Gastric Bypass 'a Viable Treatment' for CV Risk in the Severely Obese

September 19, 2012

September 18, 2012 (Salt Lake City, Utah) — A new study following severely obese participants out to six years after gastric-bypass surgery shows that they had higher rates of diabetes remission and a lower incidence of developing diabetes, compared with nonsurgical controls [1].

The surgical patients also had significantly improved cardiovascular and metabolic risk profiles compared with those who didn't undergo gastric bypass, report Dr Ted Adams (University of Utah School of Medicine, Salt Lake City) and colleagues in a study in the September 19, 2012 issue of the Journal of the American Medical Association. Adams reported the findings at a media briefing in New York today, and he will also present them at Obesity 2012 in San Antonio, TX later this week.

These findings are important because they show . . . that weight loss and associated health benefits following [RYGB] are durable.

"These findings are important because they show, in a Roux-en-Y gastric-bypass [RYGB] cohort and control group with nearly complete follow-up at six years, that weight loss and associated health benefits following RYGB are durable," says Dr Anita P Courcoulas (Minimally Invasive Bariatric and General Surgery, University of Pittsburgh Medical Center, PA) in an accompanying editorial [2].

Adams concurs. "We saw a significant weight loss, which was largely maintained at almost 28% out to six years, which is pretty major given that many cardiovascular studies that have looked at behavior modification have shown about a 6% to 7% weight loss," he told heartwire . "Also, of the patients who had cardiovascular/metabolic problems and had the surgery, a significant number had remission of those problems."

And finally, those in the surgery group who did not have cardiovascular/metabolic problems prior to the operation were also much less likely to develop such problems in the six years after the bypass than the control participants, Adams notes.

"Gastric bypass appears to be a viable treatment for the severely obese as it relates to cardiovascular and metabolic risk and prevention," he observes.

"Remarkable" Follow-up for Surgery Shows Good Control of Comorbidities

The prospective study by Adams et al examined 1156 severely obese people (body-mass index [BMI] >35) aged 18 to 72 years (82% women, mean BMI of 45.9). Of these, 835 sought RYGB surgery, of whom 418 received it but 417 did not (control group 1). The remaining 321 patients (control group 2) were randomly selected from a population-based sample not seeking weight-loss surgery.

The main outcome measures were weight loss, diabetes, hypertension, dyslipidemia, and health-related quality of life, which were compared between participants having RYGB surgery and the two control groups, using propensity-score adjustment.

Gastric bypass appears to be a viable treatment for the severely obese as it relates to cardiovascular and metabolic risk and prevention.

There was some attenuation of weight loss following surgery: at two years, the surgical candidates had lost about 35% of their initial body weight, and by six years this stood at 27.7%, compared with 0.2% gain in control group 1 and 0% in control group 2.

At six years, diabetes remission rates were 62% in the surgery group compared with 6% to 8% in the two control groups, and HDL cholesterol was significantly increased after the surgery compared with controls; this outcome was sustained. "The findings were not as dramatic for high blood pressure, [LDL] cholesterol, and triglycerides," says Adams, although these parameters were all still improved compared with the control groups, he noted.

The incidence of diabetes throughout the course of the study was also reduced after RYGB surgery (2% vs 17% for control group 1 [odds ratio 0.11] and vs 15% for control group 2 [OR 0.21]), representing a five- to ninefold reduction in the risk of new diabetes in surgical patients compared with nonsurgical controls.

Courcoulas observes that "despite the attenuation of weight loss between years 2 and 6 in the RYGB surgery group, the control of comorbid conditions remained very good." She also points out that the study is "remarkable" in that it had a six-year follow-up rate of 93% in the RYGB group, when weight-loss studies "are typically limited by very high dropout rates."

Findings Have Significant Ramifications for Severely Obese Worldwide

The only parameter that was not improved in the surgery group compared with controls was the 36-item Short Form Health Survey mental component, but this was in "contrast with the marked improvements in the SF-36 physical-component score and overall quality-of-life score," say the researchers.

In conclusion, they say their findings "are important considering the rapid increase in the total numbers of bariatric surgical operations performed in the US and worldwide and may have significant ramifications for the projected 31 million US individuals meeting criteria for bariatric surgery."

Adams has no conflicts of interest; disclosures for the coauthors are listed in the paper. Courcoulas reports serving on the scientific advisory board for and as a consultant to Ethicon, a subsidiary of Johnson & Johnson, and having grants pending with Endogastric Solutions, Pfizer, Allergan, Stryker Endoscopy, Coviden, Nutrisystem, the American Society for Metabolic and Bariatric Surgery, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institute on Drug Abuse.