Adults with severe obesity had greater initial and sustained weight loss with gastric bypass surgery than either sleeve gastrectomy or adjustable gastric banding, according to a new study published in the Annals of Internal Medicine.
This is the largest long-term study of bariatric surgery to date. It included more than 46,000 patients at 41 participating health systems in 11 Clinical Data Research Networks nationwide, thanks to its use of a large new resource called PCORnet, the National Patient-Centered Clinical Research Network.
Bariatric surgeons can use various operations to help people lose weight by making changes to their digestive system.
This study did a head-to-head comparison of 1-, 3- and 5-year results from the three most commonly performed weight-loss operations: gastric bypass, sleeve gastrectomy and adjustable gastric banding.
The findings are important because severe obesity [ a body mass index ( or BMI ) of at least 35 kg/m2 ] affects more than 15% of U.S. adults, according to the National Health and Nutrition Examination Survey.
National Institutes of Health guidelines consider people with a BMI of 40 kg/m2, or at least 35 kg/m2 for people with diabetes mellitus or other obesity-related diseases, eligible for bariatric surgery.
The investigators found that: people who had gastric bypass surgery had lost 31% of their weight at the first year and maintained 26% of their loss at 5 years; people who had sleeve gastrectomy had lost 25% of their pre-surgery body weight at 1 year and maintained 19% weight loss at 5 years.
That translates into a 19-pound difference in weight loss between gastric bypass and sleeve gastrectomy at 5 years for the average person in this study, who weighed 277 pounds before surgery.
By contrast, adjustable gastric banding was much less effective for losing weight and keeping it off, with 14% and 12% of weight lost at 1 and 5 years, respectively.
Gastric banding used to be the most commonly performed bariatric procedure, but it now represents just 10 percent of bariatric procedures.
These findings give strong evidence that bypass and sleeve are effective for lasting weight loss for adults with severe obesity.
Because of the large sample size, the researchers could examine subgroups of people to assess whether certain characteristics improved or worsened their chance of weight loss success.
They found that men, African-Americans, Hispanics, people age 65 and older, and people with diabetes or lower BMIs ( less than 50 ) tended to lose less weight than did other people in the study. But these differences between patient groups were small ( less than 3% differences in weight lost at 1, 3 and 5 years across groups ), which was much less than the differences between the procedures. For instance, the difference between weight lost with gastric bypass and sleeve gastrectomy was 6% at 1 year and 7% at 5 years.
The 30-day risk of major adverse events, such as a prolonged hospitalization or another operation, were generally low across all three procedures.
Sleeve gastrectomy had the lowest rate of major adverse events ( 2.6% ), followed by gastric banding ( 2.9% ), and then gastric bypass ( 5.0% ). ( Xagena )
Source: Kaiser Permanente, 2019