The interconnection between Covid-19, sarcopenia and lifestyle

In March 2020, Covid-19 was declared a global pandemic by the World Health Organization. Infection with Sars-Cov-2, the virus responsible for Covid-19, can have a wide range of consequences, the severity of which depends on the individual [[1]Guerrina R. Borisch B. Callahan L.F. Howick J. Reginster J.Y. Mobasheri A. Health and gender inequalities of the COVID-19 pandemic: adverse impacts on women's health, wealth and social welfare.Front Glob Womens Health. 2021; 2670310Crossref PubMed Scopus (7) Google Scholar]. Moreover, this vulnerability is increased by the presence of comorbidities such as chronic respiratory disease, diabetes, hypertension and other pathologies affecting immunity [[2]Gold M.S. Sehayek D. Gabrielli S. Zhang X. McCusker C. Ben-Shoshan M. COVID-19 and comorbidities: a systematic review and meta-analysis.Postgrad. Med. 2020; 132: 749-755Crossref PubMed Scopus (154) Google Scholar]. Also, musculoskeletal disorders, and particularly sarcopenia, have recently been suggested to be either a consequence of [[3]Kirwan R. McCullough D. Butler T. Perez de Heredia F. Davies I.G. Stewart C. Sarcopenia during COVID-19 lockdown restrictions: long-term health effects of short-term muscle loss.Geroscience. 2020; 42: 1547-1578Crossref PubMed Scopus (152) Google Scholar] or a risk factor for [[4]Siahaan Y.M.T. Hartoyo V. Hariyanto T.I. Kurniawan A. Coronavirus disease 2019 (Covid-19) outcomes in patients with sarcopenia: A meta-analysis and meta-regression.Clin Nutr ESPEN. 2022; 48: 158-166Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar] Covid-19. For example, studies have reported muscle damage in patients hospitalized for Covid-19 and greater loss of muscle function in older women living independently during the pandemic [5Mao L. Jin H. Wang M. Hu Y. Chen S. He Q. Chang J. Hong C. Zhou Y. Wang D. Miao X. Li Y. Hu B. Neurologic manifestations of hospitalized patients with coronavirus disease 2019 in WuhanChina.JAMA Neurol. 2020; 77: 683-690Crossref PubMed Scopus (4402) Google Scholar, 6Visser M. Schaap L.A. Wijnhoven H.A.H. Self-reported impact of the COVID-19 pandemic on nutrition and physical activity behaviour in dutch older adults living independently.Nutrients. 2020; 12Crossref Scopus (98) Google Scholar]. Some studies, but not all, have also highlighted that low skeletal muscle mass and reduced muscle strength are associated with higher severity of Covid-19 [7Ma Y. He M. Hou L.S. Xu S. Huang Z.X. Zhao N. Kang Y. Yue J.R. Wu C. The role of SARC-F scale in predicting progression risk of COVID-19 in elderly patients: a prospective cohort study in Wuhan.BMC Geriatr. 2021; 21: 355Crossref PubMed Scopus (11) Google Scholar, 8Yi X. Liu H. Zhu L. Wang D. Xie F. Shi L. Mei J. Jiang X. Zeng Q. Hu P. Li Y. Pang P. Liu J. Peng W. Bai H.X. Liao W. Chen B.T. Myosteatosis predicting risk of transition to severe COVID-19 infection.Clin. Nutr. 2021; (Epub ahead of print)https://doi.org/10.1016/j.clnu.2021.05.031Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar, 9Lengele L. Locquet M. Moutschen M. Beaudart C. Kaux J.F. Gillain S. Reginster J.Y. Bruyere O. Frailty but not sarcopenia nor malnutrition increases the risk of developing COVID-19 in older community-dwelling adults.Aging Clin. Exp. Res. 2022; 34: 223-234Crossref PubMed Scopus (8) Google Scholar]. Very recently, histopathological changes in muscle, such as muscle atrophy, have also been identified in patients complaining of long-term Covid-19 symptoms, including fatigue and weakness [[10]Hejbol E.K. Harbo T. Agergaard J. Madsen L.B. Pedersen T.H. Ostergaard L.J. Andersen H. Schroder H.D. Tankisi H. Myopathy as a cause of fatigue in long-term post-COVID-19 symptoms: evidence of skeletal muscle histopathology.Eur. J. Neurol. 