[Special aspects of malnutrition in geriatrics]

In 1992 people aged 65 years and over represented 11.9% (men) and 17.2% (women) of the Swiss population, and in 2000 the average 65-year-old man or woman can expect to live about 12 more years. Old age is characterized by multimorbidity, an accumulation of chronic conditions and diseases, and by social isolation. Multimorbidity and isolation (living alone) are the major risk factors for malnutrition. 30-60% of all persons aged 65 years and over show one or more subnormal nutritional parameters. The unspecific and oligosymptomatic clinical picture of malnutrition in the elderly often hinders an early diagnosis, and malnutrition is often misdiagnosed as "wasting away syndrome" of the old. Thus, the nutritional assessment of the elderly should become a routine diagnostic procedure. Detection of malnutrition involves assessment of nutritional parameters including history (eating habits, appetite), anthropometric measurements (weight, height, body mass index, triceps skinfold, midarm circumference), serum proteins (albumin, transferrin, prealbumin, cholinesterase, retinol binding protein), vitamins (B12, folic acid, B1, B2, B6, C and D), minerals and trace elements (zinc, magnesium, calcium, iron), immunologic skin tests and lymphocyte count. Depending on the history and the clinical symptoms, a selected number of these nutritional parameters are assessed. When assessing the nutritional status of the elderly it is important to define the etiologic factors involved. Thus, treatment of underlying causes and refeeding can be streamlined, so that maximum benefit can be obtained for the quality of life of the elderly.