ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

1681–1700 of 6,209 studies

E2 ModerateCohortPEM not requiredObservational

Evolving phenotypes of non-hospitalized patients that indicate long COVID.

Estiri, Hossein, Strasser, Zachary H, Brat, Gabriel A et al.·BMC medicine·2021

This study looked at medical records from over 96,000 people to identify which health problems are more common in people who had COVID-19 compared to those who didn't. Researchers found that certain symptoms and conditions—including loss of taste and smell, hair loss, chest pain, extreme tiredness, shortness of breath, pneumonia, and new-onset diabetes—appear more frequently in COVID-19 survivors months after infection. Younger people under 65 developed more of these long-term problems than older adults.

Cognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Comorbidities in a Nationwide, Heterogenous Population of Veterans with Interstitial Cystitis/Bladder Pain Syndrome.

Laden, Bethany F, Bresee, Catherine, De Hoedt, Amanda et al.·Urology·2021

This study looked at how often people with bladder pain syndrome (IC/BPS) also have other health conditions, using data from a large group of veterans. Researchers found that people with IC/BPS are much more likely to have multiple overlapping conditions—including chronic fatigue syndrome, fibromyalgia, IBS, and migraines—as well as mental health challenges like depression and trauma. These patterns were especially strong in women.

E2 ModerateCohortPEM unclearCross-Sectional

Characterizing long COVID in an international cohort: 7 months of symptoms and their impact.

Davis, Hannah E, Assaf, Gina S, McCorkell, Lisa et al.·EClinicalMedicine·2021

This study surveyed nearly 3,800 people from around the world who had long-lasting COVID-19 symptoms lasting more than 28 days. By seven months after illness onset, most participants had not fully recovered and experienced an average of 56 symptoms affecting multiple body systems. The three most persistent symptoms were fatigue, post-exertional malaise (feeling worse after activity), and cognitive problems, with nearly 86% experiencing relapses triggered by exercise, physical activity, mental stress, or other exertion.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Potential role of microbiome in Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME).

Lupo, Giuseppe Francesco Damiano, Rocchetti, Gabriele, Lucini, Luigi et al.·Scientific reports·2021

This study looked at the bacteria living in the gut and mouth of people with ME/CFS compared to healthy people. Researchers found that people with ME/CFS have different types and amounts of bacteria in their intestines, including fewer beneficial bacteria and more of certain harmful ones. They also found differences in the chemical makeup of patients' stool samples. These differences suggest that gut bacteria imbalance may play a role in ME/CFS, though scientists don't yet know if this is a cause or a result of the illness.

E2 ModerateCohortPEM not requiredCross-Sectional

A retrospective cross-sectional study on tinnitus prevalence and disease associations in the Dutch population-based cohort Lifelines.

Schubert, Nick M A, Rosmalen, Judith G M, van Dijk, Pim et al.·Hearing research·2021

This study looked at how common tinnitus (ringing in the ears) is in a large group of Dutch adults and found that about one-third experience it at some point. The researchers discovered that tinnitus is linked to various conditions including hearing problems, heart issues, depression, and notably, chronic fatigue syndrome (ME/CFS). Understanding these connections may help doctors better treat tinnitus and related conditions.

E2 ModerateCohortPEM unclearObservational

Delineating the Association Between Soluble CD26 and Autoantibodies Against G-Protein Coupled Receptors, Immunological and Cardiovascular Parameters Identifies Distinct Patterns in Post-Infectious vs. Non-Infection-Triggered Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Szklarski, Marvin, Freitag, Helma, Lorenz, Sebastian et al.·Frontiers in immunology·2021

This study looked at a protein called sCD26 in people with ME/CFS to understand how it relates to immune system problems and heart function issues. Researchers found that people with ME/CFS triggered by an infection had different patterns of immune problems linked to low sCD26 levels compared to people whose ME/CFS started without an infection. The findings suggest that infection-related and non-infection-related ME/CFS may involve different biological mechanisms.

Immune System

E2 ModerateCohortPEM not requiredLongitudinal

Inflammation-type dysbiosis of the oral microbiome associates with the duration of COVID-19 symptoms and long COVID.

Haran, John P, Bradley, Evan, Zeamer, Abigail L et al.·JCI insight·2021

This study looked at bacteria in the mouth of people with COVID-19 to understand why some people develop long COVID. Researchers found that people with long COVID had higher levels of inflammation-causing bacteria, particularly types called Prevotella and Veillonella. Interestingly, the oral bacteria patterns in long COVID patients resembled those seen in chronic fatigue syndrome patients, suggesting the microbiome may play a role in prolonged illness.

Immune System

E2 ModerateBehavioralPEM unclearCross-Sectional

Anticipation of and response to exercise in adolescents with CFS: An experimental study.

Loades, M E, Chalder, T, Smakowski, A et al.·Journal of psychosomatic research·2021

This study looked at how adolescents with ME/CFS approach and perform a simple exercise task (standing up and sitting down repeatedly) compared to healthy teenagers and those with asthma. Teens with ME/CFS took longer to complete the task, expected to do worse beforehand, felt the effort was much harder, and felt more anxious about it—patterns that parents noticed too. The researchers suggest that difficult past experiences with exercise may lead to lower confidence and worry that affects how people with ME/CFS approach physical activity.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Associations between the gut microbiome and fatigue in cancer patients.

