Osteosarcopenia and Long-COVID: a dangerous combination

Abstract

SARS-CoV-2 has caused a global pandemic and an unprecedented public health crisis, infecting more than 580 million people worldwide. Moreover, recent evidence has suggested the emergence of a new syndrome known as Long-COVID, a term used to describe a diverse set of physical and mental symptoms that persist after a diagnosed SARS-CoV-2 infection. Epidemiological data have identified myalgias, muscle and joint dysfunction, and bone fragility as common sequelae in patients with moderate and severe forms of this disease. Significant musculoskeletal dysfunction has also been detected in some healed patients, although knowledge about pathophysiological mechanisms of Long-COVID is still rather scarce. In this context, SARS-CoV-2 infection has been suggested to amplify the effects of aging on the musculoskeletal system by aggravating the osteosarcopenic state. Based on this evidence, our review focused on the muscle and bone tissue alterations induced by SARS-CoV-2 infection and Long-COVID, summarizing the current knowledge on the underlying biological mechanisms and highlighting the need for a multidisciplinary approach to predict the musculoskeletal targets and long-term consequences of COVID-19 disease.

Keywords: Aging; Long-COVID; SARS-CoV-2 infection; musculoskeletal system; osteosarcopenia.

Figure 1.

SARS-CoV-2 infection is responsible for severe acute inflammation, triggering a storm of cytokines and inducing multi-organ damage. The musculoskeletal system is also one of the target tissues infected by the virus. The ACE2 expression in muscle and bone cells could promotes virus binding, causing myalgia, weakness, and injury in muscles, and demineralization and fragility in bones.

Figure 2.

The interaction between COVID-19 and osteosarcopenia could be bidirectional and trigger a vicious circle. Indeed, factors associated with SARS-CoV-2 infection, such as social isolation, sedentariness and malnutrition, are known to promote osteosarcopenia. Conversely, events triggering osteosarcopenia, such as inflammatory reaction and metabolic dysfunction, are also factors associated with COVID-19 disease.