Tag: carnitine

Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome

Abstract:

Background: Fatigue of unknown origin is a hallmark symptom in chronic fatigue syndrome (CFS) and is also found in 20% of hypothyroidism patients despite appropriate levothyroxine treatment. Here, we suggest that in these disorders, peripheral serotonin levels are low, and elevating them to normal range with L-carnitine is accompanied with reduced fatigue.

Methods: We conducted a retrospective analysis of follow-up clinical data (CFS N=12; hypothyroidism with fatigue N=40) where serum serotonin and fatigue levels were compared before vs. after 7 weeks of oral L-carnitine supplementation.

Results: After L-carnitine, serotonin increased (8-fold in CFS, Sig. = 0.002, 6-fold in hypothyroidism, Sig. < 0.001) whereas fatigue decreased (2-fold in both CFS and hypothyroidism, Sig. = 0.002 for CFS, Sig. < 0.001 for hypothyroidism). There was a negative correlation between serotonin level and fatigue (for CFS, rho = -0.49 before and -0.67 after L-carnitine; for hypothyroidism, rho = -0.24 before and -0.83 after L-carnitine).

Conclusions: These findings suggest a new link between low peripheral serotonin, L-carnitine, and fatigue.

Source: Tommi Raij, Kari Raij. Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome. Front. Endocrinol. Sec. Neuroendocrine Science, Volume 15 – 2024 | doi: 10.3389/fendo.2024.1358404 https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1358404/abstract

Advancing Research and Treatment: An Overview of Clinical Trials in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Future Perspectives

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, debilitating, and multi-faceted illness. Heterogenous onset and clinical presentation with additional comorbidities make it difficult to diagnose, characterize, and successfully treat. Current treatment guidelines focus on symptom management, but with no clear target or causative mechanism, remission rates are low, and fewer than 5% of patients return to their pre-morbid activity levels. Therefore, there is an urgent need to undertake robust clinical trials to identify effective treatments.
This review synthesizes insights from clinical trials exploring pharmacological interventions and dietary supplements targeting immunological, metabolic, gastrointestinal, neurological, and neuroendocrine dysfunction in ME/CFS patients which require further exploration. Additionally, the trialling of alternative interventions in ME/CFS based on reported efficacy in the treatment of illnesses with overlapping symptomology is also discussed. Finally, we provide important considerations and make recommendations, focusing on outcome measures, to ensure the execution of future high-quality clinical trials to establish clinical efficacy of evidence-based interventions that are needed for adoption in clinical practice.
Source: Seton KA, Espejo-Oltra JA, Giménez-Orenga K, Haagmans R, Ramadan DJ, Mehlsen J on behalf of the European ME Research Group for Early Career Researchers (Young EMERG). Advancing Research and Treatment: An Overview of Clinical Trials in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Future Perspectives. Journal of Clinical Medicine. 2024; 13(2):325. https://doi.org/10.3390/jcm13020325 https://www.mdpi.com/2077-0383/13/2/325 (Full text)

Conceptual foundations of acetylcarnitine supplementation in neuropsychiatric long COVID syndrome: a narrative review

Abstract:

Post-acute sequelae of COVID-19 can present as multi-organ pathology, with neuropsychiatric symptoms being the most common symptom complex, characterizing long COVID as a syndrome with a significant disease burden for affected individuals. Several typical symptoms of long COVID, such as fatigue, depressive symptoms and cognitive impairment, are also key features of other psychiatric disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and major depressive disorder (MDD). However, clinically successful treatment strategies are still lacking and are often inspired by treatment options for diseases with similar clinical presentations, such as ME/CFS.

Acetylcarnitine, the shortest metabolite of a class of fatty acid metabolites called acylcarnitines and one of the most abundant blood metabolites in humans can be used as a dietary/nutritional supplement with proven clinical efficacy in the treatment of MDD, ME/CFS and other neuropsychiatric disorders. Basic research in recent decades has established acylcarnitines in general, and acetylcarnitine in particular, as important regulators and indicators of mitochondrial function and other physiological processes such as neuroinflammation and energy production pathways.

