The study, led by a team of researchers from the University of Utah School of Medicine and LDS Hospital, also found that stomach stapling dramatically reduced deaths from heart disease, cancer, and diabetes in these patients.
The 14-year study examined 15,850 severely obese patients, half of whom underwent gastric bypass surgery to reduce their weight. The mortality rate from coronary heart disease was 56 percent lower in the surgery group than in the non-surgery (control) group. The surgery group also showed a 60 percent lower death rate from cancer and a 92 percent lower death from diabetes than the non-surgery group, according to Ted D. Adams, Ph.D., M.P.H., the study's lead author.
While mortality rates for specific diseases were lower in the surgery group, Adams said that mortality rates from other causes, such as accidents and suicide, were 58 percent higher among those who had the weight loss surgery than the control group.
"This study helps to further define the effects of gastric bypass surgery on long-term mortality. Reduction in death by any cause, and disease-specific deaths such as coronary heart disease, diabetes, and cancer were significantly reduced in surgery patients compared to the non-surgical control group. However, rates of death not caused by disease were shown to be greater in those who underwent the weight-loss surgery when compared to controls," Adams said.
The paper suggests at least some of these non-disease deaths in the surgery group may be due to unrecognised pre-surgical mood disorders or post-traumatic stress disorders, which appear to be more common in severely obese patients.
Adams said the findings are so convincing that they could initiate a major shift in who is eligible for weight-loss surgery, a procedure once referred to the most dangerously obese because of fears about complications.
The study is published in The New England Journal of Medicine.