Physical activity and risk of infection, severity and mortality of COVID-19: a systematic review and non-linear dose–response meta-analysis of data from 1 853 610 adults
Yasmin Ezzatvar, Robinson Ramírez-Vélez, Mikel Izquierdo, Antonio Garcia-Hermoso
British Journal of Sports Medicine, doi:10.1136/bjsports-2022-105733
Objective To quantify the association between physical activity and risk of SARS-CoV-2 infection, COVID-19associated hospitalisation, severe illness and death due to COVID-19 in adults. Design A systematic review and meta-analysis. Data sources Three databases were systematically searched through March 2022. Eligibility criteria for selecting studies Peerreviewed articles reporting the association between regular physical activity and at least one COVID-19 outcome in adults were included. Risk estimates (ORs, relative risk (RR) ratios or HRs) were extracted and pooled using a random-effects inverse-variance model. Results Sixteen studies were included (n=1 853 610). Overall, those who engaged in regular physical activity had a lower risk of infection (RR=0.89; 95% CI 0.84 to 0.95; I 2 =0%), hospitalisation (RR=0.64; 95% CI 0.54 to 0.76; I 2 =48.01%), severe COVID-19 illness (RR=0.66; 95% CI 0.58 to 0.77; I 2 =50.93%) and COVID-19-related death (RR=0.57; 95% CI 0.46 to 0.71; I 2 =26.63%) as compared with their inactive peers. The results indicated a non-linear dose-response relationship between physical activity presented in metabolic equivalent of task (MET)-min per week and severe COVID-19 illness and death (p for non-linearity <0.001) with a flattening of the dose-response curve at around 500 MET-min per week. Conclusions Regular physical activity seems to be related to a lower likelihood of adverse COVID-19 outcomes. Our findings highlight the protective effects of engaging in sufficient physical activity as a public health strategy, with potential benefits to reduce the risk of severe COVID-19. Given the heterogeneity and risk of publication bias, further studies with standardised methodology and outcome reporting are now needed. PROSPERO registration number CRD42022313629. Contributors AG-H and YE conceptualised and designed the study, drafted the initial manuscript, and reviewed and revised the manuscript. RR-V and YE designed the data collection instruments, collected data, carried out the initial analyses and reviewed and revised the manuscript. MI and AG-H conceptualised and designed the study, coordinated and supervised data collection, and critically reviewed the manuscript for important intellectual content. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. AG-H is responsible for the integrity of the work as a whole.
Competing interests None declared. Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not applicable. Ethics approval Not applicable. Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise. Online supplemental eTable 2. Results Online supplemental eFigure 1. Doi plot for hospitalisation. Relative Risk was transferred to natural logarithm form. BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)
References
Ahmadi, Huang, Inan-Eroglu, Lifestyle risk factors and infectious disease mortality, including COVID-19, among middle aged and older adults: evidence from a community-based cohort study in the United Kingdom, Brain Behav Immun,
doi:10.1016/j.bbi.2021.04.022Brandenburg, Lesser, Thomson, Does higher self-reported cardiorespiratory fitness reduce the odds of hospitalization from COVID-19?, J Phys Act Health,
doi:10.1123/jpah.2020-0817Brandenburg, Lesser, Thomson, Giles, Does higher self-reported cardiorespiratory fitness reduce the odds of hospitalization from COVID-19?, J Phys Act Heal,
doi:10.1123/jpah.2020-0817Brandenburg, Lesser, Thomson, Giles, Does higher self-reported cardiorespiratory fitness reduce the odds of hospitalization from COVID-19?, J Phys Act Heal,
doi:10.1123/jpah.2020-0817Chastin, Abaraogu, Bourgois, Effects of regular physical activity on the immune system, vaccination and risk of community-acquired infectious disease in the general population: systematic review and meta-analysis, Sports Med,
doi:10.1007/s40279-021-01466-1Cho, Lee, Physical activity and the risk of covid-19 infection and mortality: a nationwide population-based case-control study, J Clin Med,
doi:10.3390/jcm10071539Christensen, Arneja, Cyr, Sturrock, Brooks, The association of estimated cardiorespiratory fitness with COVID-19 incidence and mortality: A cohort study, PLoS One,
