Association of sarcopenia with the long-term risk of overall infections and infectious diseases: a prospective cohort study of 458 332 participants.

Sarcopenia, characterized by the progressive loss of muscle strength and mass, is a condition linked to increased frailty and mortality. However, its role in heightening the susceptibility to infections and infectious diseases remains unclear. This study aimed to investigate the long-term associations between sarcopenia and the risk of overall infections and infectious diseases using data from a large prospective cohort of 465 592 adults. Participants were categorized into three groups: non-sarcopenia, probable sarcopenia, and confirmed sarcopenia. Over a median follow-up of 12.5 years, compared with participants without sarcopenia, those with probable sarcopenia had a hazard ratio (HR) of 1.18 (95% confidence interval (CI) 1.15-1.21), and those with confirmed sarcopenia had an HR of 1.34 (95% CI 1.21-1.48) for developing infections or infectious diseases. The study also found that handgrip strength and muscle mass were independently associated with an increased risk of infections. These findings indicate that sarcopenia and low muscle strength are important markers of increased infection risk in the general population and highlight the need for further research, particularly in younger adults with low muscle strength, to determine whether interventions to improve muscle strength and mass can reduce infection risk.