(HealthDay News) – Among obese patients, gastric bypass surgery correlates with higher rates of diabetes remission and lower risk of cardiovascular disease, has little effect on the severity of sleep apnea, and only reduces health care use after the sixth year post-surgery, according to three studies published in the Sept 19 issue of the Journal of the American Medical Association, a theme issue on obesity.

Ted D. Adams, PhD, MPH, of the University of Utah School of Medicine in Salt Lake City, and colleagues conducted a study involving 1,156 severely obese participants (body mass index, ≥35kg/m²) who either received Roux-en-Y gastric bypass (RYGB) surgery (surgery group), requested but did not receive the surgery (control 1), or did not request or receive the surgery (control 2). The researchers found that the surgery group lost 27.7% of their initial body weight, compared to weight gain (0.2%) in control 1 and no change in control 2. Maintenance of weight loss was superior in the surgery group. After six years, diabetes remission rates were significantly up and diabetes incidence was significantly down in the surgery group, compared to both control groups.

In a second study, John B. Dixon, MBBS, PhD, of Monash University in Melbourne, Australia, and colleagues conducted a trial of 60 obese subjects with recently diagnosed obstructive sleep apnea and an apnea-hypopnea index (AHI) of ≥20 events/hour, who either participated in a conventional weight loss program or underwent bariatric surgery (laparoscopic adjustable gastric banding). Even though the bariatric surgery group lost significantly more weight than the diet group, this did not translate into a statistically significant decrease in AHI. In a third study, Martin Neovius, PhD, of the Karolinska Institutet in Stockholm, and colleagues studied long-term (20 years) health care use in patients who underwent bariatric surgery and found that reductions in diabetes and heart medication use did not take effect until the seventh year post-surgery.

“These three studies demonstrate progress in filling the gaps in the bariatric surgery evidence base,” writes the author of an accompanying editorial. “Integrating the ever-growing knowledge base into widely accepted treatment options for severe obesity is a challenge that, if met, will benefit patients, clinicians, the health care system, and public health.”

Several authors from all studies disclosed financial ties to the pharmaceutical, bariatric surgery, and weight loss industries.

Abstract – Adams
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Abstract – Dixon
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Abstract – Neovius
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Editorial (subscription or payment may be required)