Long COVID in the Older Adult and Vitamin D

Abstract:

Background: The coronavirus COVID-19 strain that emerged in December 2019 continues to produce a widespread and seemingly intractable negative impact on health and longevity and life quality in all parts of the world, especially, among older adults with chronic health conditions.

Objectives: The first aim of this updated review article was to examine, summarize, synthesize, and report on the research base concerning the possible use of vitamin D in the realm of the recently emergent syndrome termed long or post-acute COVID-19 disease. A second was to establish any health associated preventive and intervention recommendations for the older adult with long COVID-19 manifestations, who may yet be susceptible to future COVID-19 variant infections and others.

Methods: To examine the association between vitamin D and long COVID-19 illness manifestations, articles responding to several key words entered into leading data bases were examined: These included the terms: Vitamin D, Long/Post-Acute COVID-19 and/or COVID-19. Databases employed were PUBMED, PubMed Central and Google Scholar. All relevant articles were carefully examined and those meeting the review criteria were carefully read, and described in narrative form.

Results: Data reveal some possible benefits may accrue in the context of COVID-19 illness prevention and rehabilitation by efforts to ensure optimal vitamin D serum levels among high risk, vitamin D deficient, and chronically challenged post-acute COVID-19 older adults.

Conclusion: More rigorous and carefully construed research efforts to examine vitamin D implications and its moderating or mediating role in averting or mitigating long COVID-19 health complications are strongly warranted.

Source: Ray Marks (2023) Long COVID in the Older Adult and Vitamin D. J Gerontol Geriatr Med 9: 155. https://www.heraldopenaccess.us/openaccess/long-covid-in-the-older-adult-and-vitamin-d (Full text)

The Role of Immunity and Inflammation in ME/ CFS and Post-COVID Syndrome: Implications for Treatment

Abstract:

Probably one in seven patients who have experienced acute COVID-19 continue having long-lasting complaints, called post-COVID syndrome or long-COVID, that are similar to those observed in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

There are good reasons to believe that common immunological, epigenetic and inflammatory mechanisms are involved in the pathogenesis both diseases.

To date, various therapeutic approaches have been recommended, but with moderate success. In the present opinion paper, the author weights his clinical experience against data from the literature, and suggests novel approaches.

In addition to general measures and paramedical approaches, food supplementation with a specific nutraceutical can be completed by oral administration of sodium dichloroacetate and Meldonium to optimize glucose metabolism and mitochondrial energy generation.

Alternatively, intravenous infusions with magnesium salt and multivitamins can be completed with glutathione, m-tranexamic acid, and cultured stem cells.

Preliminary results of an open-label, prospective, two-centre trial suggest more than four in five patients benefit from combined oral and infusion therapy with significantly diminished fatigue and improved well-being.

Monoclonal antibodies in “biologicals”, blocking the effects of cytokines, and “small molecules” with Janus kinase inhibiting activity may offer novel opportunities by focusing on both immunologic and inflammation targets. A pilot trial with, in particular, one of the Janus kinase inhibitors could be considered.

Source: Comhaire F. The Role of Immunity and Inflammation in ME/CFS and Post-COVID Syndrome: Implications for Treatment. MedLife Clinics 2022, Volume 4 (2), Article 1043 http://www.medtextpublications.com/open-access/the-role-of-immunity-and-inflammation-in-me-cfs-and-1254.pdf (Full text)

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Abstract:

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis.

A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence.

Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03).

The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p < 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Source: Tosato M, Calvani R, Picca A, Ciciarello F, Galluzzo V, Coelho-Júnior HJ, Di Giorgio A, Di Mario C, Gervasoni J, Gremese E, Leone PM, Nesci A, Paglionico AM, Santoliquido A, Santoro L, Santucci L, Tolusso B, Urbani A, Marini F, Marzetti E, Landi F; Gemelli against COVID-19 Post-Acute Care Team. Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial. Nutrients. 2022 Nov 23;14(23):4984. doi: 10.3390/nu14234984. PMID: 36501014; PMCID: PMC9738241. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9738241/ (Full text)

Polyphenols as possible alternative agents in chronic fatigue: a review

Abstract:

Chronic fatigue syndrome (CFS) is a pathological state of extreme tiredness that lasts more than six months and may possess an impact on the social, emotional, or occupational functioning of an individual. CFS is characterized by profound disabling fatigue associated with infectious, rheumatological, and neurological symptoms.

The current pharmacological treatment for CFS does not offer a complete cure for the disease, and none of the available treatments show promising results.

The exact mechanism of the pathogenesis of the disease is still unknown, with current suggestions indicating the overlapping roles of the immune system, central nervous system, and neuroendocrine system.