2022; 29: 2832-2841Crossref PubMed Scopus (19) Google Scholar]. In addition, results from a meta-analysis highlighted a twofold greater risk of getting severe complications and of mortality due to Covid-19 for sarcopenic people compared with non-sarcopenic ones [[4]Siahaan Y.M.T. Hartoyo V. Hariyanto T.I. Kurniawan A. Coronavirus disease 2019 (Covid-19) outcomes in patients with sarcopenia: A meta-analysis and meta-regression.Clin Nutr ESPEN. 2022; 48: 158-166Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar]. Three potentially modifiable factors appear to be associated with both sarcopenia and Covid-19 and can be considered a target for prevention: high level of systemic inflammation, low levels of physical activity and poor nutrition:-High level of systemic inflammation: Sarcopenia can potentially induce a higher level of inflammation, which can be observed with trough biomarkers such as interleukin-15 (IL-15), interleukin-6 (IL-6) and C-reactive protein (CRP) [11Nelke C. Dziewas R. Minnerup J. Meuth S.G. Ruck T. Skeletal muscle as potential central link between sarcopenia and immune senescence.EBioMedicine. 2019; 49: 381-388Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar, 12Bano G. Trevisan C. Carraro S. Solmi M. Luchini C. Stubbs B. Manzato E. Sergi G. Veronese N. Inflammation and sarcopenia: a systematic review and meta-analysis.Maturitas. 2017; 96: 10-15Abstract Full Text Full Text PDF PubMed Scopus (367) Google Scholar]. In parallel, in severe forms of Covid-19 disease, a high level of biomarkers of inflammation (i.e. IL-6 and IL-10) have been found [[13]Dhar S.K. K V. Damodar S. Gujar S. Das M. IL-6 and IL-10 as predictors of disease severity in COVID-19 patients: results from meta-analysis and regression.Heliyon. 2021; 7e06155Abstract Full Text Full Text PDF PubMed Scopus (87) Google Scholar] and can potentially increase the risk of acute sarcopenia [[14]Piotrowicz K. Gasowski J. Michel J.P. Veronese N. Post-COVID-19 acute sarcopenia: physiopathology and management.Aging Clin. Exp. Res. 2021; 33: 2887-2898Crossref PubMed Scopus (84) Google Scholar].-Low physical activity: The model of “catabolic crisis”, which proposes that sarcopenia is not only like a progressive process but also aggravated by acute periods of inactivity, was meaningful during the Covid-19 crisis [[15]English K.L. Paddon-Jones D. Protecting muscle mass and function in older adults during bed rest.Curr. Opin. Clin. Nutr. Metab. Care. 2010; 13: 34-39Crossref PubMed Scopus (321) Google Scholar]. Indeed, quarantine, lockdown restriction and hospitalization were among the many conditions that affected lifestyle behaviours and consequently might have increased the risk of developing sarcopenia. In this context, a systematic review showed an overall global trend of decreased physical activity in older adults due to lockdown restrictions [[16]Elisabeth A.L. Karlen S.B. Magkos F. The effect of COVID-19-related lockdowns on diet and physical activity in older adults: a systematic review.Aging Dis. 2021; 12: 1935-1947Crossref PubMed Scopus (32) Google Scholar]. The authors of this review noted that in addition to induced lower muscle mass and strength, which is directly associated with sarcopenia, lower levels of physical activity can lead to other non-communicable diseases that increase vulnerability to Covid-19 [[16]Elisabeth A.L. Karlen S.B. Magkos F. The effect of COVID-19-related lockdowns on diet and physical activity in older adults: a systematic review.Aging Dis. 2021; 12: 1935-1947Crossref PubMed Scopus (32) Google Scholar].-Poor nutrition: Some harmful eating behaviours have been reported during Covid-19 quarantine, such as skipping warm meals, eating less than normal and having less appetite [[6]Visser M. Schaap L.A. Wijnhoven H.A.H. Self-reported impact of the COVID-19 pandemic on nutrition and physical activity behaviour in dutch older adults living independently.Nutrients. 