@article{9a373516374a487ab0cb690f79948515,
title = "Long-COVID fatigue is not predicted by pre-pandemic plasma IL-6 levels in mild COVID-19",
abstract = "OBJECTIVE AND DESIGN: Fatigue is a prominent symptom in the general population and may follow viral infection, including SARS-CoV2 infection which causes COVID-19. Chronic fatigue lasting more than three months is the major symptom of the post-COVID syndrome (known colloquially as long-COVID). The mechanisms underlying long-COVID fatigue are unknown. We hypothesized that the development of long-COVID chronic fatigue is driven by the pro-inflammatory immune status of an individual prior to COVID-19.SUBJECTS AND METHODS: We analyzed pre-pandemic plasma levels of IL-6, which plays a key role in persistent fatigue, in N = 1274 community dwelling adults from TwinsUK. Subsequent COVID-19-positive and -negative participants were categorized based on SARS-CoV-2 antigen and antibody testing. Chronic fatigue was assessed using the Chalder Fatigue Scale.RESULTS: COVID-19-positive participants exhibited mild disease. Chronic fatigue was a prevalent symptom among this population and significantly higher in positive vs. negative participants (17% vs 11%, respectively; p = 0.001). The qualitative nature of chronic fatigue as determined by individual questionnaire responses was similar in positive and negative participants. Pre-pandemic plasma IL-6 levels were positively associated with chronic fatigue in negative, but not positive individuals. Raised BMI was associated with chronic fatigue in positive participants.CONCLUSIONS: Pre-existing increased IL-6 levels may contribute to chronic fatigue symptoms, but there was no increased risk in individuals with mild COVID-19 compared with uninfected individuals. Elevated BMI also increased the risk of chronic fatigue in mild COVID-19, consistent with previous reports.",
keywords = "Adult, Humans, Post-Acute COVID-19 Syndrome, COVID-19, Interleukin-6, Fatigue Syndrome, Chronic/epidemiology, Pandemics, RNA, Viral, SARS-CoV-2",
author = "Freidin, {Maxim B} and Nathan Cheetham and Duncan, {Emma L} and Steves, {Claire J} and Doores, {Katherine J} and Malim, {Michael H} and Niccolo Rossi and Lord, {Janet M} and Franks, {Paul W} and Alessandra Borsini and {Granville Smith}, Isabelle and Mario Falchi and Carmine Pariante and Williams, {Frances M K}",
note = "Funding Information: The study was supported by Kennedy Trust grant #KENN 19-20-10. JML is supported by the NIHR Birmingham Biomedical Research Centre, and CMP by the South London and Maudsley NHS Foundation Trust & King{\textquoteright}s College London Biomedical Research Centre; the views expressed here are those of the authors and not necessarily those of the NHS, NIHR or Department for Health and Social Care. Mario Falchi is supported by MRC grant MR/T004142/1. TwinsUK is funded by the Wellcome Trust, Medical Research Council, Versus Arthritis, European Union Horizon 2020, Chronic Disease Research Foundation (CDRF), Zoe Ltd and the National Institute for Health Research (NIHR) Clinical Research Network (CRN) and Biomedical Research Centre based at Guy{\textquoteright}s and St Thomas{\textquoteright} NHS Foundation Trust in partnership with King{\textquoteright}s College London. Funding Information: The study was supported by Kennedy Trust grant #KENN 19-20-10. JML is supported by the NIHR Birmingham Biomedical Research Centre, and CMP by the South London and Maudsley NHS Foundation Trust & King{\textquoteright}s College London Biomedical Research Centre; the views expressed here are those of the authors and not necessarily those of the NHS, NIHR or Department for Health and Social Care. Mario Falchi is supported by MRC grant MR/T004142/1. TwinsUK is funded by the Wellcome Trust, Medical Research Council, Versus Arthritis, European Union Horizon 2020, Chronic Disease Research Foundation (CDRF), Zoe Ltd and the National Institute for Health Research (NIHR) Clinical Research Network (CRN) and Biomedical Research Centre based at Guy{\textquoteright}s and St Thomas{\textquoteright} NHS Foundation Trust in partnership with King{\textquoteright}s College London. Publisher Copyright: {\textcopyright} 2023, The Author(s).",
year = "2023",
month = may,
doi = "10.1007/s00011-023-01722-2",
language = "English",
volume = "72",
pages = "947--953",
journal = "Inflammation Research",
issn = "1023-3830",
publisher = "Birkhauser Verlag Basel",
number = "5",
}