However, the pathological mechanism revolves around inflammatory and oxidative stress markers.

Polyphenols are the most abundant secondary metabolites of plant origin, with potent antioxidant and anti-inflammatory effects, and can exert protective activity against a whole range of disorders.

The current review is aimed at highlighting the emerging role of polyphenols in CFS from both preclinical and clinical studies. Numerous agents of this class have shown promising results in different in vitro and in vivo models of chronic fatigue/CFS, predominantly by counteracting oxidative stress and the inflammatory cascade.

The clinical data in this regard is still very limited and needs expanding through randomized, placebo-controlled studies to draw final conclusions on whether polyphenols may be a class of clinically effective nutraceuticals in patients with CFS.

Source: Ullah, H., Khan, A., Riccioni, C. et al. Polyphenols as possible alternative agents in chronic fatigue: a review. Phytochem Rev (2022). https://doi.org/10.1007/s11101-022-09838-9 (Full text)

Fatigue in Covid-19 survivors: The potential impact of a nutritional supplement on muscle strength and function

Summary:

Background: Fatigue with reduced tolerance to exercise is a common persistent long-lasting feature amongst COVID-19 survivors. The assessment of muscle function in this category of patients is often neglected.

Aim: To evaluate the potential impact of a daily supplementation based on amino acids, minerals, vitamins, and plant extracts (Apportal®) on muscle function, body composition, laboratory parameters and self-rated health in a small group of COVID-19 survivors affected by fatigue.

Methods: Thirty participants were enrolled among patients affected by physical fatigue during or after acute COVID-19 and admitted to the post-COVID-19 outpatient service at Fondazione Policlinico Gemelli in Rome between 1st March 2021 and 30th April 2021. All participants were evaluated at first visit (t0) and at control visit (t1), after taking a daily sachet of Apportal® for 28 days. Muscle function was analyzed using hand grip strength test, exhaustion strength time and the number of repetitions at one-minute chair stand test. Body composition was assessed with bioelectrical impedance analysis (BIA). Laboratory parameters, including standard blood biochemistry and ferritin levels, were evaluated at the first visit and during the control visit. A quick evaluation of self-rated health, before COVID-19, at t0 and t1, was obtained through a visual analogue scale (VAS).

Results: Participants aged 60 years and older were 13 (43%). Females represented the 70% of the study sample. Participants hospitalized for COVID-19 with low-flow oxygen supplementation represented the 43.3% of the study sample while 3.3% received noninvasive ventilation (NIV) or invasive ventilation. Hand grip strength improved from 26.3 Kg to 28.9 Kg (p < 0.05) at t1 as compared to t0. The mean time of strength exhaustion increased from 31.7 s (sec) at t0 to 47.5 s at t1 (p < 0.05). Participants performed a higher number of repetitions (28.3 vs. 22.0; p < 0.05) during the one-minute chair stand test at t1 as compared to t0. A trend, although not significant, in reduction of ferritin levels was found after nutritional supplementation (94.4 vs. 84.3, respectively; p = 0.01). The self-rated health status increased by at least 13 points (t0, mean 57.6 ± 5.86; t1, mean 71.4 ± 6.73; p < 0.05).

Conclusion: After 28 days of nutritional supplementation with Apportal® in COVID-19 survivors affected by fatigue with reduced tolerance to exercise, we found a significant improvement in means of muscle strength and physical performance, associated with enhancement of self-rated health status between t0 and t1.

