Alteration in nutritional status and diaphragm muscle function.

Diet-induced undernutrition causes deleterious changes in the structure and function of the diaphragm muscle. Diseases associated with somatic washing cause atrophy of the respiratory muscles. In cachectic subjects, the diaphragm muscle mass and thickness are reduced in proportion to the reduction in body weight. In addition, respiratory muscle strength and endurance are reduced more dramatically than the weight loss. This finding suggests that malnutrition induces a reduction in muscular mass which is associated with a decrease in contractility. Diaphragmatic weakness may increase the risk of respiratory failure in patients with chronic obstructive pulmonary disease (COPD). The primary goal of a successful nutritional programme is to improve the diaphragm strength by correcting the mineral, electrolyte and energetic disturbances at the muscular level, the latter being responsible for the decreased contractability associated with malnutrition.