BODY-COMPOSITION BY X-RAY ABSORPTIOMETRY AND BIOELECTRICAL-IMPEDANCE IN CHRONIC RESPIRATORY INSUFFICIENCY PATIENTS

Nutrition assessment is important during chronic respiratory insuffici ency to evaluate the level of malnutrition or obesity and should inclu de body composition measurements. The appreciation of fat-free and fat reserves in patients with chronic respiratory insufficiency can aid i n designing an adapted nutritional support, e.g., nutritional support in malnutrition and food restriction in obesity. The purpose of the pr esent study was to cross-validate fat-free and Eat mass obtained by va rious bioelectric impedance (BIA) formulas with the fat-free and fat m ass measured by dual-energy X-ray absorptiometry (DXA) and determine t he formulas that are best suited to predict the fat-free and fat mass for a group of patients with severe chronic respiratory insufficiency. Seventy-five patients (15 women and 60 men) with chronic obstructive and restrictive respiratory insufficiency aged 45-86 y were included i n this study. Body composition was calculated according to 13 differen t BIA formulas fur women and 12 for men and compared with DXA. Because of the variability, calculated as 2 standard deviations, of +/-5.0 kg fat-free mass for women and +/-6.4 kg for men for the best predictive formula, the use of the various existing BIA formulas was considered not clinically relevant. Therefore disease-specific formulas for patie nts with chronic respiratory insufficiency should be developed to impr ove the prediction of fat-free and fat mass by BIA in these patients. (C) Elsevier Science Inc. 1997.