Total body nitrogen as a predictor of clinical status in anorexia nervosa

Abstract

It has been demonstrated that clinical outcome is positively correlated with depletion of total body nitrogen (TBN) and therefore of body protein in certain serious medical conditions such as cystic fibrosis or patients receiving dialysis for chronic renal failure. Patients with anorexia nervosa are not suffering from medical illness per se yet the illness can be chronic and severely debilitating requiring numerous hospitalizations for refeeding and/or management of medical complications. The prediction of chronicity remains an important and difficult issue that this study seeks to address by examining the correlation between several clinical indices in 18 patients suffering from anorexia nervosa with parameters of body composition, namely TBN and percentage body fat. TBN was measured using the technique of in vivo neutron‐activation analysis (IVNAA) and expressed as nitrogen index. Percentage body fat was estimated using skinfold measurements. The highest correlation was between nitrogen index and number of hospitalizations (r = ‐.80). The data support a relationship between depletion of body nitrogen/protein and chronicity in anorexia nervosa. © 1994 by John Wiley & Sons, Inc.

Body composition in young female eating-disorder patients with severe weight loss and controls: evidence from the four-component model and evaluation of DXA

“…Previous studies describing body composition differences between AN patients and controls have been inconsistent. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 11 This inconsistency may be due in part to the use of different body composition methods. DXA has been used in several studies of ED patients; 2 , 5 , 37 however, these studies have not demonstrated the validity of DXA in ED patients using an accurate reference method.…”

“…Some studies found lower FFM in AN patients compared with controls, 2 , 3 , 4 , 5 , 6 whereas others reported no difference. 7 , 8 , 9 , 10 , 11 This inconsistency also applies to other diseases of malnutrition.…”

Body composition in young female eating-disorder patients with severe weight loss and controls: evidence from the four-component model and evaluation of DXA

“…Previous studies describing body composition differences between AN patients and controls have been inconsistent. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 11 This inconsistency may be due in part to the use of different body composition methods. DXA has been used in several studies of ED patients; 2 , 5 , 37 however, these studies have not demonstrated the validity of DXA in ED patients using an accurate reference method.…”

“…Some studies found lower FFM in AN patients compared with controls, 2 , 3 , 4 , 5 , 6 whereas others reported no difference. 7 , 8 , 9 , 10 , 11 This inconsistency also applies to other diseases of malnutrition.…”

Total Body Protein in Chronic Diseases and in Aging

“…Russell et al 7 demonstrated that TBN, expressed as the NI, was more strongly correlated with the number of hospitalizations in anorexia nervosa than any other clinical parameter studied. In a further study, this group concluded that TBN is a direct measure of protein recovery following refeeding and is unaffected by potassium and hydration status.…”

Anorexia nervosa and nutritional assessment: contribution of body composition measurements

“…SFT measurements have been frequently used in AN studies ( 39 ) . Measurements are less affected by the hydration status of the patient compared with other methods, which makes this technique advantageous in AN patients.…”

Body composition in young female eating-disorder patients with severe weight loss and controls: evidence from the four-component model and evaluation of DXA

“…Previous studies describing body composition differences between AN patients and controls have been inconsistent. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 11 This inconsistency may be due in part to the use of different body composition methods. DXA has been used in several studies of ED patients; 2 , 5 , 37 however, these studies have not demonstrated the validity of DXA in ED patients using an accurate reference method.…”

“…Some studies found lower FFM in AN patients compared with controls, 2 , 3 , 4 , 5 , 6 whereas others reported no difference. 7 , 8 , 9 , 10 , 11 This inconsistency also applies to other diseases of malnutrition.…”

Total Body Protein in Chronic Diseases and in Aging

“…Russell et al 7 demonstrated that TBN, expressed as the NI, was more strongly correlated with the number of hospitalizations in anorexia nervosa than any other clinical parameter studied. In a further study, this group concluded that TBN is a direct measure of protein recovery following refeeding and is unaffected by potassium and hydration status.…”

Anorexia nervosa and nutritional assessment: contribution of body composition measurements

“…SFT measurements have been frequently used in AN studies ( 39 ) . Measurements are less affected by the hydration status of the patient compared with other methods, which makes this technique advantageous in AN patients.…”

Body composition in young female eating-disorder patients with severe weight loss and controls: evidence from the four-component model and evaluation of DXA

“…Previous studies describing body composition differences between AN patients and controls have been inconsistent. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 11 This inconsistency may be due in part to the use of different body composition methods. DXA has been used in several studies of ED patients; 2 , 5 , 37 however, these studies have not demonstrated the validity of DXA in ED patients using an accurate reference method.…”

“…Some studies found lower FFM in AN patients compared with controls, 2 , 3 , 4 , 5 , 6 whereas others reported no difference. 7 , 8 , 9 , 10 , 11 This inconsistency also applies to other diseases of malnutrition.…”

Total Body Protein in Chronic Diseases and in Aging

“…Russell et al 7 demonstrated that TBN, expressed as the NI, was more strongly correlated with the number of hospitalizations in anorexia nervosa than any other clinical parameter studied. In a further study, this group concluded that TBN is a direct measure of protein recovery following refeeding and is unaffected by potassium and hydration status.…”

Anorexia nervosa and nutritional assessment: contribution of body composition measurements

“…SFT measurements have been frequently used in AN studies ( 39 ) . Measurements are less affected by the hydration status of the patient compared with other methods, which makes this technique advantageous in AN patients.…”