Source: Vincenzo Galluzzo, Maria Beatrice Zazzara, Francesca Ciciarello, Giulia Savera, Cristina Pais, Riccardo Calvani, Anna Picca, Emanuele Marzetti, Francesco Landi, Matteo Tosato, Steering Committee, Francesco Landi, Elisa Gremese, Coordination, Roberto Bernabei, Massimo Fantoni, Antonio Gasbarrini, Field investigators, Gastroenterology team, Serena Porcari, Carlo Romano Settanni, Geriatric team, Francesca Benvenuto, Giulia Bramato, Vincenzo Brandi, Angelo Carfì, Francesca Ciciarello, Sofia Fabrizi, Vincenzo Galluzzo, Maria Rita Lo Monaco, Anna Maria Martone, Emanuele Marzetti, Carmen Napolitano, Francesco Cosimo Pagano, Cristina Pais, Sara Rocchi, Elisabetta Rota, Andrea Salerno, Matteo Tosato, Marcello Tritto, Maria Beatrice Zazzara, Riccardo Calvani, Lucio Catalano, Anna Picca, Giulia Savera, Francesco Paolo Damiano, Alessandra Rocconi, Alessandro Galliani, Giovanni Spaziani, Salvatore Tupputi, Camilla Cocchi, Flavia Pirone, Federica D’Ignazio, Stefano Cacciatore, Infectious disease team, Roberto Cauda, Enrica Tamburrini, A. Borghetti, Simona Di Gianbenedetto, Rita Murri, Antonella Cingolani, Giulio Ventura, E. Taddei, D. Moschese, A. Ciccullo, A. Dusina, Internal Medicine team, Leonardo Stella, Giovanni Addolorato, Francesco Franceschi, Gertrude Mingrone, M.A. Zocco, Microbiology team, Maurizio Sanguinetti, Paola Cattani, Simona Marchetti, Brunella Posteraro, M. Sali, Neurology team, Alessandra Bizzarro, Alessandra Lauria, Ophthalmology team, Stanislao Rizzo, Maria Cristina Savastano, G. Gambini, G.M. Cozzupoli, C. Culiersi, Otolaryngology team, Giulio Cesare Passali, Gaetano Paludetti, Jacopo Galli, F. Crudo, G. Di Cintio, Y. Longobardi, L. Tricarico, M. Santantonio, Pediatric team, Danilo Buonsenso, P. Valentini, D. Pata, D. Sinatti, C. De Rose, Pneumology team, Luca Richeldi, Francesco Lombardi, A. Calabrese, Paolo Maria Leone, Maria Rosaria Calvello, Enrica Intini, Giuliano Montemurro, Psychiatric team, Gabriele Sani, Delfina Janiri, Alessio Simonetti, G. Giuseppin, M. Molinaro, M. odica, Radiology team, Luigi Natale, Anna Rita Larici, Riccardo Marano, Rheumatology team, Annamaria Paglionico, Luca Petricca, Luca Gigante, G. Natalello, A.L. Fedele, M.M. Lizzio, B. Tolusso, Clara Di Mario, S. Alivernini, Vascular team, Angelo Santoliquido, Luca Santoro, Angela Di Giorgio, Antonio Nesci, V. Popolla, Fatigue in Covid-19 survivors: The potential impact of a nutritional supplement on muscle strength and function, Clinical Nutrition ESPEN, 2022, ISSN 2405-4577, https://doi.org/10.1016/j.clnesp.2022.08.029. (Full text)

Coenzyme Q10 + alpha lipoic acid for chronic COVID syndrome

Abstract:

Chronic COVID syndrome is characterized by chronic fatigue, myalgia, depression and sleep disturbances, similar to chronic fatigue syndrome (CFS) and fibromyalgia syndrome. Implementations of mitochondrial nutrients (MNs) with diet are important for the clinical effects antioxidant. We examined if use of an association of coenzyme Q10 and alpha lipoic acid (Requpero®) could reduce chronic covid symptoms.

The Requpero study is a prospective observational study in which 174 patients, who had developed chronic-covid syndrome, were divided in two groups: The first one (116 patients) received coenzyme Q10 + alpha lipoic acid, and the second one (58 patients) did not receive any treatment. Primary outcome was reduction in Fatigue Severity Scale (FSS) in treatment group compared with control group. complete FSS response was reached most frequently in treatment group than in control group. A FSS complete response was reached in 62 (53.5%) patients in treatment group and in two (3.5%) patients in control group. A reduction in FSS core < 20% from baseline at T1 (non-response) was observed in 11 patients in the treatment group (9.5%) and in 15 patients in the control group (25.9%) (p < 0.0001).

To date, this is the first study that tests the efficacy of coenzyme Q10 and alpha lipoic acid in chronic Covid syndrome. Primary and secondary outcomes were met. These results have to be confirmed through a double blind placebo controlled trial of longer duration.

Source: Barletta MA, Marino G, Spagnolo B, Bianchi FP, Falappone PCF, Spagnolo L, Gatti P. Coenzyme Q10 + alpha lipoic acid for chronic COVID syndrome. Clin Exp Med. 2022 Aug 22. doi: 10.1007/s10238-022-00871-8. Epub ahead of print. PMID: 35994177.  https://link.springer.com/article/10.1007/s10238-022-00871-8 (Full text)

The Use of Palmitoylethanolamide in the Treatment of Long COVID: A Real-Life Retrospective Cohort Study