doi:10.1371/journal.pone.0250508Christensen, Arneja, Cyr, Sturrock, Brooks, The association of estimated cardiorespiratory fitness with COVID-19 incidence and mortality: A cohort study, PLoS One,
doi:10.1371/journal.pone.0250508Christensen, Arneja, Cyr, The association of estimated cardiorespiratory fitness with COVID-19 incidence and mortality: a cohort study, PLoS One,
doi:10.1371/journal.pone.0250508Cunningham, Physical activity and its relationship with COVID-19 cases and deaths: analysis of U.S. counties, J Sport Health Sci,
doi:10.1016/j.jshs.2021.03.008De Souza, Motta-Santos, Soares, Association of physical activity levels and the prevalence of COVID-19-associated hospitalization, J Sci Med Sport,
doi:10.1016/j.jsams.2021.05.011Duggal, Niemiro, Harridge, Can physical activity ameliorate immunosenescence and thereby reduce age-related multi-morbidity?, Nat Rev Immunol,
doi:10.1038/s41577-019-0177-9Dwyer, Pasini, Dominicis, Physical activity: benefits and challenges during the COVID-19 pandemic, Scand J Med Sci Sports,
doi:10.1111/sms.13710Ekblom-Bak, Väisänen, Ekblom, Cardiorespiratory fitness and lifestyle on severe COVID-19 risk in 279,455 adults: a case control study, Int J Behav Nutr Phys Act,
doi:10.1186/s12966-021-01198-5Fierens, Goossens, Exercise versus no exercise for the occurrence, severity and duration of acute respiratory infections, Int J Nurs Pract,
doi:10.1111/ijn.12891Furuya-Kanamori, Barendregt, Doi, A new improved graphical and quantitative method for detecting bias in meta-analysis, Int J Evid Based Healthc,
doi:10.1097/XEB.0000000000000141Geijerstam, Mehlig, Börjesson, Fitness, strength and severity of COVID-19: a prospective register study of 1 559 187 Swedish conscripts, BMJ Open,
doi:10.1136/bmjopen-2021-051316Greenland, Model-based estimation of relative risks and other epidemiologic measures in studies of common outcomes and in case-control studies, Am J Epidemiol,
doi:10.1093/aje/kwh221Gualano, Fitness, strength and severity of COVID-19: A prospective register study of 1 559 187 Swedish conscripts, Br J Sports Med,
doi:10.1136/bjsports-2022-105426Hallam, Jones, Alley, Exercise after influenza or COVID-19 vaccination increases serum antibody without an increase in side effects, Brain Behav Immun,
doi:10.1016/j.bbi.2022.02.005Hamdan, Badrasawi, Zidan, Risk factors associated with hospitalization owing to COVID-19: a cross-sectional study in palestine, J Int Med Res,
doi:10.1177/03000605211064405Hamer, 'donovan, Stamatakis, Lifestyle risk factors, obesity and infectious disease mortality in the general population: linkage study of 97,844 adults from England and Scotland, Prev Med,
doi:10.1016/j.ypmed.2019.03.002Hamer, Kivimäki, Gale, Lifestyle risk factors, inflammatory mechanisms, and COVID-19 hospitalization: a community-based cohort study of 387,109 adults in UK, Brain Behav Immun,
doi:10.1016/j.bbi.2020.05.059Hamling, Lee, Weitkunat, Facilitating meta-analyses by deriving relative effect and precision estimates for alternative comparisons from a set of estimates presented by exposure level or disease category, Stat Med,
doi:10.1002/sim.3013Hamrouni, Roberts, Thackray, Associations of obesity, physical activity level, inflammation and cardiometabolic health with COVID-19 mortality: A prospective analysis of the UK Biobank cohort, BMJ Open,
doi:10.1136/bmjopen-2021-055003Hamrouni, Roberts, Thackray, Associations of obesity, physical activity level, inflammation and cardiometabolic health with COVID-19 mortality: A prospective analysis of the UK Biobank cohort, BMJ Open,
doi:10.1136/bmjopen-2021-055003Hamrouni, Roberts, Thackray, Associations of obesity, physical activity level, inflammation and cardiometabolic health with COVID-19 mortality: a prospective analysis of the UK biobank cohort, BMJ Open,
doi:10.1136/bmjopen-2021-055003Heart, Undefined, Health, and BI. Quality assessment tool for observational cohort and cross-sectional studies
Inthout, Ioannidis, Borm, The hartung-knapp-sidik-jonkman method for random effects meta-analysis is straightforward and considerably outperforms the standard derSimonian-laird method, BMC Med Res Methodol,
doi:10.1186/1471-2288-14-25Jeong, Kim, Kang, Mortality reduction with physical activity in patients with and without cardiovascular disease, Eur Heart J,
doi:10.1093/eurheartj/ehz564Latorre-Román, Ángel, Guzmán-Guzmán, Delgado-Floody, Protective role of physical activity patterns prior to COVID-19 confinement with the severity/ duration of respiratory pathologies consistent with COVID-19 symptoms in Spanish populations, Res Sports Med,
doi:10.1080/15438627.2021.1937166Leandro, Ferreira, Silva, Ae, Covid-19 and exercise-induced immunomodulation, Neuroimmunomodulation,