Hajjar, Joud, Mendoza, Tito, Zhang, Liangliang et al.·Scientific reports·2021

Researchers studied 88 cancer patients to see if the bacteria living in their gut were connected to cancer-related fatigue. They found that certain beneficial bacteria (Eubacterium hallii) were linked to lower fatigue levels, while other bacteria (Cosenzaea) were linked to higher fatigue. This suggests that the mix of gut bacteria might play a role in how tired cancer patients feel, opening the door to new treatments.

Gut Microbiome

E2 ModerateCohortPEM requiredCase-Control

Fine mapping of the major histocompatibility complex (MHC) in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) suggests involvement of both HLA class I and class II loci.

Hajdarevic, Riad, Lande, Asgeir, Rekeland, Ingrid et al.·Brain, behavior, and immunity·2021

This study looked at genes related to the immune system in people with ME/CFS to understand why some people develop the condition. Researchers compared genetic markers in 427 Norwegian ME/CFS patients with 480 healthy controls and found two specific genetic regions associated with ME/CFS—one involving immune system genes that present antigens to cells, and another in a different immune region. These findings suggest the immune system's ability to recognize and respond to threats may play a role in ME/CFS.

Immune System

E2 ModerateCohortPEM unclearCase-Control

Reduced Parasympathetic Reactivation during Recovery from Exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Van Oosterwijck, Jessica, Marusic, Uros, De Wandele, Inge et al.·Journal of clinical medicine·2021

This study examined how the nervous system controls heart rate and other body functions in ME/CFS patients compared to healthy people, both at rest and after exercise. Researchers found that while ME/CFS patients had normal nerve function at rest, their bodies had difficulty recovering after exercise—specifically, their parasympathetic nervous system (the 'rest and digest' system) didn't reactivate properly. This delayed recovery is concerning because similar patterns in other diseases are linked to worse health outcomes.

Post-Exertional Malaise

E2 ModerateBehavioralPEM not requiredCross-Sectional

Prevalence and correlates of chronic fatigue syndrome and post-traumatic stress disorder after the outbreak of the COVID-19.

Simani, Leila, Ramezani, Mahtab, Darazam, Ilad Alavi et al.·Journal of neurovirology·2021

This study looked at whether people who survived COVID-19 developed chronic fatigue syndrome (ME/CFS) or PTSD within 6 months of infection. Among 120 COVID-19 survivors in Iran, about 2.5% met the criteria for ME/CFS and 5.8% showed signs of PTSD. Interestingly, the researchers found that having PTSD was not linked to developing ME/CFS in these patients.

Long COVID Overlap

E2 ModerateBehavioralPEM unclearCross-Sectional

How common are depression and anxiety in adolescents with chronic fatigue syndrome (CFS) and how should we screen for these mental health co-morbidities? A clinical cohort study.

Loades, Maria E, Read, Rebecca, Smith, Lucie et al.·European child & adolescent psychiatry·2021

This study looked at how common depression and anxiety are in teenagers with ME/CFS. Researchers interviewed 164 young people with ME/CFS and their parents using detailed diagnostic interviews and questionnaires. They found that about 1 in 3 teenagers had depression or anxiety, which is higher than expected. However, the questionnaires commonly used to screen for these conditions were not always accurate at detecting problems in this group, so doctors need to be careful and do thorough assessments rather than relying on questionnaires alone.

E2 ModerateCohortPEM unclearCross-Sectional

Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long-Haul COVID-19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Campen, C Linda M C van, Rowe, Peter C, Visser, Frans C·Medicina (Kaunas, Lithuania)·2021

This study compared people with long-haul COVID-19 to people with ME/CFS to see if they experience similar problems with dizziness and blood flow when standing up. Researchers found that long-haul COVID patients had very similar symptoms to ME/CFS patients and showed even greater reductions in blood flow to the brain during tilt testing. The findings suggest that COVID-19 infection may trigger ME/CFS-like illness in some people.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCross-Sectional

Clinical Profile and Aspects of Differential Diagnosis in Patients with ME/CFS from Latvia.

Krumina, Angelika, Vecvagare, Katrine, Svirskis, Simons et al.·Medicina (Kaunas, Lithuania)·2021

This study looked at 65 people with ME/CFS in Latvia to understand their main symptoms and how the condition differs from simple tiredness. Researchers found that people with ME/CFS commonly experience fatigue, muscle pain, joint pain, and sleep problems—more often than people without ME/CFS. When patients had other health conditions alongside ME/CFS, their symptoms tended to be more severe.

Pain and SensitizationSleepDiagnostics

E2 ModerateCohortPEM unclearCross-Sectional

A Comprehensive Examination of Severely Ill ME/CFS Patients.

