Comparative Effects of Medical vs. Surgical Weight Loss on Body Composition in a Randomized Trial

Abstract

Bariatric surgery leads to more rapid and greater weight loss (WL) compared to medical weight loss (MWL), but differences in body composition changes for these methods of WL remain unclear. Due to the known health risks associated with central adiposity, we sought to understand if changes in regional distribution of fat mass (FM) and lean mass (LM) differ by surgical vs. medical WL. This 1:1:1 randomized trial among 15 persons with type 2 diabetes and BMI 30-39.9 kg/m2 compared changes in body composition (measured by dual energy x-ray absorptiometry) at the time of 10% WL (or nine months after intervention) for patients receiving MWL, adjustable gastric banding (AGB), or Roux-en-Y gastric bypass (RYGB). We used non-parametric tests to evaluate differences across all arms and to compare AGB to RYGB. We present results for the 12 participants who received the study intervention and completed follow-up. All participants were women, and 75% were African American. Time to 10% weight loss was shorter for AGB and RYGB. Total FM losses were similar across arms. While differences across arms were not statistically significant, the AGB arm tended to have greater total LM and peripheral FM losses. In conclusion, at similar overall WL, AGB may lead to preferential loss of peripheral FM and total LM. The change in total FM and truncal FM were similar across all three groups. Larger studies are needed to confirm these findings. MWLAGBRYGBPALLPAGB vs. RYGBN444Age (Years, Mean)4654.351.5Mean BMI, Kg/m2Baseline37.135.535Final353231.6Weight, KgBaseline104.796.394.4Final98.286.985.4% Change-6.1-9.8-10.00.0381.0Time to 10% Weight Loss, months7.472.772.510.0380.77Body Composition OutcomesTotal Fat Mass, KgBaseline50.043.044.5Final45.537.738.9% Change-8.5-12.0-12.90.671.0Truncal Fat Mass, KgBaseline24.424.724.2Final21.722.020.4% Change-11.0-10.9-16.30.670. 77Peripheral Fat Mass, KgBaseline24.217.019.2Final22.614.417.3% Change-5.0-15.0-8.70.670.56Lean Mass, KgBaseline53.251.546.9Final50.444.943.3% Change-5.2-12.4-7.30.070.15Abbreviations: MWL: medical weight loss, AGB: adjustable gastric band, RYGB: Roux-en-Y gastric bypass, BMI: body mass indexPALL for comparison across groups using Kruskal-Wallis testPAGB vs RYGB represents comparison of AGB to RYGB group using Wilcoxon-Mann-Whitney test Disclosure S. Varma: None. T. Brown: Advisory Panel; Self; Merck & Co., Inc.. J. Clark: None. N. Maruthur: None. M. Schweitzer: Consultant; Self; Ethicon US, LLC.. T. Magnuson: None. C. Lee: None.