Obese patients who undergo gastric bypass surgery were found to have significantly longer life spans compared to those who do not receive the intervention.

There was no observed reduction in mortality risk after about 30 days following the surgery, but starting five years later the benefits were significant, the University of Virginia Health System reported.

To make their findings, the researchers looked at 401 patients who received gastric bypass at UVA between 2002 and 2003 and 401 obese patients who did not have the surgery.

The team found the five-year mortality rate for the gastric bypass patients was 2.2 percent, compared to 6.7 percent in the obese patients who did not receive the surgery. The 10-year mortality rate for the gastric bypass patients was 6.5 percent, compared with 12.7 percent in the non-surgery group.

The researchers observed similar improvements in survival rates in diabetic patients who underwent gastric bypass when compared with those who did not. The five-year mortality rate for diabetics who received gastric bypass was 3.1 percent compared with 12.4 percent in patients who did not received the surgery.

"The results from this study indicate that for patients who are morbidly obese, treatment with gastric bypass provides a survival advantage," said Dr. Peter T. Hallowell, the study's lead author and director of UVA's bariatric surgery program.

The findings were published in The American Journal of Surgery and the study was funded through a National Institutes of Health training grant.