[Study of energy expenditure in anorexia nervosa: agreement between indirect calorimatry and several equations].
Nutritional management is essential in anorexia nervosa (AN), although nutrient replenishment must be done progressively to prevent the occurrence of re-alimentation syndrome.


OBJECTIVE
to compare resting enengy expenditure (REE) by means of indirect calorimetry and by different equations in AN female patients.


METHODS
we studied 21 women admitted for AN (DSM-IV), mean age 17 years (SD 5.9), range 12-34 years. Admission stay was 55.1 +/- 20.7 days (21-91). Initial nutritional assessment included anthropometrics (BMJ, TSF, SSE, MAC, MAMC) and tetrapolar bioimpedance (HoltainBC). Indirect calorimetry (IC) was done after overnight fasting (Deltatrac II MBM-200). In 9 patients, the same study was repeated before hospital discharge. We compared REE (Kcal/24 h) measured by IC with that obtained by several equations [Fleish, Harris- Benedict, FAO, Schofield-HW (SHW), Schebendach] through the intraclass correlation coefficient (ICC) and the Bland-Altman method.


RESULTS
Nutritional status significantly improved during hospital admission. Fifty percent of the recovered weight was fat mass. REE significantly increased during admission. The equations overestimated REE as compared to IC (p < 0.05), except for the Schebendach equation that underestimated REE. The agreement between direct measurement of REE by IC and its estimation through equations was poor [Fleish (ICC = 0.21); HB (ICC = 0.21), SHW (ICC = 0.19), Schebendach (ICC = 0.15)]. Through the Bland-Altman method, we observed that there was a variable bias between IC and equations, with a clinically acceptable agreement for REW values of around 1200 Kcal/day.


CONCLUSIONS
1) In our study we obtained a poor agreement between REW values measured by indirect calorimetry and those estimated by equations. 2) Through the Bland-Altman method, we observed that all equations present a variable bias as for IC, the agreement being clinically acceptable for REE values of around 1200 Kcal/day. 3) Thus, indirect calorimetry seems to be a very useful tool to calculate the energy requirements of anorexia nervosa patients.
Cuerda Compés
M C
MC
Unidad de Nutrición, Hospital General Universitario Gregorio Marañón. Madrid, España. mcuerda.hgugm@salud.madrid.org
Ruiz Sancho
A
A
Moreno Rengel
C
C
Iriondo Martínez
M T
MT
Velasco Gimeno
C
C
Bretón Lesmes
I
I
Camblor Alvarez
M
M
García Peris
P
P
D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000378:metabolism*; D002153:Calorimetry, Indirect; D002648:Child; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D011446:Prospective Studies; D012146:Rest