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Bariatric Surgery Offers Long-term Weight Loss & Diabetes Benefits

As the obesity epidemic continues, many severely overweight patients are turning to gastric bypass surgery to promote weight loss. A new study shows that patients reap a number of health benefits that persist long-term. They not only maintain weight loss but also have a lower incidence of diabetes and high blood pressure. The findings were published on September 20 in the New England Journal of Medicine.

An overview of this project is available here.

The study followed three groups of patients for 12 years — patients who underwent gastric bypass surgery (418), patients who expressed interest in the surgery but whose insurance would not pay for the procedure (417) and patients who did not seek surgery (321).

Patients who underwent the surgical procedure maintained a loss of more than 70 pounds after 12 years compared to only 7 pounds for patients in the two control groups.

"There is a misunderstanding that after this invasive surgery, patients often gain the weight back," said Paul Hopkins, M.D., professor of Internal Medicine at University of Utah Health, who contributed to the project. "We can show in this study that [after this surgical procedure], stable, long-term weight loss is is generally the rule."

In addition to weight loss, the bariatric patients also experienced improvements in blood pressure, blood lipid concentration, and most notably, blood glucose levels. By the end of the study, most patients who had type 2 diabetes before surgery were in remission.

"One of the biggest benefits of gastric bypass surgery, beyond long-term weight loss, was the impact on diabetes," said Hopkins. "If a patient received the surgery early in the course of diabetes, before they were taking medication or before they began treating the disease with insulin injections, we found that 73 percent of patients remained in remission from diabetes."

The pancreas of an overweight person generally has to work harder to produce enough insulin to overcome resistance to the effect of insulin that typically develops in an overweight person. Over time, the pancreas begins to deteriorate, resulting in type-II diabetes. By promoting weight loss early, the pancreas can return to normal function and maintain blood glucose levels.

"If you really want to stop diabetes in its tracks, get this procedure early," said Hopkins.

All of the patients in the surgical group received Roux-en-Y gastric bypass surgery. During the procedure, the stomach is reduced to the size of an egg. The smaller stomach pouch bypasses the upper portion of the small intestine and is reconnected to the middle portion of the small intestine. With a smaller stomach, the patient feels full more quickly and begins to experience weight loss.

The study does note 7 patients died by suicide during 12-year study period, 5 in the surgery group and 2 in the nonsurgery group but who had surgery outside the study. No one in the control groups who did not have surgery took their lives. These findings require additional study to better predict and prevent this uncommon but serious outcome from the surgery.

This study is one of the largest and longest follow-up evaluations of gastric bypass surgery outcomes. The researchers contacted participants in the three groups at specific times during the 12-year period. All participants in the study were characterized as severely obese, more than 100 pounds over their ideal body weight.

"Based upon the findings of this study, gastric bypass appears to be effective for significant, long-term weight loss and for the treatment and prevention of diabetes," said Ted Adams, Ph.D., first author on the paper, a researcher with Intermountain Healthcare and professor in Internal Medicine at U of U Health. "The decision to have gastric bypass surgery should include individual assessment of risks and benefits of the surgery and consultation with one's healthcare provider."


This research received funding from the National Institute of Diabetes and Digestive Kidney Diseases at the National Institute of Health.

The work was published as "Weight and Metabolic Outcomes 12 Years After Gastric Bypass" in NEJM online on September 20.

In addition to Hopkins and Adams, the work was conducted by Lance Davidson, Ph.D., M. Nazeen Manjee, Ph.D., Jonathan Gutierrez, B.S., Sara Frogley, M.B.A., and Steven Hunt, Ph.D from Intermountain Live Well Center Salt Lake, Intermountain Healthcare, as well as Anna Ibele, M.D. and Jaewhan Kim, Ph.D. from U of U Health, Eliot Brinton, M.D., Brigham Young University, Sheldon Litwin, M.D., Medical University of South Carolina, Ronette Kolotkin, Ph.D., Duke University Health System, and Rodrick McKinlay, M.D. and Steven Simper, M.D. from Rocky Mountain Associated Physicians.