Poster Topical Area: Energy and Macronutrient Metabolism
Location: Hall D
Poster Board Number: 465
Objectives: To compare predictive equations (PE) with indirect calorimetry (IC) to estimate basal energy expenditure (BEE) in patients in the late postoperative of bariatric surgery.
Methods: An observational cross-sectional study, where adult individuals (18 to 60 years old) of both sexes were included, who underwent bariatric surgery, 2 to 7 years ago, by Roux en-Y gastric bypass. Measured BEE was obtained by IC (Invoice Vmax29) after 8 hours of fasting for 30 minutes. The estimated BEE was obtained using the PE of Harris & Benedict (HB), Schofield, FAO/WHO/UNU (WHO), Mifflin-St Jeor and Orozco-Ruiz. Body composition was assessed by dual energy X-ray absorptiometry (Lunnar, DPX-IQ). Underestimation and overestimation were considered when estimated BEE exceeded the value measured by IC by ±10%. The agreement of PE were evaluated through the intraclass correlation coefficient, with a 95% confidence interval. Pearson's correlation was applied to investigate association between the mean error of the PE and anthropometric and body composition variables.
Results: Twenty-two participants (38.4±6.4 years old; 86.4% women; 29.9±4.5kg/m²) were enrolled in this analysis with a postoperative time of 3.8 years (2.6, 5.3) The measured BEE mean value of 1479±149kcal, was significantly lower than PE by HB (1606±239kcal, p=0.001), Schofield (1571±232kcal, p=0.006), WHO (1595±233kcal, p=0.001) and Orozco-Ruiz (1606±247kcal, p=0.001), except for Mifflin-St Jeor equation (1514±227kcal, p=0.26). However, the mean overestimation of PE compared to IC was 8.5% for HB, 6.1% for Schofield, 7.7% for WHO and 8.4% for Orozco-Ruiz, all considered acceptable. The Mifflin-St Jeor equation presented the best agreement (r=0.84, 0.62-0.93) to the value measured by IC. Positive associations between all means of PE errors with BMI (r=0.65, p=0.001) and fat mass (r=0.73, p<0.001) were observed.
Conclusions: Although all the equations tested showed acceptable comparison to IC, Mifflin-St Jeor presented the best results to estimate BEE in long-term bariatric patients. The PE errors associations suggested that the greater the mass and body fat, the greater disagreements of the results, which may compromise the results in severe obese individuals.
Postgraduate Program in Human Nutrition, University of Brasília (PPGNH/UnB) and Undergraduate Nutrition Course, University Center Unieuro (UNIEURO). Brasília, Federal District, Brazil
Rio De Janeiro, Rio de Janeiro, Brazil