COVID-19 can cause symptoms that last weeks or months after the infection has gone, with a significant impairment of quality of life. Palmitoylethanolamide (PEA) is a naturally occurring lipid mediator that has an entourage effect on the endocannabinoid system mitigating the cytokine storm. The aim of this retrospective study is to evaluate the potential efficacy of PEA in the treatment of long COVID.
Patients attending the Neurological Out Clinic of the IRCCS Centro Neurolesi Bonino-Pulejo (Messina, Italy) from August 2020 to September 2021 were screened for potential inclusion in the study. We included only long COVID patients who were treated with PEA 600 mg two times daily for about 3 months. All patients performed the post-COVID-19 Functional Status (PCFS) scale. Thirty-three patients (10 males, 43.5%, mean age 47.8 ± 12.4) were enrolled in the study. Patients were divided into two groups based on hospitalization or home care observation. A substantial difference in the PCFS score between the two groups at baseline and after treatment with PEA were found. We found that smoking was a risk factor with an odds ratio of 8.13 CI 95% [0.233, 1.167]. Our findings encourage the use of PEA as a potentially effective therapy in patients with long COVID.
Source: Raciti L, De Luca R, Raciti G, Arcadi FA, Calabrò RS. The Use of Palmitoylethanolamide in the Treatment of Long COVID: A Real-Life Retrospective Cohort Study. Medical Sciences. 2022; 10(3):37. https://doi.org/10.3390/medsci10030037  https://www.mdpi.com/2076-3271/10/3/37/htm (Full text)

Dietary supplements, daily nutrient intake, and health-related quality of life among people with myalgic encephalomyelitis/chronic fatigue syndrome

There remains ambiguity surrounding the role of dietary supplementation and nutrient intake on the health status of myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) patients, yet supplement use and dietary modification appear to be common among people with the condition. This pilot cross-sectional study aimed to investigate if supplement use or nutrient intake was associated with self-reported health-related quality of life (HRQoL) scores among Australians with ME/CFS.

The eligibility criteria for this study included being a resident of Australia, being aged between 18 and 65 years, and having received a formal diagnosis of ME/CFS from a physician. Participants completed a series of self-administered questionnaires querying sociodemographic information, symptom presentation, HRQoL, routine supplement use, and nutrient intake. The 36-item Short-Form Health Survey version 2 (SF-36) was employed to assess participants’ HRQoL. Daily nutrient intake was estimated from participants’ responses to the Dietary Questionnaire for Epidemiological Studies (Cancer Council Victoria, Australia). Multiple linear regression analysis was performed for each of the eight SF-36 domains. Age, gender, body mass index, employment, education were controlled variables in each model, with supplement and nutrient variables entered in a stepwise manner.

Twenty-four Australians with ME/CFS, 54.2% of which met the International Consensus Criteria case definition for ME/CFS, participated in the study. Three of the eight regression models were statistically significant, being the ‘role limitations due to physical health problems’ (adjusted R 2 = 0.733, P < 0.001), ‘bodily pain’ (adjusted R 2 = 0.544, P = 0.004), and ‘general health perceptions’ (adjusted R 2 = 0.743, P < 0.001) SF-36 domains. Positive associations were observed between HRQoL and the routine use of vitamin C (ß = 0.300, P = 0.042) and herbal supplements (ß = 0.618, P < 0.001), as well as daily saturated fat (ß = 0.860, P < 0.001), total folate (ß = 0.710, P < 0.001), and calcium intake (ß = 0.897, P = 0.003). However, the routine use of evening primrose oil supplements (ß = -0.385, P = 0.006) and daily intakes of alpha-linolenic acid (ß = −0.543, P = 0.001), long chain omega-3 fatty acids (ß = −0.431, P = 0.017), and iodine (ß = −0.602, P = 0.034) were negatively associated with HRQoL scores. None of the supplements or nutrients studied had consistent associations with HRQoL across the three significant regression models.

The findings of this pilot study suggest that there may be links between dietary supplementation and nutrient intake with HRQoL among people with ME/CFS. Future studies should investigate supplement use, daily nutrient intake, and their relationships with HRQoL and symptom presentation among people with ME/CFS longitudinally and compared with healthy controls to further elucidate the role of supplements and nutrient intake in the management of ME/CFS.

Read the full study HERE.

Source: Weigel, B., Eaton-Fitch, N., Passmore, R., Cabanas, H., Staines, D., & Marshall-Gradisnik, S. (2022). Dietary supplements, daily nutrient intake, and health-related quality of life among people with myalgic encephalomyelitis/chronic fatigue syndrome. Proceedings of the Nutrition Society, 81(OCE3), E80. doi:10.1017/S0029665122001057 https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/dietary-supplements-daily-nutrient-intake-and-healthrelated-quality-of-life-among-people-with-myalgic-encephalomyelitischronic-fatigue-syndrome/F837EC4FE783FFAEB44F66F7748C11F6 (Full text)

Could the kynurenine pathway be the key missing piece of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) complex puzzle?

