Kunihiro Sakuma

By Kotomi Sakai and Kunihiro Sakuma

Dysphagia (swallowing difficulties) is a serious problem associated with malnutrition, dehydration, aspiration pneumonia, and death. Its well‐known causes include stroke, neuromuscular disease, and head and neck cancer, and these affect muscles and sensation during deglutition. In recent years, dysphagia due to sarcopenia (i.e. “sarcopenic dysphagia”) has been reported as a new concept. Sarcopenic dysphagia results from low swallowing and general skeletal muscle mass and strength. The characteristic changes in swallowing muscles occur primarily in oral and pharyngeal muscles along with other associated factors. With a rapidly aging population, the number of older adults with sarcopenic dysphagia is expected to increase. Therefore, it is necessary to investigate the pathophysiology and treatment strategies for sarcopenic dysphagia. In this chapter, we summarize previous studies related to sarcopenic dysphagia.

Part of the book: Frailty and Sarcopenia

By Kunihiro Sakuma

Part of the book: Muscular Dystrophies

By Muneshige Shimizu and Kunihiro Sakuma

Muscle atrophy occurs under a number of different conditions, including disuse and aging accompanied by the onset of sarcopenia. Although muscle mass is reduced by decreased protein synthesis and/or increased protein degradation, the mechanisms of disuse muscle atrophy and sarcopenia differ. Therefore, nutrition strategies need to be customized for each type of muscle atrophy. Difficulties are associated with assessing the efficacy of nutrients for preventing sarcopenia due to uncontrolled factors in human studies. We herein (a) summarize nutritional epidemiology evidence related to sarcopenia from recent systematic reviews, (b) review nutrient supplementation for attenuating sarcopenia through dietary control, and (c) provide evidence for the efficacy of nutrient supplementation for treating disuse muscle atrophy under dietary control. Epidemiological studies have indicated that diets with a sufficient intake of beneficial foods are useful for preventing sarcopenia. Supplementation with vitamin D and leucine-enriched whey protein have been suggested to help attenuate sarcopenia in geriatric patients, particularly those who are unable to exercise. Further studies are needed to clarify the effects of protein and amino acid supplementation on muscle mass and strength. High-quality studies with controlled diets and physical activities are required to clarify the effects of nutritional interventions on both types of muscle atrophy.

Part of the book: Background and Management of Muscular Atrophy

By Nobuo Morotomi, Kunihiro Sakuma and Kotomi Sakai

In patients with heart failure (HF), it is important to perform exercise therapy with a focus on the pathophysiology of skeletal muscle. Patients with HF have multiple clinical symptoms due to cardiac dysfunction. Recent studies demonstrated the mechanism and treatment strategy for HF, and multiple signaling pathways involved in HF result in reduced exercise capacity and skeletal muscle mass. On the other hand, exercise therapy for HF is known to inhibit the inflammatory cytokines and neurohumoral factors, and increase muscle mass. Therefore, in this chapter, we discuss the importance of exercise therapy for HF, with a focus on the pathophysiology of skeletal muscle.

Part of the book: Muscle Cell and Tissue

By Muneshige Shimizu and Kunihiro Sakuma

Malnutrition caused by aging or disease can be defined as a state resulting from the lack of intake or uptake of nutrition, which leads to a change in body composition and the consequent impairment of physical and mental functions. Sarcopenia is a geriatric syndrome characterized by a progressive loss of skeletal muscle mass, strength, and performance. In this chapter, we (a) summarize the relationship between malnutrition and sarcopenia in various subjects, (b) review nutritional epidemiological evidence related to the prevention of sarcopenia, and (c) show evidence for the efficacy of nutrient supplementation in attenuating muscle atrophy in several patients. Malnutrition is closely related to severe sarcopenia, especially in older hospitalized adults, patients with chronic kidney disease (CKD), those undergoing hemodialysis, and those with cancer. Healthy diets (i.e., those ensuring a sufficient intake of beneficial foods, such as vegetables, fish, nuts, fruits, low-fat foods, and whole-grain products) are useful in preventing sarcopenia. The Mediterranean diet is a particularly healthy diet, but other diets, such as the healthy Nordic diet and traditional Asian diet, also help attenuate sarcopenia in older adults. Proteins, vitamins, minerals, and n-3 polyunsaturated fatty acids are important nutrients for patients with CKD, those on hemodialysis, and those with cancer.

Part of the book: Combating Malnutrition through Sustainable Approaches