doi:10.1159/000508951Lee, Lee, Moon, Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study, Br J Sports Med,
doi:10.1136/bjsports-2021-104203Localio, Margolis, Berlin, Relative risks and confidence intervals were easily computed indirectly from multivariable logistic regression, J Clin Epidemiol,
doi:10.1016/j.jclinepi.2006.12.001Maltagliati, Sieber, Sarrazin, Muscle strength explains the protective effect of physical activity against COVID-19 hospitalization among adults aged 50 years and older, J Sports Sci,
doi:10.1080/02640414.2021.1964721Maltagliati, Sieber, Sarrazin, Muscle strength explains the protective effect of physical activity against COVID-19 hospitalization among adults aged 50 years and older, J Sports Sci,
doi:10.1080/02640414.2021Maltagliati, Sieber, Sarrazin, Muscle strength explains the protective effect of physical activity against COVID-19 hospitalization among adults aged 50 years and older, J Sports Sci,
doi:10.1080/02640414.2021Mcnutt, Wu, Xue, Estimating the relative risk in cohort studies and clinical trials of common outcomes, Am J Epidemiol,
doi:10.1093/aje/kwg074Mehlig, Börjesson, Online supplemental emethod 2. Excluded studies and reasons for exclusion. Did not include physical activity data: Af Geijerstam A, BMJ Open,
doi:10.1136/bmjopen-2021-051316Nieman, Henson, Austin, Upper respiratory tract infection is reduced in physically fit and active adults, Br J Sports Med,
doi:10.1136/bjsm.2010.077875Orsini, Li, Wolk, Meta-analysis for linear and nonlinear dose-response relations: examples, an evaluation of approximations, and software, Am J Epidemiol,
doi:10.1093/aje/kwr265Page, Mckenzie, Bossuyt, The PRISMA 2020 statement: an updated guideline for reporting systematic reviews, BMJ,
doi:10.1136/bmj.n71Pinto, Goessler, Fernandes, No independent associations between physical activity and clinical outcomes among hospitalized patients with moderate to severe COVID-19, J Sport Heal Sci,
doi:10.1016/j.jshs.2021.08.001Pinto, Goessler, Fernandes, No independent associations between physical activity and clinical outcomes among hospitalized patients with moderate to severe COVID-19, J Sport Heal Sci,
doi:10.1016/j.jshs.2021.08.001Richardson, Hirsch, Narasimhan, Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area, JAMA,
doi:10.1001/jama.2020.6775Rothman, Greenland, Lash, Modern epidemiology
Rowlands, Dempsey, Gillies, Association between accelerometerassessed physical activity and severity of COVID-19 in UK biobank, Mayo Clin Proc Innov Qual Outcomes,
doi:10.1016/j.mayocpiqo.2021.08.011Salgado-Aranda, Pérez-Castellano, Núñez-Gil, Influence of Baseline Physical Activity as a Modifying Factor on COVID-19 Mortality: A Single-Center, Retrospective Study, Infect Dis Ther,
doi:10.1007/s40121-021-00418-6Salgado-Aranda, Pérez-Castellano, Núñez-Gil, Influence of Baseline Physical Activity as a Modifying Factor on COVID-19 Mortality: A Single-Center, Retrospective Study, Infect Dis Ther,
doi:10.1007/s40121-021-00418-6Sallis, Young, Tartof, Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48 440 adult patients, Br J Sports Med,
doi:10.1136/bjsports-2021-104080Sellami, Gasmi, Denham, Effects of acute and chronic exercise on immunological parameters in the elderly aged: can physical activity counteract the effects of aging?, Front Immunol,
doi:10.3389/fimmu.2018.02187Senna, Torres, Lopes, Moderate physical training attenuates perinatal low-protein-induced spleen lymphocyte apoptosis in endotoxemic adult offspring rats, Eur J Nutr,
doi:10.1007/s00394-015-0925-ySteenkamp, Saggers, Bandini, Small steps, strong shield: directly measured, moderate physical activity in 65 361 adults is associated with significant protective effects from severe COVID-19 outcomes, Br J Sports Med,
doi:10.1136/bjsports-2021-105159Stroup, Berlin, Morton, Meta-analysis of observational studies in epidemiology: a proposal for reporting, J Am Med Assoc,
doi:10.1001/jama.283.15.2008Tavakol, Ghannadi, Tabesh, Relationship between physical activity, healthy lifestyle and COVID-19 disease severity; a cross-sectional study, J Public Health,
doi:10.1007/s10389-020-01468-9Zhang, Kf, What's the relative risk? a method of correcting the odds ratio in cohort studies of common outcomes, J Am Med Assoc,
doi:10.1001/jama.280.19.1690Zhang, Li, Sun, Physical activity and COVID-19: an observational and Mendelian randomisation study, J Glob Health,
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'aging?',
'volume': '9',
'author': 'Sellami',
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