In this review, we will compare the clinical basis of neuropsychiatric long COVID with other fatigue-associated diseases. We will also review common molecular disease mechanisms associated with altered acetylcarnitine metabolism and the potential of acetylcarnitine to interfere with these as a therapeutic agent. Finally, we will review the current evidence for acetylcarnitine as a supplement in the treatment of fatigue-associated diseases and propose future research strategies to investigate the potential of acetylcarnitine as a treatment option for long COVID.

Source: Helbing DL, Dommaschk EM, Danyeli LV, Liepinsh E, Refisch A, Sen ZD, Zvejniece L, Rocktäschel T, Stabenow LK, Schiöth HB, Walter M, Dambrova M, Besteher B. Conceptual foundations of acetylcarnitine supplementation in neuropsychiatric long COVID syndrome: a narrative review. Eur Arch Psychiatry Clin Neurosci. 2024 Jan 3. doi: 10.1007/s00406-023-01734-3. Epub ahead of print. PMID: 38172332. https://link.springer.com/article/10.1007/s00406-023-01734-3 (Full text)

A systematic review and meta-analysis of urinary biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifactorial illness that affects many body systems including the immune, nervous, endocrine, cardiovascular, and urinary systems. There is currently no universal diagnostic marker or targeted treatment for ME/CFS. Urine is a non-invasive sample that provides biomarkers that may have the potential to be used in a diagnostic capacity for ME/CFS. While there are several studies investigating urine-based biomarkers for ME/CFS, there are no published systematic reviews to summarise existing evidence of these markers. The aim of this systematic review was to compile and appraise literature on urinary-based biomarkers in ME/CFS patients compared with healthy controls.

Methods: Three databases: Embase, PubMed, and Scopus were searched for articles pertaining to urinary biomarkers for ME/CFS compared with healthy controls published between December 1994 to December 2022. The final articles included in this review were determined through application of specific inclusion and exclusion criteria. Quality and bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Case Control Studies. A meta-analysis according to Cochrane guidelines was conducted on select studies, in particular, those that investigate urinary free cortisol levels in ME/CFS patients compared to healthy controls using the program STATA 17.

Results: Twenty-one studies were included in this review. All of the studies investigated urinary-based markers in ME/CFS patients compared with healthy controls. The reported changes in urinary outputs include urinary free cortisol (38.10%), carnitine (28.6%), iodine (4.76%), and the metabolome (42.86%). In most cases, there was minimal overlap in the main outcomes measured across the studies, however, differences in urinary free cortisol between ME/CFS patients and healthy controls were commonly reported. Seven studies investigating urinary free cortisol were included in the meta-analysis. While there were significant differences found in urinary free cortisol levels in ME/CFS patients, there was also substantial heterogeneity across the included studies that makes drawing conclusions difficult.

Conclusions: There is limited evidence suggesting a consistent and specific potential urinary-based biomarker for ME/CFS. Further investigations using more standardised methodologies and more stringent case criteria may be able to identify pathophysiological differences with diagnostic potential in ME/CFS patients compared with healthy controls.

Source: Taccori A, Maksoud R, Eaton-Fitch N, Patel M, Marshall-Gradisnik S. A systematic review and meta-analysis of urinary biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). J Transl Med. 2023 Jul 5;21(1):440. doi: 10.1186/s12967-023-04295-0. PMID: 37408028; PMCID: PMC10320942. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10320942/ (Full text)

Carnitine Palmitoyl Transferase Deficiency in a University Immunology Practice

Abstract:

Purpose: This report describes the clinical manifestations of 35 patients sent to a University Immunology clinic with a diagnosis of fatigue and exercise intolerance who were identified to have low carnitine palmitoyl transferase activity on muscle biopsies.

Recent findings: All of the patients presented with fatigue and exercise intolerance and many had been diagnosed with fibromyalgia. Their symptoms responded to treatment of the metabolic disease. Associated symptoms included bloating, diarrhea, constipation, gastrointestinal reflux symptoms, recurrent infections, arthritis, dyspnea, dry eye, visual loss, and hearing loss. Associated medical conditions included Hashimoto thyroiditis, Sjogren’s syndrome, seronegative arthritis, food hypersensitivities, asthma, sleep apnea, and vasculitis. This study identifies clinical features that should alert physicians to the possibility of an underlying metabolic disease. Treatment of the metabolic disease leads to symptomatic improvement.