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex and debilitating disease with a substantial social and economic impact on individuals and their community. Despite its importance and deteriorating impact, progresses in diagnosis and treatment of ME/CFS is limited. This is due to the unclear pathophysiology of the disease and consequently lack of prognostic biomarkers.

To investigate pathophysiology of ME/CFS, several potential pathologic hallmarks have been investigated; however, these studies have failed to report a consistent result. These failures in introducing the underlying reason for ME/CFS have stimulated considering other possible contributing mechanisms such as tryptophan (TRP) metabolism and in particular kynurenine pathway (KP).

KP plays a central role in cellular energy production through the production of nicotinamide adenine dinucleotide (NADH). In addition, this pathway has been shown to mediate immune response and neuroinflammation through its metabolites. This review, we will discuss the pathology and management of ME/CFS and provide evidence pertaining KP abnormalities and symptoms that are classic characteristics of ME/CFS. Targeting the KP regulation may provide innovative approaches to the management of ME/CFS.

Source: Kavyani B, Lidbury BA, Schloeffel R, Fisher PR, Missailidis D, Annesley SJ, Dehhaghi M, Heng B, Guillemin GJ. Could the kynurenine pathway be the key missing piece of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) complex puzzle? Cell Mol Life Sci. 2022 Jul 11;79(8):412. doi: 10.1007/s00018-022-04380-5. PMID: 35821534. https://link.springer.com/article/10.1007/s00018-022-04380-5  (Full text)

Oxaloacetate Treatment For Mental And Physical Fatigue In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long-COVID fatigue patients: a non-randomized controlled clinical trial

Abstract:

Background: There is no approved pharmaceutical intervention for Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS). Fatigue in these patients can last for decades. Long COVID may continue to ME/CFS, and currently, it is estimated that up to 20 million Americans have significant symptoms after COVID, and the most common symptom is fatigue. Anhydrous Enol-Oxaloacetate, (AEO) a nutritional supplement, has been anecdotally reported to relieve physical and mental fatigue and is diminished in ME/CFS patients. Here, we examine the use of higher dosage AEO as a medical food to relieve pathological fatigue.

Methods: ME/CFS and Long-COVID patients were enrolled in an open label dose escalating “Proof of Concept” non-randomized controlled clinical trial with 500 mg AEO capsules. Control was provided by a historical ME/CFS fatigue trial and supporting meta-analysis study, which showed average improvement with oral placebo using the Chalder Scale of 5.9% improvement from baseline. At baseline, 73.7% of the ME/CFS patients were women, average age was 47 and length of ME/CFS from diagnosis was 8.9 years. The Long-COVID patients were a random group that responded to social media advertising (Face Book) with symptoms for at least 6 months. ME/CFS patients were given separate doses of 500 mg BID (N = 23), 1,000 mg BID (N = 29) and 1000 mg TID (N = 24) AEO for six weeks. Long COVID patients were given 500 mg AEO BID (N = 22) and 1000 mg AEO (N = 21), again over a six-week period. The main outcome measure was to compare baseline scoring with results at 6 weeks with the Chalder Fatigue Score (Likert Scoring) versus historical placebo. The hypothesis being tested was formulated prior to data collection.

Results: 76 ME/CFS patients (73.7% women, median age of 47) showed an average reduction in fatigue at 6 weeks as measured by the “Chalder Fatigue Questionnaire” of 22.5% to 27.9% from baseline (P < 0.005) (Likert scoring). Both physical and mental fatigue were significantly improved over baseline and historical placebo. Fatigue amelioration in ME/CFS patients increased in a dose dependent manner from 21.7% for 500 mg BID to 27.6% for 1000 mg Oxaloacetate BID to 33.3% for 1000 mg TID. Long COVID patients’ fatigue was significantly reduced by up to 46.8% in 6-weeks.

Conclusions: Significant reductions in physical and metal fatigue for ME/CFS and Long-COVID patients were seen after 6 weeks of treatment. As there has been little progress in providing fatigue relief for the millions of ME/CFS and Long COVID patients, anhydrous enol oxaloacetate may bridge this important medical need. Further study of oxaloacetate supplementation for the treatment of ME/CFS and Long COVID is warranted.

Source: Cash, A., Kaufman, D.L. Oxaloacetate Treatment For Mental And Physical Fatigue In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long-COVID fatigue patients: a non-randomized controlled clinical trial. J Transl Med 20, 295 (2022). https://doi.org/10.1186/s12967-022-03488-3  https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03488-3 (Full text)