Usefulness of Baltasar's expected body mass index as an indicator of bariatric weight loss surgery.

Abstract

Determining the best indicator to report weight loss takes on special relevance following bariatric surgery. Our objective is to apply a method proposed by Baltasar et al. to express weight loss results following bariatric surgery. Anthropometric data were collected from 265 patients who had undergone Sleeve gastrectomy (SG, n = 172) and Roux-en-Y gastric bypass (RYGBP, n = 93) with a 2-year follow-up period. Initial BMI was calculated as well as BMI 2years after, percentage of excess BMI loss (PEBMIL), expected BMI (EBMI), and corrected PEBMIL. In SG group, average BMI 2years after surgery fell within a 95% CI of expected BMI, with an average BMI of 31.58 ± 4.05kg/m2 in 35-45 BMI group, an average BMI of 33.62 ± 4.96kg/m2 in 45-55 BMI group, and an average BMI of 37.40 ± 5.93kg/m2 in 55-65 BMI group. In RYGBP group, average BMI 2years after the surgery was below than average expected BMI (28.76 ± 3.20kg/m2 in 35-45 BMI group and 29.71 ± 3.30kg/m2 in 45-55 BMI group). Results are considered excellent for the group with an initial BMI of above 45kg/m2. EBMI is a good weight loss indicator, mainly when 95% CI is taken into account. EBMI is consistent with the results obtained 2years after surgery in our patients who underwent SG and RYGBP. Corrected PEBMIL is a good indicator for expressing the percentage of BMI loss and offers more realistic values than conventional formula with a cut-off point of 25 points.