Source: Bax K, Isackson PJ, Moore M, Ambrus JL Jr. Carnitine Palmitoyl Transferase Deficiency in a University Immunology Practice. Curr Rheumatol Rep. 2020 Feb 14;22(3):8. doi: 10.1007/s11926-020-0879-9. PMID: 32067119. https://pubmed.ncbi.nlm.nih.gov/32067119/

Can l-carnitine reduce post-COVID-19 fatigue?

Abstract:

A significant number of patients infected with the new coronavirus suffer from chronic fatigue syndrome after COVID-19, and their symptoms may persist for months after the infection. Nevertheless, no particular treatment for post-disease fatigue has been found. At the same time, many clinical trials have shown the effectiveness of l-carnitine in relieving fatigue caused by the treatment of diseases such as cancer, MS, and many other diseases. Therefore, it can be considered as a potential option to eliminate the effects of fatigue caused by COVID-19, and its consumption is recommended in future clinical trials to evaluate its effectiveness and safety.

Source: Vaziri-Harami R, Delkash P. Can l-carnitine reduce post-COVID-19 fatigue? Ann Med Surg (Lond). 2022 Jan;73:103145. doi: 10.1016/j.amsu.2021.103145. Epub 2021 Dec 13. PMID: 34925826; PMCID: PMC8667465. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667465/ (Full text)

Plasma and Urinary Carnitine and Acylcarnitines in Chronic Fatigue Syndrome

Abstract:

Contradictory reports have suggested that serum free carnitine and acylcarnitine concentrations are decreased in patients with chronic fatigue syndrome (CFS) and that this is a cause of the muscle fatigue observed in these patients. Others have shown normal serum free carnitine and acylcarnitines in similar patients. We report here studies on free, total and esterified (acyl) carnitines in urine and blood plasma from UK patients with CFS and three control groups.

Plasma and timed urine samples were obtained from 31 patients with CFS, 31 healthy controls, 15 patients with depression and 22 patients with rheumatoid arthritis. Samples were analysed using an established radioenzymatic procedure for total, free and esterified (acyl) carnitine.

There were no significant differences in plasma or urinary total, free or esterified (acyl) carnitine between UK patients with CFS and the control groups or in renal excretion rates of these compounds. The data presented here show that, in the CFS patients studied, there are no significant abnormalities of free or esterified (acyl) carnitine. It is thus unlikely that abnormalities in carnitine homeostasis have any significant role in the aetiology of their chronic fatigue.

Source: Jones MG, Goodwin CS, Amjad S, Chalmers RA. Plasma and urinary carnitine and acylcarnitines in chronic fatigue syndrome. Clin Chim Acta. 2005 Oct;360(1-2):173-7. doi: 10.1016/j.cccn.2005.04.029. PMID: 15967423. https://pubmed.ncbi.nlm.nih.gov/15967423/

Investigating Fatigue and Exercise Intolerance in a University Immunology Clinic

Abstract:

Purpose: This manuscript reviews the experience of a University Immunology clinic with the evaluation of patients with idiopathic fatigue and exercise intolerance for the presence of metabolic disorders. Laboratory, biochemical and genetic studies were utilized in the evaluation.

Recent Findings: Of the 372 patients evaluated, 95% were found to have a treatable metabolic disorder. A defect in the glycogen storage pathway was found in 78 patients. Mitochondrial disorders were found in 258 patients. Myoadenylate deaminase deficiency was found in 7 patients. Various congenital myopathies were identified in 11 patients. Inflammatory myopathies were identified in 25 patients, 6 of whom had normal muscle enzymes on the initial evaluation.

