Researchers Take a Closer Look at Weight-Loss Surgeries

A new study on the long-term benefits of gastric bypass surgery, the most commonly performed weight-loss surgery in the U.S., finds that the procedure results in sustained weight loss in the morbidly obese, compared with no surgery, and also helps keeps diabetes and heart disease risk at bay.

The study, published on Tuesday in an obesity-themed issue of the Journal of the American Medical Association, followed 1,156 participants aged 18 to 72 who were severely obese (body mass index, or BMI, of 35 or greater) for more six years. The researchers divided the study sample into three groups: one group of 418 people who underwent surgery, one control group of 417 participants who wanted the surgery but didn’t have it, and a second control group of 321 people who did not seek surgery.

At six years, the researchers found that those who underwent gastric bypass, also known as Roux-en-Y gastric bypass, had significant improvements in their cardiovascular health as well as sustained weight loss compared with other morbidly obese participants who did not undergo surgery: on average, patients who received surgery maintained a loss of 28% of their starting weight for six years. They were also more likely to see their diabetes go into remission: 62% of the gastric bypass group, compared with 8% and 6% in the control groups.

Those who went under the knife also saw improvements in metabolic and heart disease risk factors - they were significantly less likely to have high blood pressure or high cholesterol, for example - during the six years of follow-up. “In contrast, cardiovascular and metabolic status of severely obese control participants generally worsened during the six-year period,” the authors wrote.

“These findings are important considering the rapid increase in total numbers of bariatric surgical operations performed in the United States and worldwide, and may have significant ramifications for the projected 31 million U.S. individuals meeting criteria for bariatric surgery,” the authors concluded.

However, a separate study published on Monday in the Archives of Surgery by researchers at the Madigan Army Medical Center in Fort Lewis, Washington, found that gastric bypass surgery - considered the “gold standard” surgical treatment for obesity - may have a rival: a more complex and less commonly used operation called duodenal switch surgery.

Bariatric surgeries work in two ways: by reducing stomach size or re-routing food from the stomach directly to the intestines, so the body absorbs less of it. Both gastric bypass surgery and duodenal switch combine both methods, but duodenal switch re-routes food significantly more - bypassing most of the small intestine - resulting in less absorption, but also a riskier, more complicated operation and a higher risk of malnutrition afterward. The new study found that both surgeries were successful in leading to weight loss in the morbidly obese, but that weight re-gain may be more common with gastric bypass.