Association between sarcopenia and pneumonia in older people

Pneumonia is a major cause of death in older people, and the number of such deaths is increasing. Present guidelines for pneumonia management are based on a pathogen-oriented strategy that relies on the optimal application of antibiotics. Older pneumonia inpatients show the high incidence of aspiration pneumonia. The main cause of aspiration pneumonia is an impairment in the swallowing and cough reflexes. These facts suggest a limitation of present management strategies and a requirement for new strategies for aspiration pneumonia. Sarcopenia is the loss of muscle strength and mass, and declining physical function with aging. Recently, a decrease in the mass or strength of the swallowing muscles was suggested to be associated with reduced swallowing function. Accordingly, dysphagia caused by sarcopenia of the systemic and swallowing-related muscles was named sarcopenic dysphagia. Presently, few studies have shown associations between aspiration pneumonia and sarcopenic dysphagia. As for the cough reflex, strong cough prevents aspiration pneumonia, and its strength is regulated by respiratory muscles. A few studies have reported a relationship between muscles and pneumonia in older people. Sarcopenia is a risk factor for pneumonia in older people, and aspiration pneumonia inpatients with low muscle mass show high mortality rates. Aspiration pneumonia induced muscle atrophy in respiratory, swallowing, and skeletal muscles in an animal model and humans. Associations between respiratory muscle strength and pneumonia are currently under investigation. Evaluation and management of sarcopenia could potentially become a new strategy to prevent and treat pneumonia in older patients, and research has only recently been launched. Geriatr Gerontol Int 2020; 20: 7-13.