Low Weight and Nutritional Deficiency

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To the Editor:—The article by Mowé and Bøhmer1 and the accompanying editorial by Morley2 in the November issue of the Journal of the American Geriatric Society include examples of the major dilemmas in understanding low weight and nutritional deficiency in elderly people. In the article by Mowé and Bøhmer, weight less than 90% of “ideal” was considered to define “malnutrition” per IDC-9 criteria. Using this definition, respiratory disease and neoplasms were observed to be associated with malnutrition, and heart disease was observed to be significantly not associated with malnutrition. The difficulty is in determining cause and effect. Malnutrition is a cause of weight loss, to be sure; not so are neoplasms and respiratory disease. Obesity is associated with prevalence of heart disease; but heart disease, especially heart failure, causes weight gain. Disease and weight loss (along with other manifestations of malnutrition) are intimately linked. Malnutrition as a cause of weight loss can only be diagnosed if nutritional supplementation reverses the weight loss. It is a mistake to call the weight loss of neoplasia or respiratory disease “malnutrition” unless it is reversed by nutrition. What is needed are controlled prospective, but cross-sectional, studies of people with weight loss, such as that of Kaiser et al,3 with careful measurement of food intake and control of disease processes. Without such studies, clinicians who treat weight loss as if it was all “malnutrition” risk treating diseases such as cancer or tuberculosis with nutritional supplements alone. Although the mnemonics proposed have educational importance, the editorial by Morley2 adds to the difficulty in diagnosing malnutrition because it suggests (1) that malnutrition can be diagnosed without testing the effects of nutrition and (2) that the negative acute phase measurements, plasma cholesterol and albumin levels, may be diagnostic of malnutrition. Moreover, it makes unsupported recommendations for parenteral nutritional support. As noted above in the comments about weight loss, diagnosis of malnutrition by weight, anthropometry, or other measurement made at a single point in time may be misleading since the importance of diseases which should be diagnosed and treated may be underemphasized. As noted by Kaiser et al,3 some elderly people with low weight may have growth hormone deficiency. To treat growth hormone deficient patients (or patients with diabetes or thyroid hormone abnormalities) with nutrition alone would be a mistake. Secondly, many studies have shown that, although albumin and cholesterol levels are decreased in patients with diseases and poor food intake, disease burden may be more important than malnutrition in causing low albumin and cholesterol levels. Finally, a recent study of parenteral nutrition in hospitalized patients4 showed minimal benefit. In consideration of the high cost and morbidity associated with parenteral feeding on the integrity of the intestinal mucosa, aggressive enteral feeding should be used for nutritional supplementation except in cases of short bowel syndrome, total bowel obstruction, or intractable malabsorption. Parenteral nutrition should not be used prophylactially to prevent malnutrition caused by diagnostic tests or canceled surgical procedures. Such iatrogenesis should be prevented by education and appropriate patient care. Editor's note:—The above letter was referred to the authors of the original articles. Dr. Morley's reply follows.