Summary: The majority of patients (95%) referred with idiopathic fatigue and exercise intolerance after extensive evaluations were found to have underlying metabolic dysfunction. Frequently associated problems included gastrointestinal dysmotility disorders, recurrent infections, Raynaud’s, migraine headaches and various autoimmune diseases. Most patients showed symptomatic improvement with treatment of their metabolic dysfunction.

Source: Julian L A, Paul I, Molly M, John B, Lucia B. Investigating Fatigue and Exercise Intolerance in a University Immunology Clinic. Arch Rheum & Arthritis Res. 1(1): 2020. ARAR.MS.ID.000505. https://irispublishers.com/arar/fulltext/Investigating-Fatigue-and-Exercise-Intolerance-in-a-University.ID.000505.php (Full study)

Brain Science on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disease characterized by chronic, profound, disabling, and unexplained fatigue. A variety of studies have been performed to establish objective biomarkers of the disease, including positron emission tomography (PET) molecular imaging and neuro-functional imaging using magnetic resonance imaging (MRI) and magnetoencephalogram (MEG). In this chapter, we summarize the results from PET, MRI, and MEG imaging.

Regional cerebral blood flow and glucose utilization rates are decreased in patients with ME/CFS as compared with age- and sex-matched healthy subjects. Acetyl-L-carnitine uptake into the releasable pool of glutamate and serotonin transporters densities are decreased in a few specific brain regions, mostly in the anterior cingulate in the patients. Although it is hypothesized that brain inflammation is involved in the pathophysiology of ME/CFS, there was no direct evidence of neuroinflammation in patients.

Our recent PET study successfully demonstrated that neuroinflammation is present in widespread brain areas in ME/CFS patients, and is associated with the severity of neuropsychological symptoms. Evaluation of neuroinflammation in patients with ME/CFS may be essential for understanding the core pathophysiology, as well as for developing objective diagnostic criteria and effective medical treatments for ME/CFS. By using specific neurological features of these patients such as prefrontal cortical atrophies and the over-guarding phenomenon were found using MRI and functional MRI, respectively. We here describe related pathophysiological findings and topics in order to aid in the development of future therapies for ME/CFS patients.

Source: Watanabe Y. Brain Science on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Brain Nerve. 2018 Nov;70(11):1193-1201. doi: 10.11477/mf.1416201164. [Article in Japanese]  https://www.ncbi.nlm.nih.gov/pubmed/30416112

Insights into myalgic encephalomyelitis/chronic fatigue syndrome phenotypes through comprehensive metabolomics

Abstract:

The pathogenesis of ME/CFS, a disease characterized by fatigue, cognitive dysfunction, sleep disturbances, orthostatic intolerance, fever, irritable bowel syndrome (IBS), and lymphadenopathy, is poorly understood.

We report biomarker discovery and topological analysis of plasma metabolomic, fecal bacterial metagenomic, and clinical data from 50 ME/CFS patients and 50 healthy controls. We confirm reports of altered plasma levels of choline, carnitine and complex lipid metabolites and demonstrate that patients with ME/CFS and IBS have increased plasma levels of ceramide.

Integration of fecal metagenomic and plasma metabolomic data resulted in a stronger predictive model of ME/CFS (cross-validated AUC = 0.836) than either metagenomic (cross-validated AUC = 0.745) or metabolomic (cross-validated AUC = 0.820) analysis alone. Our findings may provide insights into the pathogenesis of ME/CFS and its subtypes and suggest pathways for the development of diagnostic and therapeutic strategies.

Source: Dorottya Nagy-Szakal, Dinesh K. Barupal, Bohyun Lee, Xiaoyu Che, Brent L. Williams, Ellie J. R. Kahn, Joy E. Ukaigwe, Lucinda Bateman, Nancy G. Klimas, Anthony L. Komaroff, Susan Levine, Jose G. Montoya, Daniel L. Peterson, Bruce Levin, Mady Hornig, Oliver Fiehn & W. Ian Lipkin . Insights into myalgic encephalomyelitis/chronic fatigue syndrome phenotypes through comprehensive metabolomics. Scientific Reports, volume 8, Article number: 10056 (2018) https://www.nature.com/articles/s41598-018-28477-9 (Full article)