What is Bariatric Surgery?

by National Institute of Health

Bariatric surgery restricts stomach size and/or leads to decreased absorption of nutrients. These procedures can have dramatic health benefits, such as improved control of blood sugar or even reversal of type 2 diabetes, but they also carry substantial risks, including death.

How many people have had bariatric surgery?

According to the American Society for Bariatric Surgery (ASBS), the number of procedures increased from about 16,000 in the early 1990s to more than 103,000 in 2003.

Why did NIDDK launch LABS?

A majority of U.S. adults are overweight or obese, with more than 30 percent of adults considered obese (Body Mass Index [BMI] greater than 30). An increasing number of adults are considered extremely obese (BMI greater than or equal to 40). Numerous studies have shown that behavioral therapy to improve diet and physical activity can lead to weight loss of approximately five to ten percent over four to six months. When a person loses weight, obesity-related conditions such as high blood pressure and type 2 diabetes improve, but if a person regains weight, these benefits are lost. In many cases, a person who regains weight ends up weighing more than he or she weighed before the intervention. Doctors need effective weight loss methods for people with extreme obesity and effective ways to maintain long-term weight loss. Currently, the most effective means of losing substantial weight and maintaining that weight loss is through bariatric surgery. Although an increasing number of persons with extreme obesity are undergoing bariatric surgical procedures, there has been little systematic research to help determine its risks and benefits or to provide guidance on appropriate patient selection. To facilitate research in this area, NIDDK established LABS.

What is the goal of LABS?

LABS has brought together experts in bariatric surgery, obesity research, internal medicine, endocrinology, behavioral science, outcomes research, epidemiology, and other relevant fields to plan and conduct studies that will analyze the risks and benefits of bariatric surgery and its impact on the health and well-being of patients with extreme obesity, and identify the kinds of patients who are most likely to benefit.

How will LABS accomplish its goal?

The consortium has developed a database for collecting standardized information on patients undergoing bariatric surgery at the participating clinical centers. Rigorously collected information on patient characteristics, types of surgery, medical and psychosocial outcomes, and economic factors will ultimately provide science-based information on the risks and benefits of bariatric surgery. This information should lead to rational recommendations for clinical care.

LABS will also support clinical studies that are proposed, designed, and approved by the Steering Committee (see below). Examples of the types of questions that might be addressed by such studies include: the impact of surgical procedures on conditions such as insulin resistance and type 2 diabetes. The mechanisms by which bariatric surgery may enhance long-term weight maintenance. The causes of and potential treatments for obesity. For example, examining the impact of restrictive (laparoscopic banding) versus malabsorptive (gastric bypass or biliopancreatic diversion) surgical procedures on hormones presumed to affect appetite may provide insights leading to new, non-surgical obesity treatments that mimic the appetite-suppressive effects of surgery.

LABS Centers will also collect data and specimens for future research. These data will provide a valuable resource for the future study of obesity and its complications.

How is LABS organized?

Through a competitive, peer-reviewed process, principal investigators at six clinical centers and a data coordinating center were funded in September, 2003. These investigators are listed below. The principal investigators at the clinical centers and data coordinating center and the NIH project scientist comprise the Steering Committee, which is the governing body for the consortium. The Steering Committee has met on a frequent basis to develop the database and plan the clinical protocols. Investigators, scientists, and clinicians from the participating centers with relevant expertise are participating in ongoing committees and working groups.

In what other ways might LABS help to advance future obesity research?

LABS may provide the preliminary data needed for future investigator-initiated research on bariatric surgery and obesity. For example, if LABS investigators are able to identify metabolic and endocrine changes that take place after bariatric surgery, this information would allow researchers to submit independent applications for full-scale clinical studies. LABS may encourage researchers to study the causes and treatments of obesity and its related health problems by providing access to laboratory specimens and tissues. The presence of coordinated obesity research efforts at participating institutions may provide opportunities for research and clinical training to students in the health professions, as well as to young investigators. Information on the types of data being collected in the LABS database (not individual patient information) will be made available on the LABS website, so that other interested clinicians and researchers can collect similar data on their patients, facilitating additional research on bariatric surgery.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.