Chang, Chia-Jung, Hung, Li-Yuan, Kogelnik, Andreas M et al.·Healthcare (Basel, Switzerland)·2021

This study examined severely ill ME/CFS patients who are mostly housebound or bedbound—a group that hasn't received much research attention. Researchers found that fatigue, pain, and thinking difficulties were the most common complaints, and patients showed distinct sleep problems and hormone imbalances. The study suggests that ME/CFS and long COVID may share similar mechanisms, meaning treatments discovered for one condition could potentially help the other.

Long COVID OverlapPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Comparison of the finger plethysmography derived stroke volumes by Nexfin CO Trek and suprasternal aortic Doppler derived stroke volume measurements in adults with myalgic encephalomyelitis/chronic fatigue syndrome and in healthy controls.

van Campen, C Linda M C, Verheugt, Freek W A, Rowe, Peter C et al.·Technology and health care : official journal of the European Society for Engineering and Medicine·2021

This study compared two different ways of measuring how much blood the heart pumps with each beat during a tilt table test (where patients lie down then are tilted upright). Researchers tested 154 ME/CFS patients and 39 healthy people using finger cuff measurements and ultrasound of the heart. They found that the finger cuff method gave higher readings than ultrasound, but after adjusting the finger cuff numbers to match ultrasound values, the device became reliable enough to track changes during tilt testing.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCross-Sectional

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Major Impact on Lives of Both Patients and Family Members.

Brittain, Esme, Muirhead, Nina, Finlay, Andrew Y et al.·Medicina (Kaunas, Lithuania)·2021

This study looked at how ME/CFS affects the quality of life of patients and their family members using two surveys. The researchers found that ME/CFS seriously damages patients' quality of life, particularly in physical health, and also significantly impacts the wellbeing of partners and family members who care for them. The study shows that family members experience worry, sadness, and difficulty maintaining normal family activities because of their loved one's illness.

E2 ModerateCohortPEM unclearCross-Sectional

Cortical autonomic network connectivity predicts symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Zinn, Mark A, Jason, Leonard A·International journal of psychophysiology : official journal of the International Organization of Psychophysiology·2021

This study looked at how the brain controls the autonomic nervous system (the part that manages heart rate, breathing, and other automatic functions) in people with ME/CFS. Researchers used special brain recordings to measure electrical activity in 34 ME/CFS patients and 34 healthy people at rest, then looked for differences in how different brain regions communicate with each other. They found that people with ME/CFS had different patterns of brain communication, and these differences were connected to specific symptoms like fatigue, thinking problems, and pain.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCross-Sectional

Perceptions of European ME/CFS Experts Concerning Knowledge and Understanding of ME/CFS among Primary Care Physicians in Europe: A Report from the European ME/CFS Research Network (EUROMENE).

Cullinan, John, Pheby, Derek F H, Araja, Diana et al.·Medicina (Kaunas, Lithuania)·2021

ME/CFS experts across Europe were asked what they think family doctors know about ME/CFS and how to help them understand it better. The experts reported serious concerns: about 60% of ME/CFS patients go undiagnosed because family doctors lack knowledge about the condition, don't believe it's real, or don't know how to manage it. Most experts agreed that better training for doctors at all levels would help.

Diagnostics

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Evolving phenotypes of non-hospitalized patients that indicate long COVID.

Comorbidities in a Nationwide, Heterogenous Population of Veterans with Interstitial Cystitis/Bladder Pain Syndrome.

Characterizing long COVID in an international cohort: 7 months of symptoms and their impact.

Potential role of microbiome in Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME).

A retrospective cross-sectional study on tinnitus prevalence and disease associations in the Dutch population-based cohort Lifelines.

Delineating the Association Between Soluble CD26 and Autoantibodies Against G-Protein Coupled Receptors, Immunological and Cardiovascular Parameters Identifies Distinct Patterns in Post-Infectious vs. Non-Infection-Triggered Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Inflammation-type dysbiosis of the oral microbiome associates with the duration of COVID-19 symptoms and long COVID.

Anticipation of and response to exercise in adolescents with CFS: An experimental study.

Associations between the gut microbiome and fatigue in cancer patients.

Fine mapping of the major histocompatibility complex (MHC) in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) suggests involvement of both HLA class I and class II loci.

Reduced Parasympathetic Reactivation during Recovery from Exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Prevalence and correlates of chronic fatigue syndrome and post-traumatic stress disorder after the outbreak of the COVID-19.

How common are depression and anxiety in adolescents with chronic fatigue syndrome (CFS) and how should we screen for these mental health co-morbidities? A clinical cohort study.

Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long-Haul COVID-19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Clinical Profile and Aspects of Differential Diagnosis in Patients with ME/CFS from Latvia.

A Comprehensive Examination of Severely Ill ME/CFS Patients.

Comparison of the finger plethysmography derived stroke volumes by Nexfin CO Trek and suprasternal aortic Doppler derived stroke volume measurements in adults with myalgic encephalomyelitis/chronic fatigue syndrome and in healthy controls.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Major Impact on Lives of Both Patients and Family Members.

Cortical autonomic network connectivity predicts symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Perceptions of European ME/CFS Experts Concerning Knowledge and Understanding of ME/CFS among Primary Care Physicians in Europe: A Report from the European ME/CFS Research Network (EUROMENE).

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