2020; 12Crossref Scopus (98) Google Scholar]. The impact of these changes was partially highlighted in a study in which 25 % of 1407 patients hospitalized for Covid-19 had significant weight loss before hospitalization [[17]Wierdsma N.J. Kruizenga H.M. Konings L.A. Krebbers D. Jorissen J.R. Joosten M.I. van Aken L.H. Tan F.M. van Bodegraven A.A. Soeters M.R. Weijs P.J. Poor nutritional status, risk of sarcopenia and nutrition related complaints are prevalent in COVID-19 patients during and after hospital admission.Clin. Nutr. ESPEN. 2021; 43: 369-376Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar]. In that study, this malnourishment could be partly explained by Covid-19-related symptoms like ageusia, change of taste, nausea, vomiting, and anorexia [[17]Wierdsma N.J. Kruizenga H.M. Konings L.A. Krebbers D. Jorissen J.R. Joosten M.I. van Aken L.H. Tan F.M. van Bodegraven A.A. Soeters M.R. Weijs P.J. Poor nutritional status, risk of sarcopenia and nutrition related complaints are prevalent in COVID-19 patients during and after hospital admission.Clin. Nutr. ESPEN. 2021; 43: 369-376Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar]. Those changes in eating habits may cause a decrease in protein intake. Indeed, insufficient intake can lead to a reduction in muscle protein synthesis which is an aggravating factor for sarcopenia [[3]Kirwan R. McCullough D. Butler T. Perez de Heredia F. Davies I.G. Stewart C. Sarcopenia during COVID-19 lockdown restrictions: long-term health effects of short-term muscle loss.Geroscience. 2020; 42: 1547-1578Crossref PubMed Scopus (152) Google Scholar]. In addition, the decrease in physical activity observed during the pandemic could indirectly lead to changes in other lifestyle behaviours, including those related to nutrition. Indeed, during the Covid-19 pandemic, people with lower physical activity levels increased snacking habits and alcohol consumption [[6]Visser M. Schaap L.A. Wijnhoven H.A.H. Self-reported impact of the COVID-19 pandemic on nutrition and physical activity behaviour in dutch older adults living independently.Nutrients. 2020; 12Crossref Scopus (98) Google Scholar]. These eating habits may lead to overnutrition, as discussed in a Brazilian study conducted in older women during the pandemic that revealed an increase of body mass index and body weight but also an increased risk of sarcopenia [[18]da Rocha A.Q. Lobo P.C.B. Pimentel G.D. Muscle function loss and gain of body weight during the COVID-19 pandemic in elderly women: effects of one year of lockdown.J. Nutr. Health Aging. 2021; 25: 1028-1029Crossref PubMed Scopus (14) Google Scholar]. The good news, at least for preventive actions for both Covid-19 and sarcopenia, is that inflammation, physical activity and nutrition are all potentially modifiable and interconnected factors. As specified by the International Clinical Practice Guidelines for Sarcopenia, physical activity and adapted diet are crucial in the management of sarcopenia [[19]Dent E. Morley J.E. Cruz-Jentoft A.J. Arai H. Kritchevsky S.B. Guralnik J. Bauer J.M. Pahor M. Clark B.C. Cesari M. Ruiz J. Sieber C.C. Aubertin-Leheudre M. Waters D.L. Visvanathan R. Landi F. Villareal D.T. Fielding R. Won C.W. Theou O. Martin F.C. Dong B. Woo J. Flicker L. Ferrucci L. Merchant R.A. Cao L. Cederholm T. Ribeiro S.M.L. Rodriguez-Manas L. Anker S.D. Lundy J. Gutierrez Robledo L.M. Bautmans I. Aprahamian I. Schols J. Izquierdo M. Vellas B. International clinical practice guidelines for sarcopenia (ICFSR): screening, diagnosis and management.J. Nutr. Health Aging. 