The emergence of weight loss medications and bariatric surgery presents a promising advance in the fight against obesity. A recent study conducted by researchers at Vanderbilt Health reveals that both these methods significantly enhance body composition for individuals struggling with obesity, leading to a notable decrease in fat mass while also resulting in a moderate loss of fat-free mass, which includes essential lean muscle.
Why is this finding crucial? Higher levels of fat mass (FM) are linked to an increased risk of life-threatening diseases related to obesity, such as heart attacks and strokes. Conversely, possessing a higher percentage of fat-free mass (FFM) can offer protective benefits against mortality. Therefore, understanding how these treatments affect FM and FFM is vital for improving patient outcomes.
The researchers emphasized the need for further investigation into how these body composition changes occur following bariatric surgery or treatment with current GLP-1 receptor agonist drugs in everyday clinical practice. Their findings were published on January 9 in the esteemed journal JAMA Network Open.
Leading the research were Dr. Danxia Yu, an associate professor of Medicine in the Division of Epidemiology, and Dr. Jason Samuels, an assistant professor of Surgery. They conducted a retrospective analysis of electronic health records from 1,257 patients aged 18 to 65 who underwent bariatric surgery at Vanderbilt Health between 2017 and 2022. Additionally, they examined records of 1,809 patients who received medications like semaglutide or tirzepatide from 2018 to 2023. Notably, those with a history of end-stage renal disease or congestive heart failure were excluded from the study.
To assess body composition, the researchers utilized bioelectrical impedance analysis, a technique that estimates FM and FFM based on various individual characteristics, including height, weight, age, race, gender, diabetes history, and duration of GLP-1 treatment.
Over the course of 24 months, the study found that both medical and surgical approaches to weight loss resulted in significant decreases in FM, modest reductions in FFM, and a favorable increase in the FFM/FM ratio, indicating improved body composition overall. Interestingly, male participants exhibited better long-term preservation of FFM compared to their female counterparts.
The first authors of this significant paper included Zicheng Wang, a graduate student, and Lei Wang, a postdoctoral fellow, both specializing in Epidemiology. Other contributors to the research were Xinmeng Zhang and You Chen, PhD, from Biomedical Informatics and Computer Science; Brandon Lowery from the Vanderbilt Institute for Clinical and Translational Research; Lauren Lee Shaffer, MS, and Quinn Wells, MD, from Cardiovascular Medicine; along with Charles Flynn, PhD, Brandon Williams, MD, Matthew Spann, MD, and Gitanjali Srivastava, MD, from Surgery.
This important study was partially funded by grants from the National Institutes of Health, specifically R01DK126721 and R01CA275864.
