1. Home>
2. Specialties>
3. General Medicine>
4. Summary and Comment

Does Bariatric Surgery Lower Long-Term Mortality?

Yes, bariatric surgery in morbidly obese patients reduced long-term mortality.

Although it’s reasonable to assume that weight loss after bariatric surgery is associated with decreased long-term mortality, this assumption has not been proven. In two new studies, researchers address this issue.

In a prospective nonrandomized study from Sweden, about 2000 obese people (mean body-mass index, 42 kg/m²) who underwent elective bariatric surgery were compared with a similar number of obese controls matched for 18 variables. Surgical procedures were vertical banded gastroplasty (68%), banding (19%), and gastric bypass (13%). During an average follow-up of 11 years, 5.0% of surgery patients and 6.3% of controls died. In multivariate analysis adjusted for potentially confounding variables, surgery was a significant independent predictor of lower mortality. Ninety-day mortality after surgery was 0.25%.

In a retrospective study from Utah, nearly 8000 patients (mean BMI, 45) who had undergone gastric bypass surgery were compared with the same number of obese matched controls. During an average follow-up of 7 years, 2.7% of patients in the surgery group and 4.1% of controls died; the 40% adjusted relative reduction in mortality associated with surgery was statistically significant. One-year mortality after surgery was 0.5%.

Comment: These two observational studies showed similar reductions in long-term mortality among patients who underwent bariatric surgery. The results are not as conclusive as those from randomized trials would be, but matching between surgery patients and controls was reasonable, and the results are plausible. The extent to which these outcomes can be generalized likely depends on surgical experience and the quality of medical care during the early period after surgery.

— Allan S. Brett, MD

Published in Journal Watch General Medicine August 22, 2007

Citation(s):

Sjöström L et al. Effects of bariatric surgery on mortality in Swedish obese subjects. N Engl J Med 2007 Aug 23; 357:741-52.

• Original article (Subscription may be required)
• Medline abstract (Free)

Adams TD et al. Long-term mortality after gastric bypass surgery. N Engl J Med 2007 Aug 23; 357:753-61.

• Original article (Subscription may be required)
• Medline abstract (Free)