2018; 22: 1148-1161Crossref PubMed Scopus (425) Google Scholar]. For physical activity, to date, resistance-based training is still preferred for its benefits for muscle strength, physical performance and muscle hypertrophy [[19]Dent E. Morley J.E. Cruz-Jentoft A.J. Arai H. Kritchevsky S.B. Guralnik J. Bauer J.M. Pahor M. Clark B.C. Cesari M. Ruiz J. Sieber C.C. Aubertin-Leheudre M. Waters D.L. Visvanathan R. Landi F. Villareal D.T. Fielding R. Won C.W. Theou O. Martin F.C. Dong B. Woo J. Flicker L. Ferrucci L. Merchant R.A. Cao L. Cederholm T. Ribeiro S.M.L. Rodriguez-Manas L. Anker S.D. Lundy J. Gutierrez Robledo L.M. Bautmans I. Aprahamian I. Schols J. Izquierdo M. Vellas B. International clinical practice guidelines for sarcopenia (ICFSR): screening, diagnosis and management.J. Nutr. Health Aging. 2018; 22: 1148-1161Crossref PubMed Scopus (425) Google Scholar]. Regarding nutrition, it is recommended that older adults are monitored to ensure energy balance as well as adequate intake of protein and vitamin D. Acting on these two together can generate a decrease in inflammation and further potentially reduce the risk of sarcopenia. Indeed, in their systematic review, Bautmans et al. have highlighted a substantial lower level of inflammatory markers such as IL-6 and CRP in older adults following a physical exercise program in comparison with those who have not [[20]Bautmans I. Salimans L. Njemini R. Beyer I. Lieten S. Liberman K. The effects of exercise interventions on the inflammatory profile of older adults: a systematic review of the recent literature.Exp. Gerontol. 2021; 146111236Crossref PubMed Scopus (25) Google Scholar]. In addition, a recent meta-analysis highlighted that healthy eating behaviours such as high intake of fresh fruits are correlated with lower level of inflammatory biomarkers [[21]Norde M.M. Collese T.S. Giovannucci E. Rogero M.M. A posteriori dietary patterns and their association with systemic low-grade inflammation in adults: a systematic review and meta-analysis.Nutr. Rev. 2021; 79: 331-350Crossref PubMed Scopus (15) Google Scholar]. In conclusion, even though most restrictive rules have been lifted in almost all countries, Covid-19 is still active. On 15 August 2022, for one year 375 million new cases and over 2 million deaths were reported on a global scale [[22]W.H. OrganizationCOVID-19 Weekly Epidemiological Update.2022Google Scholar]. At present, older populations are still considered vulnerable to Covid-19. Sarcopenia appears to be a risk factor for as well as a consequence of Covid-19 and has repercussions in terms of severity and mortality. In line with what some authors have called “a wake-up call for lifestyle-related preventable conditions in older adults” [[23]Lim M.A. Smith L. COVID-19 pandemic: a wake-up call for lifestyle-related preventable conditions in older adults.Aging Clin. Exp. Res. 2021; 33: 2367-2368Crossref PubMed Scopus (2) Google Scholar], public health authorities and health professionals [[24]Altin Z. Buran F. Attitudes of health professionals toward elderly patients during the COVID-19 pandemic.Aging Clin. Exp. Res. 2022; (Epub ahead of print): 1-10https://doi.org/10.1007/s40520-022-02209-6Crossref PubMed Scopus (1) Google Scholar] should be aware of the connection between sarcopenia and Covid-19 and the factors aiming at reducing their burden. Céline Demonceau participated in data collection and analysis, and in drafting and editing of the paper. Charlotte Beaudart participated in data collection and analysis, and in drafting and editing of the paper. Jean-Yves Reginster participated in data collection and analysis. Nicola Veronese participated in data collection and analysis. Oliver Bruyère participated in data collection and analysis, and in drafting and editing of the paper. All authors saw and approved the final version and no other person made a substantial contribution to the paper. The authors received no funding from an external source for the preparation of this editorial.