[Aging-related frailty and sarcopenia. Frailty, sarcopenia and dysphagia.]

Frailty and sarcopenia occur not only in whole-body but also oral and swallowing function. Presbyphagia is age-related decline of swallowing function in older adults. Oral frailty is age-related decline of oral function in older adults. Presbyphagia and oral frailty are not dysphagia but frailty of oral and swallowing function. Oral sarcopenia is defined as sarcopenia in muscles of the oral cavity. Sarcopenic dysphagia is characterized by swallowing difficulty resulting from a loss of mass and function in whole-body skeletal and swallowing muscles. Sarcopenic dysphagia is diagnosed using a 5-step algorithm for sarcopenic dysphagia. Iatrogenic sarcopenia can be one of the causes of sarcopenic dysphagia. Iatrogenic sarcopenia is defined as sarcopenia caused by the activities of medical staff including doctors, nurses, or other health care professionals in healthcare facilities. Iatrogenic sarcopenia has three categories:1)activity-related:caused by unnecessary inactivity or unnecessary nil per os, 2)nutrition-related:caused by inappropriate nutritional care management, and 3)disease-related:in case of iatrogenic diseases. Rehabilitation nutrition is recommended for preventing and treating sarcopenic dysphagia. Rehabilitation nutrition is defined as that which 1)evaluates holistically by the International Classification of Functioning, Disability and Health, and the presence and cause of nutritional disorders, sarcopenia, and excess or deficiency of nutritional intake;2)conducts rehabilitation nutrition diagnosis and rehabilitation nutrition goal setting;and 3)elicits the highest body functions, activities, participations, and quality of life by improving nutritional status, sarcopenia, and frailty using 'nutrition care management in consideration of rehabilitation' and 'rehabilitation in consideration of nutrition' in people with a disability and frail older people. Rehabilitation nutrition can be practiced by using the rehabilitation nutrition care process, which is a systematic problem-solving method. It consists of five steps:rehabilitation nutrition assessment and diagnostic reasoning, rehabilitation nutrition diagnosis, rehabilitation nutrition goal setting, rehabilitation nutrition intervention, and rehabilitation nutrition monitoring.