Study reveals long-term survival benefits of gastric bypass surgery in patients with severe obesity

Patients with severe obesity who have gastric bypass surgery reduce their risk of dying from obesity and other diseases by 48 percent up to 10 years after surgery, compared to similar patients who do not undergo the procedure, according to new research presented today at ObesityWeek 2016, the largest international event focused on the basic science, clinical application and prevention and treatment of obesity. The annual conference is hosted by the American Society for Metabolic and Bariatric Surgery (ASMBS) and The Obesity Society (TOS).

Researchers from the Geisinger Health System followed nearly 2,700 patients who had gastric bypass at the system's nationally accredited bariatric surgery center between 2004 and 2014. Mortality benefits began to emerge within two years after surgery and were significant within four years. The biggest reduction in risk occurred in patients 60 years or older at the time of surgery and in patients who had diabetes before surgery.

"The long-term survival benefits these older patients and those with diabetes experience likely relate to improvements in long-term metabolic and cardiovascular health, among other risk factors," said Michelle R. Lent, Ph.D., a Geisinger Obesity Institute researcher, who presented her team's findings. "While this study did not evaluate specific-cause mortality, as expected, we did find significant improvements or remission in diabetes and high blood pressure."

In the study, more than 60 percent of patients with diabetes before surgery experienced diabetes remission about five years after surgery. Previous studies have shown death from heart disease and even certain cancers are lower in gastric bypass patients than patients with severe obesity who do not have the operation.

"While bariatric surgery provides significant health benefits to most patients, it is important to note that in our study some of the strongest mortality risk reductions following gastric bypass were found in older adults," said Dr. Lent. "Until recently, older age was viewed as a relative contraindication to bariatric surgery, as the benefits were less clear. Our findings help to challenge that myth and instead support offering the surgery to older patients."

People with obesity and severe obesity have higher rates of heart disease, diabetes, some cancers, arthritis, sleep apnea, high blood pressure and dozens of other diseases and conditions. Studies have shown individuals with a BMI greater than 30 have a 50 to 100 percent greater risk of premature death compared to healthy weight individuals.

"Obesity and related diseases kill and the data continues to confirm this fact," said Raul J. Rosenthal, MD, ASMBS President and Chairman, Department of General Surgery, Cleveland Clinic Florida, who was not involved in the study. "The good news is the Geisinger study shows we can do something about it. The long-term data on bariatric surgery provides the proof."

Metabolic/bariatric surgery has been shown to be the most effective and long lasting treatment for severe obesity and many related conditions and results in significant weight loss. The Agency for Healthcare Research and Quality (AHRQ) reported significant improvements in the safety of metabolic/bariatric surgery due in large part to improved laparoscopic techniques. The risk of death is about 0.1 percent and the overall likelihood of major complications is about 4 percent.

According to the Centers for Disease Control and Prevention (CDC), in 2011-2014, the prevalence of obesity was just over 36 percent in adults, with a higher prevalence among women than men (38.3% vs. 34.3%) and older than younger adults (37% vs. 32.3%). Obese is medically defined as having a body mass index (BMI), a measure of height to weight, that's more than 30. The ASMBS estimates about 24 million Americans have severe obesity, which would mean a BMI of 35 or more with an obesity-related condition like diabetes or a BMI of 40.