Comparison of weight loss and body composition changes with four surgical procedures.
Analysis of Variance
Body Mass Index
A paucity of information is available on the comparative body composition changes after bariatric procedures. The present study reports on the body mass index (BMI) and body composition changes after 4 procedures by a single group.
At the initial consultation, the weight and body composition of the patients undergoing 4 different bariatric procedures were measured by bioimpedance (Tanita 310). Follow-up examinations were performed at 1 year and at subsequent visits after surgery. Analysis of variance was used to compare the postprocedure BMI and body composition. Analysis of covariance was used to adjust for baseline differences.
A total of 101 gastric bypass (GB) patients were evaluated at 19.1 + or - 10.6 months, 49 biliopancreatic diversion with the duodenal switch (BPD/DS) patients at 27.5 + or - 16.3 months, 41 adjustable gastric band (AGB) patients at 21.4 + or - 9.2 months, and 30 sleeve gastrectomy (SG) patients at 16.7 + or - 5.6 months (P <.0001). No differences were found in patient age or gender among the 4 groups. The mean preoperative BMI was significantly different among the 4 groups (P <.0001): 61.4 kg/m(2), 53.2, 46.7, and 44.3 kg/m(2) for the SG, BPD/DS, GB, and AGB group, respectively. The postoperative BMI adjusted for baseline differences was 27.8 (difference 23.6 + or - 8.3), 32.5 (difference 15.6 + or - 5.0), 37.2 (difference 18.2 + or - 8.2), and 39.5 kg/m(2) (difference 7.5 + or - 4.3) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The percentage of excess weight loss was 84%, 70%, 49%, and 38% for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The postoperative percentage of body fat adjusted for baseline differences was 25.7% (23.9% + or - 7.0%) 32.7% (16.1% + or - 10.5%) 37.7% (16.7% + or - 5.6%), and 42% (6.0% + or - 6.8%) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The lean body mass changes were reciprocal.
Although the BPD/DS procedure reduced the BMI the most effectively and promoted fat loss, all the procedures produced weight loss. The AGB procedure resulted in less body fat loss within 21.5 months than SG within 16.7 months. Longer term observation is indicated.