Bidirectional Relationships Between COVID-19 and Frailty in Older Adults

At the start of the pandemic, it became evident that older adults were most likely to develop severe COVID-19 infection when exposed to the SARS-CoV-2 virus. Although chronological age is important, male sex, common chronic diseases, and residence in a long-term care facility emerged as additional key risk factors. As frailty began to be considered in this context, it became evident that individuals with prevalent or incident frailty after COVID-19 infection were particularly vulnerable. COVID-19 infection also appears to accelerate the risk and progression of declines in physical performance, sarcopenia, and frailty, highlighting the bidirectional relationships between frailty and this infection. COVID-19 mRNA vaccines appear to be quite effective even in frail older adults, which represents one means to prevent acceleration of frailty. Beyond public health measures like COVID-19 vaccination, it remains to be seen to what extent physical activity, exercise, and nutritional interventions may offer additional protection from severe COVID-19 infection or may overcome worsening physical function and frailty in infected individuals. In this chapter, we discuss the bidirectional relationship between COVID-19 infection and frailty, and offer insight into measures that may limit the impact these comorbidities have on each other.