damage, or both. This paper quantifies relative contributions of acute case fatality, delayed case fatality, and disability to total morbidity per COVID-19 case.

Study design and setting: Healthy life years lost per COVID-19 case were computed as the sum of (incidence*disability weight*duration) for death and long-COVID by sex and 10-year age category in three plausible scenarios.

Results: In all models, acute mortality was only a small share of total morbidity. For lifelong moderate symptoms, healthy years lost per COVID-19 case ranged from 0.92 (male in his 30s) to 5.71 (girl under 10) and were 3.5 and 3.6 for the oldest females and males. At higher symptom severities, young people and females bore larger shares of morbidity; if survivors’ later mortality increased, morbidity increased most in young people of both sexes.

Conclusions: Under most conditions most COVID-19 morbidity was in survivors. Future research should investigate incidence, risk factors, and clinical course of long-COVID to elucidate total disease burden, and decisionmakers should allocate scarce resources to minimize total morbidity. WHAT IS NEW; KEY FINDINGS: : Under most plausible model scenarios, most COVID-19 morbidity (death + disability) is likely to be due to disability (‘long-COVID’) or delayed death due to organ damage, rather than immediate death. Only if long-COVID resolves (atypical of postinfectious syndromes) is morbidity higher in old than young WHAT THIS ADDS TO WHAT IS KNOWN: : While COVID-19 deaths are numerous, they likely cause less morbidity overall than does disability or organ damage in survivors. Morbidity is highest in females, especially those infected young.

What should change now: Scarce resources such as vaccines should be allocated to minimize morbidity rather than focusing solely on mortality. Data on long-COVID, especially its sex bias, should be collected and publicized.

Source: Smith MP. Estimating total morbidity burden of COVID-19: relative importance of death and disability. J Clin Epidemiol. 2021 Oct 26:S0895-4356(21)00339-5. doi: 10.1016/j.jclinepi.2021.10.018. Epub ahead of print. PMID: 34715312. https://pubmed.ncbi.nlm.nih.gov/34715312/

Female Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome or Idiopathic Chronic Fatigue: Comparison of Responses to a Two-Day Cardiopulmonary Exercise Testing Protocol

Abstract:

Introduction: Multiple studies have shown that peak oxygen consumption is reduced in the majority of ME/CFS patients, using the golden standard for measuring exercise intolerance: cardiopulmonary exercise testing (CPET). A 2-day CPET protocol has shown different results on day 2 in ME/CFS patients compared to sedentary controls. No comparison is known between ME/CFS and idiopathic chronic fatigue (ICF) for 2-day CPET protocols. We compared ME/CFS patients with patients with chronic fatigue who did not fulfil the ME/CFS criteria in a male population and hypothesized a different pattern of response would be present during the 2nd day CPET.

Methods: Fifty-one female patients with ICF completed a 2-day CPET protocol and were compared to an age/sex-matched group of 50 female ME/CFS patients. Measures of oxygen consumption (VO2), heart rate (HR), systolic and diastolic blood pressure, workload (Work), and respiratory exchange ratio (RER) were collected at maximal (peak) and ventilatory threshold (VT) intensities.

Results: Baseline characteristics for both groups were similar for age, BMI, BSA, and disease duration. A significance difference was present in the number of patients with fibromyalgia (seven ME/CFS patients vs zero ICF patients). Heart rate at rest and the RER did not differ significantly between CPET 1 and CPET 2. All other CPET parameters at the ventilatory threshold and maximum exercise differed significantly (p-value between 0.002 and <0.0001). ME/CFS patients showed a deterioration of performance on CPET2 as reflected by VO2 and workload at peak exercise and ventilatory threshold, whereas ICF patients showed improved performance on CPET2 with no significant change in peak workload.

Conclusion: This study confirms that female ME/CFS patients have a reduction in exercise capacity in response to a second day CPET. These results are similar to published results in female ME/CFS populations. Patients diagnosed with ICF show a different response on day 2, more similar to sedentary and healthy controls.

Source: van Campen CLMC, Visser FC. Female Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome or Idiopathic Chronic Fatigue: Comparison of Responses to a Two-Day Cardiopulmonary Exercise Testing Protocol. Healthcare (Basel). 2021 Jun 5;9(6):682. doi: 10.3390/healthcare9060682. PMID: 34198913. https://pubmed.ncbi.nlm.nih.gov/34198913/