[Diagnosing malnutrition in the elderly].

The concept of malnutrition in the geriatric population describes a deficient state of energy and nutrient intake with harmful clinical consequences. Despite of having a significant effect on morbidity and mortality, there are no generally accepted criteria for diagnosing malnutrition in the elderly. With increasing age the general recognition of the nutritional status becomes more important for the diagnosis of malnutrition than isolated parameters. Recording a patient"s history must include any weight loss and changes in appetite. Reasons for a diminished nutritional intake must be explored systematically as well. As part of physical examination one has to pay attention to clinical signs of malnutrition (general muscular atrophy, loss of subcutaneous fat) and to signs of micronutrient deficiencies. The documentation of oral intake can supply important evidence for deficient intake of energy and nutrients. Of special relevance among anthropometric values are a BMI of less than 20 kg/m and calf circumference of less than 31 cm. Individual follow-up data are superior to isolated measurements Laboratory diagnostic tests (for example albumin) are of minor importance for the diagnosis of malnutrition because of their low specificity. As a consequence of unsolved methodical problems, bioelectrical impedance analysis can currently be recommended only to those who are experienced with this method and its limitations. Screening and assessment tools like Mini Nutritional Assessment (MNA) and Nutritional Risk Screening(NRS) are helpful for a quick and simple identification of malnourished patients and those who are at risk. The MNA is especially applicable for people who live independently and for cooperative residents of nursing homes. The NRS is a valuable alternative for hospital patients and those unable to cooperate. Screening for malnutrition should be routine practice in the elderly population, especially for those at high risk for it like in hospitals and in nursing homes.