Diagnosis of denutrition in elderly patients using dual energy adsorptiometry

OBJECTIVES: Denutrition is a frequent condition in elderly persons and may have major consequences. A noninvasive investigation, whole body dual energ y X-ray adsorptiometry, should allow by direct measurement of body composit ion,early and reliable diagnosis of denutrition. This study was conducted t o elaborate a diagnostic tool using this exam and to lest its validity. PATIENTS AND METHODS: A global index of denutrition was proposed combining anthropometric, biological criteria, and the Mini Nutritional Assessment sc ale. Two agreement analyses were made between classical diagnostic criteria of nutritional status and body fat and fat free mass assessed by anthromom etry and adsorptiometry. An association between nutritional status and body adsorptiometric composition were studied with univariate analysis followed by a multivariate logistic regression model. This model allowed an elabora tion of a nutritional adsorptiometric index (NAI). RESULTS: One hundred one elderly subjects were included. Twenty-three were considered to be in a state of denutrition. Agreement was poor between anth ropometric and biological diagnostic cirteria of denutrition. It was good b etween the different masses assess by anthropometry and adsorptiometry. Sub jects in a state of denutrition had significantly lower body fat and lower fat free mass. The fat free mass index (fat free mass divided by the square height) and body fat were entered into a logistic model and composed the N AI, which showed good diagnostic validity in terms of specificity and sensi tivity. DISCUSSION: Adsorptiometry appears to be a simple reliable diagnostic tool for assessing denutrition in elderly persons in routine practice. Further s tudies are required and should lead to a confirmation of the interest of th ese absorptiometric indexes.