BACKGROUND: Most relative weight-loss metrics follow the formula "Weight loss(%) = 100 · (Initial BMI - Final BMI) / (Initial BMI-a)," where a is the reference point that defines the metric. The percentage of total weight loss (%TWL, a = 0) and percentage of excess weight loss (%EWL, a = 25) are influenced by a patient's initial weight. Recently, the percentage of alterable weight loss metric (%AWL, a = 13) has been reported to produce initial-weight-independent outcomes. OBJECTIVES: This study aimed to replicate the methodology used for %AWL determination in a Mediterranean cohort of bariatric patients. SETTINGS: Multicenter study in 10 large hospitals in Spain. METHODS: Two large prospective databases were retrospectively searched for all primary laparoscopic gastric bypass patients with 2 years of follow-up. Outcomes at nadir were expressed and analyzed with 26 different metrics (a from 0 to 25), looking for the metric whose outcomes produced (1) the lowest coefficient of variation, (2) no differences between initially lighter and heavier patients, and (3) no correlation with patients' initial BMI. RESULTS: A cohort of 1793 patients was stratified into 4 gender-age groups: younger women (YW, n = 733), older women (OW, n = 674), younger men (YM, n = 197), and older men (OM, n = 189). The calculations suggested an optimal reference point of 18 kg/m2, defining a new metric (percentage of Mediterranean alterable weight loss, %MAWL). When %TWL, %EWL, %AWL, and %MAWL were tested on the whole sample, only %MAWL produced initial-weight-independent results. CONCLUSIONS: In our Mediterranean cohort of patients, a reference point of 18 (and not 13) yielded initial-weight-independent outcomes.
BACKGROUND: Most relative weight-loss metrics follow the formula "Weight loss(%) = 100 · (Initial BMI - Final BMI) / (Initial BMI-a)," where a is the reference point that defines the metric. The percentage of total weight loss (%TWL, a = 0) and percentage of excess weight loss (%EWL, a = 25) are influenced by a patient's initial weight. Recently, the percentage of alterable weight loss metric (%AWL, a = 13) has been reported to produce initial-weight-independent outcomes. OBJECTIVES: This study aimed to replicate the methodology used for %AWL determination in a Mediterranean cohort of bariatric patients. SETTINGS: Multicenter study in 10 large hospitals in Spain. METHODS: Two large prospective databases were retrospectively searched for all primary laparoscopic gastric bypass patients with 2 years of follow-up. Outcomes at nadir were expressed and analyzed with 26 different metrics (a from 0 to 25), looking for the metric whose outcomes produced (1) the lowest coefficient of variation, (2) no differences between initially lighter and heavier patients, and (3) no correlation with patients' initial BMI. RESULTS: A cohort of 1793 patients was stratified into 4 gender-age groups: younger women (YW, n = 733), older women (OW, n = 674), younger men (YM, n = 197), and older men (OM, n = 189). The calculations suggested an optimal reference point of 18 kg/m2, defining a new metric (percentage of Mediterranean alterable weight loss, %MAWL). When %TWL, %EWL, %AWL, and %MAWL were tested on the whole sample, only %MAWL produced initial-weight-independent results. CONCLUSIONS: In our Mediterranean cohort of patients, a reference point of 18 (and not 13) yielded initial-weight-independent outcomes.
Entities:
Keywords:
Bariatric surgery; Gastric bypass; Surgery; Weight loss
Authors: Laurent Biertho; Rudolf Steffen; Thomas Ricklin; Fritz F Horber; Alfons Pomp; William B Inabnet; Daniel Herron; Michel Gagner Journal: J Am Coll Surg Date: 2003-10 Impact factor: 6.113
Authors: Ricard Corcelles; Mena Boules; Dvir Froylich; Amani Hag; Christopher R Daigle; Ali Aminian; Stacy A Brethauer; Barto Burguera; Philip R Schauer Journal: Obes Surg Date: 2016-08 Impact factor: 4.129