Obese patients who underwent gastric bypass surgery experience weight loss 3 years

University of Pittsburgh Schools of the Health SciencesNov 5 2013

For millions of Americans struggling with obesity and considering surgical procedures to achieve weight loss and alleviate obesity-related health complications, a new study adds weight to the health benefits attributed to bariatric surgery.

Researchers from the University of Pittsburgh's School of Medicine and Graduate School of Public Health and several other clinical centers throughout the country found that most severely obese patients who underwent gastric bypass or laparoscopic adjustable gastric banding surgical procedures experienced substantial weight loss three years after surgery, with most of the change occurring in the first year. The study findings, published online in the Journal of the American Medical Association, also found variability in both weight change and improvements in obesity-related complications, including diabetes, hypertension and high cholesterol.

Gastric bypass and laparoscopic adjustable gastric banding are common bariatric surgical procedures that aid in weight loss by intestinal bypass, stomach restriction, and possibly gut hormone changes.

Led by Anita Courcoulas, M.D., M.P.H., a bariatric and general surgeon at Magee-Womens Hospital of UPMC, researchers used detailed data from the Longitudinal Assessment of Bariatric Surgery (LABS) Consortium, a multicenter observational cohort study, encompassing 10 hospitals in six geographically diverse clinical centers and a data coordinating center, that assesses the safety and efficacy of bariatric surgical procedures performed in the United States. The researchers gathered highly standardized assessments and measures on adult study participants undergoing bariatric surgery procedures and followed them over the course of three years.

At baseline, study participants ranged in age from 18 to 78 years of age, 79 percent were women, and the median Body Mass Index was 45.9 kg/m2; 1,738 participants chose to undergo gastric bypass surgery, and 601 underwent laparoscopic gastric banding.

In the three-year follow-up after bariatric surgery, the researchers observed substantial weight loss for both procedures, with most of the change occurring during the first year. Participants who underwent gastric bypass surgery or laparoscopic adjustable gastric banding experienced median weight loss of nearly 32 percent and 16 percent, respectively.

Additionally, of the gastric bypass surgical participants who had specific obesity-related health problems prior to surgery, 67 percent experienced partial remission from diabetes and 38 percent remission from hypertension. High cholesterol resolved in 61 percent of the participants who underwent bypass surgery. For those who underwent laparoscopic adjustable gastric banding, 28 percent and 17 percent experienced partial remission from diabetes and remission from hypertension respectively, and high cholesterol was resolved in 27 percent of participants.

"Bariatric surgery is not a 'one size fits all' approach to weight loss," cautioned Dr. Courcoulas. "Our study findings are the result of data collected from a multicenter patient population, and emphasize the heterogeneity in weight change and health outcomes for both types of bariatric surgery that we report. Longer-term follow-up of this carefully studied cohort will determine the durability of these improvements over time and identify the factors associated with the variability in effect."