An obese woman walks along a beach.Obese patients who undergo gastric bypass surgery are 50 percent less likely to die after 10 years than those who opt for no surgery.

That’s according to a recent study looking at the long-term effects of the procedure.

Researchers from the University of Virginia Health System in Charlottesville found that death rates vary little for the first few years following the surgery, but large differences in survival rates begin to appear within a decade. Their findings were published in the American Journal of Surgery.

The authors conclude that “gastric bypass provides a clear long-term survival advantage compared to non-surgical propensity-matched controls” in obese and morbidly obese patients. Those advantages also extend to diabetic patients.

“The long-term advantages of weight-loss surgery are beginning to become more widely known,” said Kerianne Holman, MD, a board-certified surgeon with Spectrum Health Medical Group bariatrics surgery program. “While diet and exercise are important, alone they provide less than a 5 percent chance of maintaining long-term weight loss. Weight-loss surgery, on the other hand, usually results in a 60 to 80 percent loss of excess body weight at three years and beyond.”

Weight-loss surgery is recommended for patients whose body mass index (BMI) exceeds 40, as well as for patients with BMI between 35 and 40 and at least two obesity-related disorders, such as diabetes, sleep apnea, gastroesophageal reflux disease, high blood pressure and high cholesterol. The BMI is a screening tool calculated from a person’s weight and height. A BMI between 30 and 39.9 is considered obese; a BMI of 40 or above is considered morbidly obese.

During a two-year period beginning in 2002, researchers identified 5,753 patients eligible for gastric bypass; 430 received surgery, while 401 served as a control group. While following patients and controls for more than 11 years, researchers found that:

  • After five years, 2.2 percent of surgery patients had died versus 6.7 percent of the control group
  • After 10 years, 5.4 percent of surgery patients had died versus 11.5 percent of the control group
  • Overall, 6.5 percent of surgery patients had died versus 12.7 percent of the control group

Among diabetics involved in the study:

  • After five years, 3.1 percent of surgery patients had died versus 12.4 percent of the control group
  • After 10 years, 10.2 percent of surgery patients had died versus 19.4 percent of the control group
  • Overall, 12.6 percent of surgery patients had died versus 22.5 percent of the control group

In gastric bypass surgery, a small stomach pouch is created and linked directly to the small intestine.

“The stomach pouch is much smaller than a normal stomach, so that smaller portions of food create a full sensation,” Dr. Holman said. “Further, because a portion of the small intestine is bypassed, fewer calories are absorbed.

“Most importantly, the surgery results in hormonal changes that both decrease hunger and alter the way that the body responds to food, resulting in long-term weight loss and the rapid correction of obesity-related diseases such as diabetes and high blood pressure.”

More recent advances in bariatric surgery include the sleeve gastrectomy, in which 80 percent of the stomach is separated and removed from the body. Similar to gastric bypass, the smaller remaining stomach allows smaller portions of food to create a sensation of fullness. Sleeve gastrectomy also produces the same hormonal changes seen in gastric bypass, leading to decreased hunger, rapid weight loss, and rapid correction of diabetes and high blood pressure.